Connecting Global Priorities: Biodiversity and Human Health
A State of Knowledge Review
Connecting Global Priorities: Biodiversity and Human Health
A State of Knowledge Review WHO Library Cataloguing-in-Publication Data
Connecting global priorities: biodiversity and human health: a state of knowledge review.
1.Biodiversity. 2.Global Health. 3.Public Health. 4.Socioeconomic Factors. 5.Communicable Disease Control. 6.Climate Change. 7.Humans. I.World Health Organization. II.Convention on Biological Diversity.
ISBN 978 92 4 150853 7 (NLM classification: WD 600)
© World Health Organization and Secretariat of the Convention on Biological Diversity, 2015.
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Cover photo credits: (left to right) 1st row i) iStockphoto/pailoolom ii) Conor Kretsch iii) Glen Bowes 2nd row i) Danny Hunter ii) Bioversity International iii) A.Camacho 3rd row i) Glen Bowes ii) Jon Betz / NGS iii) Barry Kretsch 4th row i) iStockphoto/ rssfhs ii) iStockphoto iii) Ecohealth Alliance
Editing and design by Inís Communication (www.iniscommunication.com) CONOR KRETSCH Acknowledgements
This volume was jointly prepared by the Secretariat of the Convention on Biological Diversity and the World Health Organization, in collaboration with several partners including: Bioversity International, COHAB Initiative, DIVERSITAS, Ecohealth Alliance, Food and Agriculture Organization of the United Nations (FAO), Harvard School of Public Health (HSPH), Platform for Agrobiodiversity Research (PAR), United Nations University-Institute for Advanced Studies (UNU-IAS), United Nations University -International Institute for Global Health (UNU-IIGH), Wildlife Conservation Society, Health and Ecosystems Analysis of Linkages (WCS-HEAL) and several other partners and experts.
The World Health Organization and the Secretariat of the Convention on Biological Diversity, wish to express particular gratitude to the numerous authors and contributors to this volume without whom this unique volume would not have been possible.
WHO and SCBD also wish to extend their gratitude to the following reviewers: Maria Purificacion Neira (WHO), Sir Andy Haines (Chair of the The Lancet-Rockefeller Foundation Commission on Planetary Health), Carlo Blasi (Sapienza University of Rome), Luiz Augusto Cassanha Galvão (PAHO), Ruth Charrondiere (FAO), Florence Egal, Pablo Eyzaguirre (Bioversity International), Jessica Fanzo (Columbia University), Viviana Figueroa (CBD Secretariat), Trevor Hancock (University of Victoria), Danna Leaman (IUCN, MPSG-SSC), Markus Lehmann (CBD), Catherine Machalaba (EcoHealth Alliance), Keith Martin (CUGH), Jonathan Patz (Global Health Institute, University of Wisconsin), Simone Schiele (CBD Secretariat), Cristina Tirado (UCLA), and the numerous Parties, Governments and other peer reviewers who participated in two open peer review processes and in the final consultation held at IUCN World Parks Congress in Sydney, Australia.
WHO and SCBD additionally wish to thank the following individuals and organizations: Flavia Bustreo (WHO) Annie Cung (CBD), David Ainsworth (CBD), Didier Babin (CIRAD), Mateusz Banski (CBD), Charles Besancon (CBD), Francesco Branca (WHO), Kathryn Campbell (Parks Victoria, Australia), Kimberly Chriscaden (WHO), Stéphane de la Rocque (WHO/OIE), Carlos Francisco Dora (WHO), Beatriz Gomez Castro (CBD), Samantha Collins (Bioversity International), Annie Cung (CBD), Jennifer Garard, Bruce Allan Gordon (WHO), Johan Hedlund (CBD), Kahoru Kanari, Sakhile Koketso (CBD), Lina Mahy (WHO/SCN), Yukiko Maruyama (WHO), Tanya McGregor (CBD), Christian Morris (CBD), Sabina Moya Huerta (WHO), Liz Mumford (WHO), Trang Nguyen (Bioversity International), Steve Osofsky (WCS), Nada Osseiran (WHO), Michaela Pfeiffer (WHO), Neil Pratt (CBD), Cathy Roth (WHO), Catalina Santamaria (CBD), Yahaya Sekagya, Negar Tayyar (UNU-IAS), Billy Tsekos (CBD), Ann Tutwiler (Bioversity International), Kieran Noonan Mooney (CBD), Anthony Ramos (EcoHealth Alliance), Shekar Saxena (WHO), Mohammad Taghi Yasamy (WHO), Stephan Weise (Bioversity International), Sarah Whitmee (Lancet – Rockefeller Foundation Commission on Planetary Health), Ekaterina Yakushina, Elena Villalobos (WHO), Qi Zhang (WHO), Camilla Zanzanaini (Bioversity International), United Nations Food and Agriculture Organization (FAO), Alexander von Humboldt Institute, Australian National University, Biodiversity Institute of Ontario, CONABIO, Global Crop Diversity Trust, Inís Communication, Loyola Sustainability Research Centre (LSRC), International Union for the Conservation of Nature (IUCN), Parks Victoria, Australia, Organization for Animal Health (OIE), TRAFFIC, and World Agroforestry Centre (ICRAF).
The production of the State of Knowledge Review was enabled through financial and in kind contributions from the European Commission and the Government of France.
PAR platform for agrobiodiversity research Chapter authors
Lead coordinating authors: Cristina Romanelli, David Cooper, Diarmid Campbell-Lendrum, Marina Maiero, William B. Karesh, Danny Hunter and Christopher D. Golden
PART I
chapter and chapter : Introduction to the state of knowledge review / Biodiversity and human health linkages: concepts, determinants, drivers of change and approaches to integration Lead authors: Cristina Romanelli, David Cooper, Marina Maiero, Diarmid Campbell-Lendrum, Elena Villalobos, Johannes Sommerfeld and Mariam Otmani del Barrio Contributing authors: William B. Karesh, Catherine Machalaba, Anne-Hélène Prieur-Richard, Daniel Buss, Christopher D. Golden, and Lynne Gaffikin
PART II
chapter : Freshwater, wetlands, biodiversity and human health Lead authors: Cristina Romanelli and Daniel Buss Contributing authors: David Coates, Toby Hodgkin, Peter Stoett, and Ana Boischio
chapter : Biodiversity, air quality and human health Lead authors: David Nowak, Sarah Jovan Contributing authors: Cristina Branquinho, Sofia Augusto, Manuel C Ribeiro and Conor E. Kretsch
chapter : Agricultural biodiversity and food security Lead authors: Toby Hodgkin and Danny Hunter Contributing authors: Sylvia Wood, Nicole Demers
chapter : Biodiversity and nutrition Lead authors: Danny Hunter, Barbara Burlingame, Roseline Remans Contributing authors: Teresa Borelli, Bruce Cogill, Lidio Coradin, Christopher D. Golden, Ramni Jamnadass, Katja Kehlenbeck, Gina Kennedy, Harriet Kuhnlein, Stepha McMullin, Samuel Myers, Daniela Moura de Oliveira Beltrame, Alberto Jorge da Rocha Silva, Manika Saha, Lars Scheerer, Charlie Shackleton, Camila Neves Soares Oliveira, Celine Termote, Corrado Teofili, Shakuntala Thilsted, and Roberto Valenti.
chapter : Infectious diseases Lead authors: William B. Karesh and Pierre Formenty Contributing authors: Christopher Allen, Colleen Burge, Marcia Chame dos Santos, Peter Daszak,
iv Connecting Global Priorities: Biodiversity and Human Health Piero Genovesi, Jacqueline Fletcher, Pierre Formenty, Drew Harvell, William B. Karesh, Richard Kock, Elizabeth H. Loh, Juan Lubroth, Catherine Machalaba, Anne-Hélène Prieur-Richard, Kristine M. Smith, Peter J. Stoett, and Hillary S. Young. chapter : Environmental microbial diversity and noncommunicable diseases Lead Authors: Graham A.W. Rook and Rob Knight chapter : Biodiversity and biomedical discovery Lead author: Aaron Bernstein chapter : Biodiversity, health care & pharmaceuticals Lead authors: Alistair B.A. Boxall and Conor E. Kretsch chapter : Traditional medicine Lead authors: Unnikrishnan Payyappallimana and Suneetha M. Subramanian Contributing authors: Anastasiya Timoshyna, Bertrand Graz, Danna Leaman, Rainer W. Bussman, Hariramamurthi G., Darshan Shankar, Charlotte I.E.A. van’t Klooster, Gerard Bodeker, Yahaya Sekagya, Wim Hemstra, Felipe Gomez, Bas Verschuuren, Eileen de Ravin, James Ligare, Andrew M. Reid and Leif M. Petersen chapter : Contribution of biodiversity and green spaces to mental and physical fitness, and cultural dimensions of health Lead Authors: Pierre Horwitz and Conor Kretsch Contributing Authors: Aaron Jenkins, Abdul Rahim bin Abdul Hamid, Ambra Burls, Kathryn Campbell, May Carter, Wendy Henwood, Rebecca Lovell, Lai Choo Malone-Lee, Tim McCreanor, Helen Moewaka- Barnes, Raul A. Montenegro, Margot Parkes, Jonathan Patz, Jenny J Roe, Cristina Romanelli, Katesuda Sitthisuntikul, Carolyn Stephens, Mardie Townsend, Pam Wright
PART III chapter : Climate change, biodiversity and human health Lead authors: Cristina Romanelli, Anthony Capon, Marina Maiero, Diarmid Campbell-Lendrum Contributing authors: Colin Butler, Carlos Corvalan, Rita Issa, Ro McFarlane, and M. Cristina Tirado- von der Pahlen chapter : Increasing resilience and disaster risk reduction: the value of biodiversity and ecosystem approaches to resistance, resilience and relief Lead Authors: R. David Stone, Emma Goring and Conor E. Kretsch chapter : Population, consumption and the demand for resources; pathways to sustainability Lead Authors: Cristina Romanelli, David Cooper chapter : Integrating health and biodiversity: strategies, tools and further research Lead Authors: David Cooper, Cristina Romanelli, Marina Maiero, Diarmid Campbell-Lendrum, Carlos Corvalan and Lynne Gaffikin, Contributing authors: Kevin Bardosh, Daniel Buss, Emma Goring, William B. Karesh, Conor Kretsch, Christopher D. Golden, Catherine Machalaba, Mariam Otmani del Barrio and Anne-Hélène Prieur-Richard
Connecting Global Priorities: Biodiversity and Human Health v Table of Contents
Forewords ______ix Preface ______xi Executive Summary ______1
Part I. Concepts, Themes & Directions
1. Introduction to the State of Knowledge 2. EQUITY AND SOCIAL DIMENSIONS OF Review ______24 HEALTH AND BIODIVERSITY ______30 3. BIODIVERSITY, ECOSYSTEM FUNCTIONS 2. Biodiversity and human health linkages: AND SERVICES ______33 concepts, determinants, drivers of 4. DRIVERS OF CHANGE ______37 change and approaches to integration 28 5. INTEGRATING BIODIVERSITY AND HUMAN 1. BIODIVERSITY, HEALTH AND HEALTH: APPROACHES AND FRAMEWORKS 41 INTERACTIONS ______28 6. CONCLUSION: A THEMATIC APPROACH TO COMMON LINKAGES ______43
Part II. Thematic Areas in Biodiversity & Health
3. Freshwater, wetlands, biodiversity 4. Biodiversity, air quality and human and human health ______46 health ______63 1. Introduction ______46 1. Introduction ______63 2. Water resources: an essential ecosystem 2. Air pollution and its effects on human health _63 service ______47 3. Impacts of vegetation on air quality ______64 3. Dual threats to freshwater ecosystems and human health ______49 4. The oler of plant biodiversity in regulating air quality ______67 4. Impacts of agriculture on water ecosystems and human health ______54 5. Impacts of air quality on plant communities __71 5. Waterborne and water-related diseases ______56 6. Bioindicators ______72 6. Ways forward and additional considerations __61 7. Knowledge gaps and ways forward ______74
vi Connecting Global Priorities: Biodiversity and Human Health 5. Agricultural biodiversity, food 8. Environmental microbial diversity security and human health ______75 and noncommunicable diseases ____150 1. Introduction ______75 1. Introduction ______150 2. Agricultural biodiversity ______76 2. The ‘hygiene hypothesis’: the updated concept 150 3. Agricultural production, land use, ecosystem 3. Commensal microbiotas and environmental services and human health ______78 biodiversity ______153 4. Food production, food security and human 4. Loss of biodiversity: consequences for health______89 human health ______153 5. Conclusions ______95 5. Commensal microbiota and noncommunicable diseases ______157 6. Biodiversity and Nutrition ______97 6. Ways forward: preliminary recommendations 1. Introduction ______97 for global and sectoral policy ______159
2. Biodiversity and food composition ______99 9. Biodiversity and biomedical discovery 164 3. Systems diversity and human nutrition _____102 1. Introduction ______164 4. Wild foods and human nutrition ______107 2. Why biodiversity matters to medical discovery 164 5. Biodiversity and traditional food systems ___112 3. Biodiversity, the microbiome and 6. Biodiversity and the nutrition transition ____114 antimicrobial resistance ______167 7. Nutrition, biodiversity and agriculture in the 4. Future challenges: implications of context of urbanization ______117 biodiversity loss for medical discovery _____168 8. Food cultures: local strategies with global 5. Ways forward: conservation as a public policy implications ______119 health imperative ______169
9. Mainstreaming biodiversity for food and 10. Biodiversity, health care nutrition into public policies ______122 & pharmaceuticals ______170 10. Global policy initiatives ______124 1. Introduction ______170 11. Ways forward: toward a post-2015 development agenda ______127 2. Inputs and occurrence of active pharmaceutical ingredients (APIs) ______172 7. Infectious diseases ______130 3. Impacts of pharmaceuticals on biodiversity and ecosystem services ______174 1. Introduction and background ______130 4. Future challenges: effects of social and 2. Infectious disease ecology and drivers ______132 environmental changes ______177 3. Challenges and approaches ______144 5. Ways forward: reducing the impact of APIs in the environment ______179
Connecting Global Priorities: Biodiversity and Human Health vii 11. Traditional medicine______180 12. Contribution of biodiversity and green 1. Introduction ______180 spaces to mental and physical fitness, and cultural dimensions of health ___200 2. Trends in demand for biological resources ___181 1. Introduction ______200 3. Traditional medicine and traditional knowledge at a crossroads ______188 2. Biodiversity and mental health ______201 4. Strengthening traditional health practices 3. Biodiversity, green space, exercise and health _205 and addressing loss of resources ______189 4. The ontributionc of biodiversity to cultural 5. Challenges to the protection of traditional ecosystem services that support health and medical knowledge ______193 well-being ______212 6. Ways forward ______196 5. Conclusions and ways forward ______219
Part III: Cross-Cutting Issues, Tools & Ways Forward
13. Climate change, biodiversity and 4. Global trends to 2050 and pathways to human health ______222 sustainability ______254 1. Introduction ______222 5. Conclusion ______257 2. Climate change challenges at the intersection 16. Integrating health and biodiversity: of biodiversity and human health ______227 strategies, tools and further 3. Ways forward ______235 research ______258 4. Conclusion ______236 1. Introduction ______258 2. Strategic objectives for the integration of 14. Increasing resilience and disaster risk biodiversity and human health ______258 reduction: the value of biodiversity and ecosystem approaches to 3. Priority interventions for the integration of biodiversity and human health ______261 resistance, resilience and relief ____238 4. Towards the development of common 1. Introduction ______238 metrics and approaches ______263 2. Biodiversity and disaster risk reduction: 5: Keeping tabs: The need for monitoring and prevention and mitigation ______240 accountability for evidence-based indicators 3. Specific considerations for internally at the intersection of biodiversity and health 265 displaced persons and refugees ______246 6. Assessing the economic value of biodiversity and health: benefits and limitations ______266 15. Population, consumption and the demand for resources; pathways 7. Shaping behaviour and engaging communities for transformational change __269 to sustainability ______251 8. Research needs ______271 1. Introduction ______251 9. Integrating biodiversity and health into the 2. Current Trends and Alternatives ______252 sustainable development agenda ______272 3. Consumption – the demand for food and energy ______253
References ______276
viii Connecting Global Priorities: Biodiversity and Human Health CONOR KRETSCH Braulio Ferreira Dias de Souza Diversity Foreword oftheConvention by onBiological theExecutive Secretary Forewords Executive Secretary, Convention on Biological Diversity Assistant Secretary General oftheUnited Nations Secretary Executive Secretary, DiversityAssistant Convention onBiological coordinated solutionsthat jointlyreduce threats better equippedto developrobust, coherent and webecome healthanddevelopment, global loss, biodiversity, between of thevitallinks itspersistent science continues toAs unravel ourunderstanding forour common sustainable development. agenda for essential benefits allpeople”. are They central to sustainingahealthy anddelivering planet services, restored andwiselyused,maintainingecosystem isvalued,conserved, 2050 Vision:“Biodiversity forStrategic Plan Biodiversity, andreflected inits human healthare deeplyentrenched inthe ecosystems, theprovision and ofthesebenefits inexorable biodiversity, between The links and noncommunicablediseases. confront to stem thetideofinfectious ourefforts puzzlethat component oftheepidemiological andeachanimportant our healthandwell-being, functions hasdirect andindirect consequences for climate changeandnatural disasters. ofthese Each the regulation of pestsanddiseaseto that of functionsthat range critical fromand perform tocontribute theprovision ofcleanwater andair, also They enrichment. and cultural andspiritual medicinal compounds, fuel,energy, livelihoods medicinesandof food nutrients, andessential includinghumanlife. are They the planet, sources deliverthat are they central pillarsfor alllife on Biodiversity, ecosystems services andtheessential Connecting Global Priorities:Biodiversity andHuman Health not compoundnot butrather helpto face thepublic name ofbiodiversity, sectors healthorother do We made inthe mustensure that interventions generously thisto fruition. to contributed bring who andexperts andallpartners Organization I amespeciallygrateful to theWorld Health step inthisdirection.review isaconstructive state ofknowledge This services. supporting the forces that impedetheirabilityto deliverlife- ecosystemstrengthening resilience andmitigating us to developeffective solutionscapableof areinfluences bywhichthey mediated, enables these complex relationships at allscales,andthe Increasingthat sustainsit. of ourknowledge to humanlife andto environment thesurrounding sustainable, agenda in2015andbeyond. sustainable, agenda pave theroad toward amore equitable,andtruly threats that weface. inthisway Only canwetruly to commonsolutions thecommon development of alike to can–andmustcontribute citizens the makers, scientists,educators, communities and present andfuture generations. sectors, policy- All thegrowing needsof capableofmeeting planet in thepursuitofahealthier, more sustainable habitats. Weperi-urban are allstakeholders zonesandurban into intensive agricultural the transformation ofonce natural landscapes pressures,socio-demographic travel, trade and challengesposedbyrising health andconservation ix Foreword by the Director, Public Health, Environmental and Social Determinants of Health, World Health Organization
At WHO, we are aware of the growing body of epidemic infectious diseases such as the Ebola evidence that biodiversity loss is happening virus; and the connection between biodiversity, at unprecedented rates. There is increasing nutritional diversity and health. It also covers recognition that this is a fundamental risk to the the potential benefits of closer partnerships healthy and stable ecosystems that sustain all between conservation and health, from improved aspects of our societies. surveillance of infectious diseases in wildlife and human populations, to promoting access to green Human health is not immune from this threat. All spaces to promote physical activity and mental aspects of human wellbeing depend on ecosystem health. Of course, it also highlights the many areas goods and services, which in turn depend on in which further research is needed. biodiversity. Biodiversity loss can destabilize ecosystems, promote outbreaks of infectious We hope this joint report will be able to help disease, and undermine development progress, policy makers to recognize the intrinsic value of nutrition security and protection from natural biodiversity and its role as a critical foundation disasters. for sustainable development and human health and well-being. Protecting public health from these risks lies outside of the traditional roles of the health In particular, we hope the report provides a useful sector. It relies on working with partners engaged reference for the Sustainable Development Goals in conservation, and the sustainable use and and post-2015 development agenda, which management of natural resources. represents an unique opportunity to promote integrated approaches to biodiversity and health In this regard, WHO appreciates the leadership by highlighting that biodiversity contributes that the Secretariat of the Convention on to human well-being, and highlighting that Biological Diversity has shown in promoting the biodiversity needs protection for development to linkages between biodiversity and health. be sustainable.
The report synthesizes the available information WHO looks forward to working jointly with our on the most important inter-linkages; for example CBD colleagues, and the wider conservation between biodiversity, ecosystem stability, and community, to support this important agenda.
Dr. Maria Neira Director, Public Health, Environmental and Social Determinants of Health, World Health Organization
x Connecting Global Priorities: Biodiversity and Human Health GLEN BOWES Planetary Health Planetary Preface by theChair oftheRockefeller-Lancet Commission on Preface and Professor of Primary Care at the London School of Hygiene andTropical Care ofHygiene School at Medicine theLondon and Professor ofPrimary Health andProfessor ofPublicHealth Foundation oftheLancet-Rockefeller CommissiononPlanetary Chair Professor SirAndyHaines ofactions to reduce andthebenefits them. in ourunderstandingoftheserisks thatunderstand, andrespond weourselveshave to therisks created advance is amajor andthisReview isto develop Health overthecoming century Planetary Diversity andtheWorldgreatest The on Biological Health challenge Organization. to protecting State from Knowledge Review of theConventionThe Commissionwelcomes thistimelyandimportant inJuly2015. Lancet inThe of apeer-reviewed CommissionReport since thepublication July2014,andwill conclude itsworkthrough The Commissionhasbeenunderway insectors working that influence health,development andthebiosphere.community andpolicymakers out Health) andset recommendations for action to thehealth Planetary systems (TheCommissionon to ofEarth’s review thescientificbasisfor humanhealthto natural linking theunderlyingintegrity In response Lancet, have aCommission to TheRockefeller thesechallenges, formed andThe Foundation relationships across researchdisciplinary themesare environment andbuildinginter- andcommunicating ofco-benefits andhealth,identifying examples thebiosphereboth andhumanhealthliewithinreach. Improving theevidence between baseoflinks cause for hope.Theinterconnected nature ofpeople and willlikely become thedominantthreat century. to healthover thenext there But isalsomuch uncheckedthesechangesthreatenLeft to reverse healthgains ofthelastseveral decades theglobal pollution,andbiodiversityloss; havedegradation, systems; growing water includingaccelerating scarcity, landdegradation, climatic disruption, fisheries systems.to Theimpacts andbiogeochemical theEarth’s oftransformations ecological to these has,however, conventional Thishumanflourishing been degradation at the cost ofextensive metrics. The last50 years have seenunprecedented improvements inhumanhealth,asmeasured bymost and prosperity. wherebuild apost-2015 ahealthy agenda biosphere asaprecondition isrecognised for humanhealth Connecting Global Priorities:Biodiversity andHuman Health already begun to impacthumanhealth. negatively already begun and the planet meanthat solutionsthat andtheplanet benefit key challengeswhichmustbeaddressed,key to help the capability of human civilisations, to interpret, the capabilityofhumancivilisations, to interpret, xi Biodiversity and
Nutrition Agricultural Health “is a state of biodiversity complete physical, mental and social well-being and not merely the absence of disease or inƥrmityŚ.
Mental health
Biological diversity Food & Water (biodiversity) is “the variability security among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within Sustainable Hea species, between species and development outco of ecosystems.Ś
Biomedical/ pharmaceutical Biodiversity discovery underpins ecosystem functioning and the provision of goods and services that are essential to human health and Traditional well being. medicine
The links between biodiversity and health are manifested at various spatial and temporal Biodiv scales. Biodiversity and human health, and the respective policies and activities, are interlinked in various ways. human health
Disaster risk Direct drivers of biodiversity loss include Air quality land-use change, habitat loss, over-exploitation, pollution, invasive species and climate change. Many of these drivers Water quality aƤect human health directly and through their impacts on biodiversity.
Climate change Women and men have diƤerent roles in the conservation and use of biodiversity and varying health impacts. alth omes
Microbial biodiversity Ecosystems Human population health is determined, to a large extent, by social, eco- nomic and environmental factors.
Infectious diseases
The social and natural sciences are important contributors to biodiversity and health research and policy. Integra- tive approaches such as the versity Ecosystem Approach, Eco- health and One Health unite diƤerent ƥelds and require the development of mutual understanding and coopera- tion across disciplines.
GLEN BOWES Executive Summary
INTRODUCTION 1. Health “is a state of complete physical, 3. Biodiversity underpins ecosystem mental and social well-being and functioning and the provision of goods not merely the absence of disease or and services that are essential to human infirmity”. This is the definition of the health and well-being. Ecosystems, World Health Organization. Health status including our food production systems, has important social, economic, behavioural depend on a whole host of organisms: and environmental determinants and wide- primary producers, herbivores, carnivores, ranging impacts. Typically health has been decomposers, pollinators, pathogens, viewed largely in a human-only context. natural enemies of pests. Services provided However, there is increasing recognition of by ecosystems include food, clean air and the broader health concept that encompasses both the quantity and quality of fresh water, other species, our ecosystems and the integral medicines, spiritual and cultural values, ecological underpinnings of many drivers or climate regulation, pest and disease regulation, protectors of health risks. and disaster risk reduction. Biodiversity is a key environmental determinant of human 2. Biological diversity (biodiversity) is “the health; the conservation and the sustainable variability among living organisms from use of biodiversity can benefit human health all sources including, inter alia, terrestrial, by maintaining ecosystem services and by marine and other aquatic ecosystems and maintaining options for the future. the ecological complexes of which they are part; this includes diversity within species, 4. The links between biodiversity and between species and of ecosystems.” This health are manifested at various spatial definition of the Convention on Biological and temporal scales. At a planetary scale, Diversity (Article 2) reflects different levels ecosystems and biodiversity play a critical role of biodiversity (including genetic diversity, in determining the state of the Earth System, species and ecosystems) and the complexities regulating its material and energy flows and its of biotic and abiotic interactions. The responses to abrupt and gradual change. At a attributes and interactions of biotic and more intimate level, the human microbiota – abiotic components determine ecosystem the symbiotic microbial communities present processes and their properties. The effective on our gut, skin, respiratory and urino-genital management of ecosystems as part of tracts, contribute to our nutrition, can help comprehensive public health measures regulate our immune system, and prevent requires that these various complex linkages infections. and interactions be identified and understood.
Connecting Global Priorities: Biodiversity and Human Health 1 5. Biodiversity and human health, and and economic processes. Social change and the respective policies and activities, development trends (such as urbanization), are interlinked in various ways. First, poverty and gender also influence these biodiversity gives rise to health benefits. drivers of change. Macro-economic policies For example, the variety of species and and structures and public policies that provide genotypes provide nutrients and medicines. perverse incentives or fail to incorporate the Biodiversity also underpins ecosystem value of biodiversity often compound the dual functioning which provides services such as threat to biodiversity and public health. water and air purification, pest and disease control and pollination. However, it can also 7. Human population health is determined, be a source of pathogens leading to negative to a large extent, by social, economic and health outcomes. A second type of interaction environmental factors. Social determinants arises from drivers of change that affect both of health include poverty, gender, sex, age, biodiversity and health in parallel. For example, and rural versus urban areas. Vulnerable air and water pollution can lead to biodiversity people, and groups (such as women and loss and have direct impacts on health. A third the poor) who tend to be more reliant on type of interaction arises from the impacts of biodiversity and ecosystem services suffer health sector interventions on biodiversity disproportionately from biodiversity loss and of biodiversity-related interventions and have less access to social protection on human health. For example, the use of mechanisms (for example, access to pharmaceuticals may lead to the release of healthcare). A social justice perspective is active ingredients in the environment and needed to address the various dimensions of damage species and ecosystems, which in turn equity in the biodiversity and health dynamic. may have negative knock-on effects on human Vulnerability and adaptation assessments are health. Protected areas or hunting bans could needed and should be tailored to the contexts deny access of local communities to bushmeat of these populations. and other wild sourcs of food and medicines with negative impacts on health. Positive 8. Women and men have different roles in the interactions of this type are also possible; for conservation and use of biodiversity and example the establishment of protected areas varying health impacts. Access to, use, and may protect water supplies with positive management of biodiversity has differential health benefits. gender health impacts shaped by respective cultural values and norms which in turn 6. Direct drivers of biodiversity loss include determine roles, responsibilities, obligations, land-use change, habitat loss, over- benefits and rights. Institutional capacity and exploitation, pollution, invasive species legal frameworks often inadequately reflect and climate change. Many of these differential gender roles. There is also a lack drivers affect human health directly and of gender disaggregated data on biodiversity through their impacts on biodiversity. The access, use and control and on the differential continued decline of biodiversity, including health impacts of biodiversity change. loss or degradation of ecosystems, is reducing the ability of biodiversity and ecosystems to 9. The social and natural sciences are provide essential life-sustaining services and, important contributors to biodiversity in many cases, leads to negative outcomes for and health research and policy. Integrative health and well-being. Ecosystem degradation approaches, such as the ecosystem may lead to both biodiversity loss and approach, ecohealth and One Health, increased risk from infectious diseases. In unite different fields and require the turn, the indirect drivers of biodiversity loss development of mutual understanding are demographic change and large-scale social and cooperation across disciplines.
2 Connecting Global Priorities: Biodiversity and Human Health Multi-disciplinary research and approaches and quality of water supply but are themselves can provide valuable insights on the drivers degraded by pollution. of disease emergence and spread, contribute to identifying previous patterns of disease risk, 10. Ecosystems provide clean water that and help predict future risks through the lens underpin many aspects of human health. of social-ecological systems. Such challenges All terrestrial and freshwater ecosystems necessitate engagement of many stakeholders, play a role in underpinning the water cycle including governments, civil society, and non- including regulating nutrient cycling and soil governmental and international organizations. erosion. Many ecosystems can also play a role Integrative approaches such as these make it in managing pollution; the water purification possible to maximize resource efficiency as services they provide underpin water quality. well as conservation, health and development Mountain ecosystems are of particular outcomes. While their value is increasingly significance in this regard. Many protected recognized for infectious disease prevention areas are established primarily to protect water and control, their wider applications and supplies for people. benefits can also extend to other areas. For example, to the assessment of environmental 11. Freshwater ecosystems, such as rivers, lakes health exposures and outcomes, better and wetlands, face disproportionately high understanding of the health services provided levels of threats due largely to demands on by biodiversity, and of how anthropogenic water and impacts of human activities such changes to an ecosystem or biodiversity may as dam construction and mining. In some influence disease risks. regions, up to 95% of wetlands have been lost and two-thirds of the world’s largest rivers are now moderately to severely fragmented WATER, AIR QUALITY AND HEALTH by dams and reservoirs. Freshwater species have declined at a rate greater than any other biome, with the sharpest decline in tropical freshwater biomes. More than one-third of the accessible renewable freshwater on earth is consumptively used for agriculture, industrial and domestic use, which often leads to chemical pollution of natural water sources. Other human activity, such as mining, can also lead to bioaccumulation and biomagnification.
12. Impaired water quality results in significant social and economic costs. Ecosystem degradation–for example through eutrophication caused by excessive nutrients– is a major cause of declines in water quality. Left untreated, poor quality water results in massive burdens on human health, with the ERIC SALES / ASIAN DEVELOPMENT BANK FLICKR most pronounced impacts on women, children Access to clean water is fundamental to human health and the poor. Maintaining or restoring healthy and a priority for sustainable development. Yet, ecosystems (for example, through protected almost 1 billion people lack access to safe drinking areas) is a cost-effective and sustainable way water and 2 million annual deaths are attributable to to improve water quality while also benefitting unsafe water, sanitation and hygiene. Biodiversity and biodiversity. ecosystems play a major role in regulating the quantity
Connecting Global Priorities: Biodiversity and Human Health 3 13. Water-related infrastructure has positive buildings, ecosystems in cities alter energy and negative impacts on biodiversity, use and consequent greenhouse gas emissions; livelihoods, and human health. Altered (3) Emissions – many ecosystems emit volatile waterways (e.g. dams, irrigation canals, organic carbons (VOCs) including terpenes urban drainage systems) can provide valuable and arenes. While sometimes considered benefits to human communities, but may be as pollutants, many natural VOCs play a costly to build and maintain, and in some critical role in atmospheric chemistry and air cases increase risks (e.g. flood risk from coastal quality regulation. Ecosystems also release wetlands degradation). They can also diminish pollen, sometimes associated with acute native biodiversity and sometimes increase respiratory problems. Burning of vegetation the incidence of water-borne or water-related is also associated with significant pollution illnesses such as schistosomiasis. Approaches emissions. integrating benefits of both physical/built and natural infrastructure can provide more 15. Components of biodiversity can be used sustainable and cost-effective solutions. as bioindicators of known human health stressors, as well as in air and water quality mapping, monitoring, and regulation. Lichens are among the most widely utilized and well-developed indicators of air quality to date and are making headway as reliable indicators for air quality regulation. The shift in species is predictable and often correlates highly with deposition measures, making lichens an accurate, cost-effective tool for mapping and monitoring. Other groups of UNDP BANGLADESH / FLICKR organisms with high local biological diversity Air pollution is one of the most significant (e.g., insects and other arthropods) have high environmental health risks worldwide, responsible for potential as bioindicators because they have seven million deaths in 2012. Bronchial asthma and the capacity to provide more fine-grained chronic obstructive pulmonary disease are on the rise. information about the state of ecosystems; Cardiovascular disease, immune disorders, various they are also relatively easy to survey. Water cancers, and disorders of the eye, ear, nose and throat quality can be monitored through chemical are also affected by air pollution. Air pollution also analysis but long-term trends in freshwater affects biodiversity; it can reduce plant biodiversity ecosystems are perhaps better monitored and affect other ecosystem services, such as clean using the diversity of aquatic organisms (e.g., water and carbon storage. benthic invertebrates) as proxy for water quality and ecosystem health. 14. Ecosystems may affect air quality and have primarily beneficial outcomes for human health. Ecosystems affect air quality in three main ways: (1) Deposition – ecosystems directly remove air pollution, through absorption or intake of gases through leaves, and through direct deposition of particulate matters on plant surfaces; (2) Changes in meteorological patterns – as ecosystems affect local temperature, precipitation, air flows, etc., they also affect air quality and pollutant emissions. By altering climate and shading
4 Connecting Global Priorities: Biodiversity and Human Health BIODIVERSITY, FOOD control, nutrient cycling, erosion control and PRODUCTION AND NUTRITION water supply. 17. The loss of diversity from agro-ecosystems is increasing the vulnerability and reducing the sustainability of many production systems and has had negative effects on human health. While there have been significant increases in food production through the introduction of higher yielding uniform varieties and breeds, loss of genetic diversity in production systems through monocropping of uniform crop varieties or animal breeds has led to instances of large production losses and, in some cases, has had significantly negative health consequences. Loss of diversity has also resulted in the reduced provision of regulating and supporting ecosystem services, requiring additional chemical inputs and creating negative feedback loops.
18. The use of chemical inputs, particularly BIOVERSITY pesticides, has had severe negative Agricultural productivity has increased substantially consequences for wildlife, human health over the last 50 years yet some 800 million people and for agricultural biodiversity. While are food insecure. It is estimated that by 2050 food the control of disease vectors such as malaria production will have to feed over 9 billion people, many has generated health benefits, the use of of whom will be wealthier and demand more food with pesticides, especially in agriculture, has led proportionately more meat and dairy products that to serious environmental pollution, affected have greater ecological footprints. human health (25 million people per year suffer acute pesticide poisoning in developing Biodiversity underpins the productivity and resilience countries) and caused the death of many of agricultural and other ecosystems. However, land non-target animals, plants and fish. The use use change and agriculture are dominant causes of of agricultural biodiversity to help cope with biodiversity loss. pests and diseases and to increase soil quality is a win-win option which produces benefits to 16. Biodiversity in and around agricultural human health and to biodiversity. production systems makes essential contributions to food security and health. 19. Pollination is essential to food security Biodiversity is the source of the components generally and to the production of many of production (crops, livestock, farmed fish), of the most nutritious foods in particular. and the genetic diversity within these that Pollinators play a significant role in the ensures continuing improvements in food production of approximately one third of production, allows adaptation to current global food supply. Pollination also affects needs and ensures adaptability to future ones. the quantity, nutritional content, quality, and Agricultural biodiversity is also essential for variety of foods available. Global declines of agricultural production systems, underpinning pollinator species diversity and in numbers ecosystem services such as pollination, pest of pollinators have critical implications for
Connecting Global Priorities: Biodiversity and Human Health 5 food security, agricultural productivity and, Malnutrition is the single largest contributor to the global potentially, human nutrition. burden of disease affecting citizens of every country in the world from the least developed to the most. Two 20. Increasing sustainable production and billion people are estimated to be deficient in one or more meeting the challenges associated with micronutrients. At the same time, the consumption of climate change will require the increased poor-quality processed foods, together with low physical use of agricultural biodiversity. Climate activity, has contributed to the dramatic emergence of change is already having an impact the obesity and associated chronic diseases. nutritional quality and safety of food and increasing the vulnerability of food insecure individuals and households. The increased use of agricultural biodiversity will play an essential part in the adaptation and mitigation actions needed to cope with climate change and ensuring continued sustainable supplies of healthy food, providing adaptive capacity, diverse options to cope with future change and enhanced resilience in food production systems. B. VINCETI / BIOVERSITY
A diversity of species, varieties and breeds, as well as wild sources (fish, plants, bushmeat, insects and fungi) underpins dietary diversity and good nutrition. Variety-specific differences within staple crops can often be the difference between nutrient adequacy and nutrient deficiency in populations and individuals. Significant nutrient content differences in meat and milk among breeds of the same animal species have also been documented. Wildlife, from aquatic
S. PADULOSI / BIOVERSITY S. PADULOSI and terrestrial ecosystems, is a critical source of calories, protein and micronutrients like iron and 21. Agricultural practices, which make zinc for more than a billion people. Fish provide improved use of agricultural biodiversity, more than 3 billion people with important sources have been identified and are being used of protein, vitamins and minerals. around the world. Their potential value needs to be more widely recognized and their adoption 22. Access to wildlife in terrestrial, marine, more strongly supported through research and and freshwater systems is critical to support for appropriate policy and economic human nutrition, and global declines will regimes, including appropriate support to present major public health challenges for small-scale producers. Inter-disciplinary resource-dependent human populations, analysis and cross-sectoral collaboration particularly in low- and middle- income (among the agriculture, environment, health countries. Even a single portion of local and nutrition communities) is essential to traditional animal-source foods may result ensure the integration of biodiversity into in significantly increased clinical levels of policies, programmes and national and energy, protein, vitamin A, vitamin B6/B12, regional plans of action on food and nutrition vitamin D, vitamin E, riboflavin, iron, zinc, security. magnesium and fatty acids–thus reducing the risk of micronutrient deficiency. The use
6 Connecting Global Priorities: Biodiversity and Human Health of wild foods increases during the traditional nutrient deficiencies (e.g. vitamin A and ‘hungry season’ when crops are not yet ready iron), they cannot provide the full range of for harvest, and during times of unexpected nutrients needed. Food based approaches can household shocks such as crop failure or be supported by a greater focus on nutrition illness. However, wildlife populations are and biological diversity in agricultural, food in worldwide decline as a result of habitat system and value chain programs and policies destruction, over-exploitation, pollution and (compared to a dominant focus on a few staple invasive species. Conservation strategies can crops), including by promoting traditional therefore provide significant public health food systems and food cultures. dividends. 25. Some dietary patterns that offer substantial 23. The harvesting and trade of wild edible health benefits could also reduce climate plants and animals provides additional change and pressures on biodiversity. The benefits but also risks. The collection and global dietary transition towards diets higher trade of wild foods indirectly contributes to in refined sugars, refined fats, oils and meats, health and well-being by providing income for are increasing the environmental footprint household needs, particularly in less developed of the food system and also increasing the countries. Aggregating across numerous local incidence of type II diabetes, coronary heart level studies, estimates of the annual value of disease and other chronic non-communicable the bushmeat trade alone in west and central diseases. Some traditional diets, such as the Africa range between US$42 and 205 million Mediterranean diet, and alternative vegetarian (at 2000 values). This scale of economy poses or near-vegetarian diets, if widely adopted, important subsistence benefits. Hunting, would reduce global agricultural greenhouse butchering, consumption, global trade, and/ gas emissions, reduce land clearing and or contact in markets with other species can resultant species extinctions, and help prevent also presents risks of transmission and spread diet-related chronic non-communicable of infectious disease diseases.
MICROBIAL DIVERSITY AND NONCOMMUNICABLE DISEASES S. LANDERSZ / BIOVERSITY
24. Food based approaches are needed to help combat malnutrition and promote health. A healthy, balanced diet requires NIAID / FLICKR a variety of foods to supply the full range of nutrients needed (vitamins, minerals, Non-communicable diseases are becoming prevalent individual amino acids and fatty acids, and in all parts of the world. Some NCDs including other beneficial bioactive food components) autoimmune diseases, type 1 diabetes, multiple sclerosis, allergic disorders, eczema, asthma, While fortification and bio-fortification may inflammatory bowel diseases and Crohn’s disease may be cost-effective solutions to address specific
Connecting Global Priorities: Biodiversity and Human Health 7 be linked to depleted microbial diversity in the human 28. Several categories of organism with microbiome. which we co-evolved play a role in setting up the mechanisms that “police” and 26. Humans, like all complex plants and animals regulate the immune system. In addition have microbiota without which they could to the microbiota, some other organisms not survive. The human microbiome contains (the “Old Infections”) that caused persistent ten times more microorganisms than cells that infections or carrier states in hunter-gatherer comprise the human body. These occur inter communities were always present during alia on the skin, and in the gut, airways and human evolution, and so had to be tolerated by urogenital tracts. The biodiversity of bacteria, the immune system. Therefore they co-evolved viruses, fungi, archaea and protozoa of which roles in inducing the mechanisms that regulate microbes are comprised, and the interactions the immune system, terminate immune of microbes within the complex human activity when it is no longer needed, and block microbiome, influence both the physiology inappropriate attack on self (autoimmunity), of and susceptibility to disease and play an allergens (allergic disorders) or gut contents important role in the processes that link (inflammatory bowel disease). Some of these environmental changes and human health. immunoregulation-inducing organisms, The realization that humans are not merely for example a heavy load of helminths, can “individuals”, but rather complex ecosystems have detrimental effects on health, and so may be one of the major advances in our are eliminated by modern medicine in high- understanding of human health in recent income settings. This increases the importance years, with significant implications for both of the immunoregulatory role of microbiota ecology and human health. and the microbial environment in high-income settings, where these categories of organism 27. Environmental microbial ecosystems are need to compensate for loss of these “Old in constant dialogue and interchange Infections”. with the human symbiotic ecosystems. Microbes from the environment supplement 29. Reduced contact of people with the and diversify the composition of the symbiotic natural environment and biodiversity and microbial communities that we pick up biodiversity loss in the wider environment from mothers and family, which in turn leads to reduced diversity in the human play significant roles from a physiological microbiota, which itself can lead to immune perspective. Our physiological requirements dysfunction and disease. The immune for microbial biodiversity are evolutionarily system needs an input of microbial diversity determined. In addition to supplementation from the natural environment in order to of the symbiotic microbiota by organisms from establish the mechanisms that regulate it. the natural environment, the adaptability When this regulation fails there may be of the human microbiota (for example, to immune responses to forbidden targets such enable digestion of novel foods) depends as our own tissues (autoimmune diseases; upon acquiring organisms with the relevant type 1 diabetes, multiple sclerosis), harmless capabilities, or genes encoding necessary allergens and foods (allergic disorders, enzymes from the environment by horizontal eczema, asthma, hay fever) or gut contents gene transfer. Therefore, we need appropriate (inflammatory bowel diseases, ulcerative contact with potential sources of genetic colitis, Crohn’s disease). Urbanization and innovation and diversity, and our adaptability loss of access to green spaces are increasingly is threatened by loss of biodiversity in the gene discussed in relation to these NCDs. Half of reservoir of environmental microbes. the world’s population already lives in urban areas and this number is projected to increase markedly in the next half century, with the
8 Connecting Global Priorities: Biodiversity and Human Health most rapid increase in low- and middle- for deliberate modification and diversification income countries. Combined, these findings of the microbiota, which is emerging as an suggest an important opportunity for cross- exciting new approach to prevention and cure over between health promotion and education of many human diseases. on biodiversity. 32. Innovative design of cities and dwellings 30. Failing immunoregulatory mechanisms might be able to increase exposure to partly attributable to reduced contact the microbial biodiversity that our with the natural environment and physiological systems have evolved to biodiversity lead to poor control of expect. In high-income settings several very background inflammation. In high-income large studies reveal significant health benefits urban settings, there is often continuous of living near to green spaces. The benefits background inflammation even in the are greatest for people of low socioeconomic absence of a specific chronic inflammatory status. Recent data suggest that the effect is disorder. But persistently raised circulating not due primarily to exercise, and exposure levels of inflammatory mediators predispose to environmental microbial biodiversity is a to insulin resistance, metabolic syndrome, plausible explanation. This provides a strong type 2 diabetes, obesity, cardiovascular medical rationale for increased provision of disease and psychiatric disorders. Moreover, green spaces in modern cities. It might be in high-income settings several cancers sufficient to supplement a few large green rise in parallel with the increases in chronic spaces with multiple small green spaces that inflammatory disorders, because chronic deliver appropriate microbial diversity. inflammation drives mutation, and provides growth factors and mediators that stimulate 33. Considering “microbial diversity” as tumour vascularisation and metastasis. We an ecosystem service provider may need to maintain the microbial biodiversity contribute to bridging the chasm between of the environment in order to drive essential ecology and medicine/immunology, by regulation of the immune system. considering microbial diversity in public health and conservation strategies aimed 31. Understanding the factors that influence at maximizing services obtained from functional and compositional changes in ecosystems. The relationships our individual the human microbiome can contribute to bodies have with our microbiomes are a the development of therapies that address microcosm for the vital relationships our the gut microbiota and corresponding species shares with countless other organisms diseases. Disturbances in the composition with which we share the planet. and diversity of the gut microbiota are associated with a wide range of immunological, gastrointestinal, metabolic and psychiatric disorders. The required microbial diversity is obtained from the individual’s mother, from other people and from animals (farms, dogs) and the natural environment. The major influences on this diversity are antibiotics, diet, and diversity loss in the environment due to urbanisation and modern agricultural methods. We need to document the microbial biodiversity and the causes of diversity loss, preserve diversity, and identify the beneficial organisms and genes. These may be exploited
Connecting Global Priorities: Biodiversity and Human Health 9 INFECTIOUS DISEASES or distribution. Changes in land use and food production practices are among leading drivers of disease emergence in humans. At the same time, pathogen dynamics are changing. While pathogen evolution is a natural phenomenon, factors such as global travel, climate change, and use of antimicrobial agents are rapidly affecting pathogen movement, host ranges, and persistence and virulence. Beyond direct infection risks for human and animals, such changes also have implications for food CSIRO security and medicine. Infectious diseases cause over one billion human infections per year, with millions of deaths each year 36. Areas of high biodiversity may have high globally. Extensive health and financial burden is seen numbers of pathogens, yet biodiversity from both established and emerging infectious diseases. may serve as a protective factor for Infectious diseases also affect plants and animals, which preventing transmission, and maintaining may pose threats to agriculture and water supplies with ecosystems may help reduce exposure to additional impacts on human health. infectious agents. While the absolute number of pathogens may be high in areas of high 34. Pathogens play a complex role in biodiversity, disease transmission to humans biodiversity and health, with benefits in is highly determined by contact, and in some some contexts and threats to biodiversity cases, biodiversity may serve to protect against and human health in others. The pathogen exposure through host species relationships between infectious pathogens competition and other regulating functions. and host species are complex; disease and Limiting human activity in biodiverse habitats microbial composition can serve vital may reduce human exposure to high-risk regulating roles in one species or communities settings for zoonotic pathogens while serving while having detrimental effects on others. to protect biodiversity. Microbial dynamics, and their implications for biodiversity and health, are multifactorial; 37. Infectious diseases threaten wild species similarly, the role of biodiversity in pathogen as well as the people that depend on them. maintenance and not fully understood. The health burden of infectious diseases is not limited to humans and domestic 35. Human-caused changes in ecosystems, species; infectious diseases pose threat to such as modified landscapes, intensive biodiversity conservation as well. Pathogen agriculture, and antimicrobial use, are spill-over can occur from one wild species increasing infectious disease transmission to another, potentially causing an outbreak risks and impact. Approximately two- if the species or population is susceptible to thirds of known human infectious diseases the pathogen; similarly, diseases of domestic are shared with animals, and the majority animals and humans can also be infectious of recently emerging diseases are associated to wild species, as seen with the local with wildlife. Vector-borne diseases also extinctions of African Wild Dog populations account for a large share of endemic diseases. following the introduction of rabies virus Increasing anthropogenic activity is resulting from domestic dogs. Ebola virus has also in enhanced opportunities for contact at the been recognized as causing severe declines in human/animal/environment interface that great ape populations, including the critically- is facilitating disease spread, and through endangered wild lowland gorilla troops. Past changing vector abundance, composition, and/ Ebola outbreaks in great apes have preceded
10 Connecting Global Priorities: Biodiversity and Human Health human outbreaks, suggesting a sentinel Many of the diseases that afflicted or killed most or predictive value of wildlife monitoring people a century ago are today largely curable or to aid in early detection or prevention of preventable today thanks to medicines, many of which human infections. In addition to the direct are derived from biodiversity. Yet, in many instances, potential morbidity and mortality threats the very organisms that have given humanity vital from infectious diseases to the survival of insights into human diseases, or are the sources of wild populations, infection-related population human medications, are endangered with extinction declines may compromise health-benefitting because of human actions. ecosystem services that wildlife provide. For example, major declines recently seen from 39. Biodiversity has been an irreplaceable fungal infections associated with White Nose resource for the discovery of medicines Syndrome in North American bats and chytrid and biomedical breakthroughs that have in amphibians may affect the pest control alleviated human suffering. Drugs derived functions that these animals provide. from natural products may perhaps be the most direct and concrete bond that many 38. The rapidly growing number of invasive may find between biodiversity and medicine. species cause significant impacts on human Among the breakthroughs that dramatically health, and this effect is expected to further improved human health in the twentieth increase in the future, due to synergistic century, antibiotics rank near the top. The effects of biological invasions and climate penicillins as well as nine of the thirteen change. Preventing and mitigating biological other major classes of antibiotics in use, invasions is not only is important to protecting derive from microorganisms. Between 1981 biodiversity, but can also protect human health. and 2010, 75% (78 of 104) of antibacterials Through trade and travel, the number of invasive newly approved by the USFDA can be traced species is increasing globally as a consequence back to natural product origins. Percentages of the globalization of the economies, and the of antivirals and antiparasitics derived from increase is expected to intensify in the future natural products approved during that same due to synergistic effects with climate change. period are similar or higher. Reliance upon Invasive species not only impact biodiversity, biodiversity for new drugs continues to this but also affect human health causing diseases or day in nearly every domain of medicine. infections, exposing humans to bites and stings, causing allergic reactions, and facilitating the 40. For many of the most challenging health spread of pathogens. problems facing humanity today, we look to biodiversity for new treatments or insights into their cures. Most of the medicinal MEDICINES: THE CONTRIBUTION potential of nature potential has yet to be OF BIODIVERSITY TO tapped. Plants have been the single greatest THE DEVELOPMENT OF source of natural product drugs to date, and PHARMACEUTICALS although an estimated 400,000 plant species populate the earth, only a fraction of these have been studied for pharmacologic potential. One of the largest plant specimen banks, the natural products repository at the National Cancer Institute, contains ~60,000 specimens, for instance. Other realms of the living world, especially the microbial and marine, are only beginning to be studied and hold vast potential for new drugs given both their diversity and the medicines already discovered from them.
GENEVIÈVE ANDERSON Many species, potential sources of medicines are threatened by extinction.
Connecting Global Priorities: Biodiversity and Human Health 11 41. Greater even than what individual species contexts. Some traditional medical systems offer to medicine through molecules are codified, and some even institutionalized. they contain or traits they possess, an They range from highly developed ways of understanding of biodiversity and ecology perception and understanding, classification yield irreplaceable insights into how life systems (local-taxonomies) to metaphysical works that bear upon current epidemic precepts. Links to geography, community, diseases. Consider the multiple pandemics worldviews, biodiversity and ecosystems based that have resulted from antibiotic resistance. on specific epistemologies make traditional Human medicine tends to use a paradigm for health practices diverse and unique. By treating infections unknown in nature which extension, level of expertise is heterogeneous is treating one pathogen with one antibiotic. and therefore internal validation methods Most multicellular life (and a good share of differ substantially despite an underlying single cellular life) produces compounds with philosophical principle of interconnectedness antibiotic properties but never uses them in of social and natural worlds. isolation. Infections are attacked, or more often prevented, through the secretion of 43. Medicinal and aromatic plants, the great several compounds at once. majority of which are sourced from the wild, are used in traditional medicine and also in the pharmaceutical, cosmetic and TRADITIONAL MEDICINE food industries. The global use and trade in medicinal plants and other biological resources, including wildlife, is high and growing. Plants used in traditional medicine are not only important in local health care, but are important to innovations in healthcare and associated international trade; they enter various commodity chains based on information gathered from their use in traditional medical pharmacopeia. Globally, an estimated 60,000 species are used for their medicinal, nutritional and aromatic
C. KRESTCH properties, and every year more than 500,000 Millions of people rely on traditional medicine tons of material from such species are traded. that is dependent on biological resources, well It is estimated that the global trade in plants functioning ecosystems and on the associated context for medicinal purposes reaches a value of over specific knowledge of local health practitioners. In 2,5 billion USD and is increasingly driven by local communities, health practitioners trained in industry demand. traditional and non–formal systems of medicine often 44. Threats to medicinal plants, animals and play a crucial role in linking health-related knowledge other medicinal resources are increasing. to affordable healthcare delivery. Wild plant populations are declining- one in 42. Traditional medical knowledge spans five species is estimated to be threatened with various dimensions relating to medicines, extinction in the wild. Animals (amphibians, food and nutrition, rituals, daily routines reptiles, birds, mammals) used for food and and customs. There is no single approach to medicine are more threatened than those traditional medical knowledge. Traditional not used. Overharvesting, habitat alteration, knowledge is not restricted to any and climate change are among major drivers particular period in time, and constantly of declines in commercially important wild undergoes re-evaluation based on local plant resources used for food and medicinal
12 Connecting Global Priorities: Biodiversity and Human Health purposes. These pose a threat both to the wild and promote existing tools, databases and species and to the livelihoods of collectors, registers and intellectual property rights that who often belong to the poorest social groups. are sensitive to community values. There is a clear need to continue efforts at developing assessment methods and indicators 47. Improving public health outcomes and for conservation and sustainable use. achieving objectives of ‘Health for All’ and ‘Good Health at Low Cost’ should 45. Sustainable use of medicinal resources can include traditional medical care and the provide multiple benefits to biodiversity, development of appropriate integrative livelihoods and human health, in methodologies and safety standards particular, relating to their affordability, within and across medical systems. More accessibility and cultural acceptability. than one-third of the population in many Sustainable medicinal resource management developing countries do not have access to for both captive-breeding and wild-collection modern healthcare, and are dependent on is crucial for the future of traditional medicine, traditional medical systems. There is a high that involves all stakeholders including patronage of and dependence on traditional conservationists, private healthcare sector, health practitioners to provide care to people medical practitioners and its consumers. with inadequate access to modern health Appropriate market-based instruments to infrastructure or with a preference for enable sustainable and responsible utilization traditional systems. Pluralistic approaches of resources in traditional medicine are that integrate natural resources and medical required. Value chains of traditional medicines knowledge and are sensitive to local priorities can be simple and local or global and extremely and contexts can enable better health complex. Some resources have one or a few outcomes. This implies the need to develop specific uses while others are used in many cross-sectoral, cost-effective measures to different products and markets. In many cases test safety, efficacy and quality of traditional the people who harvest these resources have medicines, the integration of traditional little knowledge of the subsequent uses and healers in the healthcare system through values. Ensuring equitable economic returns appropriate accreditation practices and to local communities by promoting value processes, cross-learning between different added activities at the local level could help to knowledge systems and disciplines through harness the knowledge of local communities participatory, formal and informal learning on medicinal resources and promote their processes to supplement current practices in sustainable use. a culturally sensitive way.
46. Sui generis models may need to be developed and applied to secure rights of BIODIVERSITY AND MENTAL, indigenous peoples and local communities PHYSICAL AND CULTURAL WELL- over traditional medical knowledge and BEING related resources. Traditional medical It is well established that biodiversity is a central knowledge is often an inspiration for component of many cultures and cultural traditions, industrial R&D processes in bio-resource and evidence that exposure to nature and more based sectors, necessitating mechanisms to biodiverse environments can also provide mental secure appropriate attribution and sharing of and physical health benefits. Over half of the world’s rights and benefits with knowledge holders, population lives in cities and that proportion is as set out in the Nagoya Protocol on Access increasing. There is a rising trend for people, especially to genetic resources and equitable sharing from poor communities, to be separated from nature of benefits arising from their commercial and be deprived of the physical, physiological and utilization. It would be beneficial to strengthen psychological benefits that nature provides.
Connecting Global Priorities: Biodiversity and Human Health 13 4Connecting Global Priorities: Biodiversity and Human Health 14
GLEN BOWES 49. 48. inclu – nature with interaction The exposure to microbial diversity. research Other impacts have beenassociated withgreater mentalhealth and stress. Similarlybeneficial for mentalillnessessuchasdepression, anxiety andthatothers, therelationship isstrongest diseasesthan lower overall incidence ofcertain to fewer green space symptoms report anda that have adultsexposed countries suggested Some studiesofpopulations indeveloped for women. of disabilityworldwide,particularly causes disease andisamongthelargestsingle accounts for burden 4.3% oftheglobal of onmentalhealth. impacts toExposure green space may have positive people. or theactionsofother perceived threats from isolation, wildanimals owingtohabitats (woodlandandwetland) naturalare ofspendingtimeincertain fearful thosefromchildren, urbanareas, particularly hand, someresearch that some hassuggested fears/ societal for childsafety. theother On andparental of increased useoftechnology in thetimespentplaying outdoors asaresult a “nature-deficit disorder”, dueto areduction increasingly sufferin developed countries from Conversely, ithasbeenstipulated that children nature themselvesasadults. likely to conserve may bemore ofconservation importance aboutthenaturalknowledge worldandthe andchildren whogrowdevelopment, upwith to toExposure nature childhood isimportant forproblems, including children. for depression, anxiety, andbehavioural settings –may contribute to treatments andwildanimalsin domestic animals, Depression ding
50. toAccess natural green spacecanincrease 51. isoften centralBiodiversity to cultures, enhancing physical fully fitnessisstillnot that green space canoffer for promoting and thepotential patients andresidents. While, andvulnerable physical activityinsedentary including wildlife-rich gardens, canalsoboost to developbiodiversesettings, spaces. Efforts biodiversity encourages useofurbangreen in green spaces. isevidence There that enhanced exposure to environmental microbes may to bemore attributable significantly that healthbenefits hasalsobeensuggested It physical activityandimprove life expectancy. urban environment canencourage regular of largecities,access to green spaces inthe thoseinpoorer inner-urban areasparticularly islimited, which access to opencountryside for populations Among and independence. andfacilitatehealth benefits, connections social may alsoprovideimmune function.It mental communicable diseases,aswellimproved may ofseveral includereduced risk non- for ofphysical health.Thebenefits activity withbenefitslevels ofphysical activity outcomes inhospitalpatients.recovery reduce recuperation timesandimprove has indicated ofnature that experience can landscapes influence forms of music, language, landscapes influence language, forms ofmusic, and environmental policies. environments) publichealth withintourism, andaquatic (terrestrial blue infrastructure” to promotecountries andenhance “green and thererecognised, isagrowing interest inmany being. Species,habitats, ecosystems, and cultural traditions andcultural well-
B. SHAPIT / BIOVERSITY art, literature and dance. They form essential IMPACTS OF PHARMACEUTICAL elements of food production systems, PRODUCTS ON BIODIVERSITY AND culinary traditions, traditional medicine, rituals, worldviews, attachments to place and CONSEQUENCES FOR HEALTH community, and social systems. Use of the Antibiotics and other pharmaceuticals are essential WHO Quality Of Life Assessment (devised to for human health and also play an important role determine an individual’s quality of life in the in veterinary medicine. However, the release context of their culture and value systems) has of active pharmaceutical ingredients into the shown that the environmental domain is an environment can be harmful to biodiversity, with important part of the quality of life concept. negative consequences for human health. Socio-ecological production landscapes (e.g. Satoyama in Japan) or conservation systems 54. The release of pharmaceuticals and (e.g. sacred groves, ceremonial sites) or Active Pharmaceutical Ingredients therapeutic landscapes (e.g. sacred healing (APIs) into the environment can have an sites), and related traditional knowledge impact on biodiversity, ecosystems and practices can have therapeutic value and ecosystem service delivery, and, may, in contribute to health and well-being. turn negatively impact human health. A range of pharmaceuticals, including 52. Significant changes to local biodiversity or hormones, antibiotics, anti-depressants ecosystem sustainability can have specific and antifungal agents have been detected in and unique impacts on local community rivers and streams across the world. Most health where the physical health of a pharmaceuticals are designed to interact with community is directly influenced by or a target (such as a specific receptor, enzyme, dependent upon ecosystem services, or biological process) in humans and animals particularly regarding access to diverse to deliver the desired therapeutic effect. If food and medicinal species. Indigenous and these targets are present in organisms in local communities often act as stewards of local the natural environment, exposure to some living natural resources based on generations of pharmaceuticals might be able to elicit effects accumulated traditional knowledge, including in those organisms. Pharmaceuticals can also knowledge of agricultural biodiversity, cause side effects in humans and it is possible and biodiversity that supports traditional that these and other side effects can also occur medicinal knowledge. Where local traditions in organisms in the environment. During the and cultural identity are closely associated life cycle of a pharmaceutical product, APIs with biodiversity and ecosystem services, may be released to the natural environment, declines in the availability and abundance of including during the manufacturing process such resources can have a detrimental impact via human or domestic animal excretion on community well-being, with implications into sewage systems, surface water or soils, for mental and physical health, social welfare when contaminated sewage sludge, sewage and community cohesion. effluent or animal manure is applied to land. APIs may also be released into the soil 53. While many community-specific links environment when contaminated sewage between health, culture and biodiversity sludge, sewage effluent or animal manure is have been documented and measured, applied to land. Veterinary pharmaceuticals much of the evidence for a more universal may also be excreted directly to soils by pasture relationship is relatively sparse beyond animals. Measures are needed to reduce this anecdotal accounts. However, there is environmental contamination. growing recognition of the role of biodiversity and ecosystem services in shaping broad 55. Antibiotic and antimicrobial use can perspectives of quality of life. alter the composition and function of the
Connecting Global Priorities: Biodiversity and Human Health 15 human microbiome and limiting their use perspective, the use of antimicrobials and would provide biodiversity and health antibiotics may disrupt microbial composition, co-benefits. Antibiotic use can dramatically including the relationships between hosts and alter the composition and function of the their symbiotic microbes, and lead to diseases. human microbiome. Although much of the At the same time, antibiotic resistance in microbiome and its relationship to its host any environment can pose serious threats remains unexplored, already apparent is that to public health. Aside from its potential to changes to the variety and abundance of cultivate resistance, antibiotic use also carries various microorganisms, as can occur with the potential to disrupt symbiotic bacterial antibiotic use, may affect everything from composition. the host’s weight and the risk of contracting autoimmune disease, to susceptibility to 57. Endocrine disrupting chemicals found in infections. The microbiome may also be able pharmaceuticals products and also in many to affect mood and behaviour. The use of household, food and consumer products antibacterial products and antibiotics may have adverse effects on the health of also be linked to the increase in chronic terrestrial, freshwater and marine wildlife inflammatory disorders, including allergies and human health. The use of contraceptive such as asthma and eczema, because they hormones and veterinary growth hormones reduce exposure to microbial agents that set up have been linked to endocrine disruption the regulation of the immune system. Limiting and reproductive dysfunction in wildlife. the use of antimicrobial agents could provide They also affect both male and female human potential co-benefits for human health and reproduction, and have been linked to prostate biodiversity, reducing chronic inflammatory cancer, neurological, endocrinological, diseases through a healthy and more diverse thyroid, obesity, and cardiovascular problems. human microbiota while also reducing the risk Biodiversity has also been a good monitor for of emerging disease from antibiotic-resistant some of these human health problems. In strains and the potential impacts of antibiotics some cases, health specialists were alerted on ecosystems more broadly. to the scale of a potential problem through changes originally recorded in wild fish 56. The inappropriate use of antibiotics in populations. plants, animals, and humans has cultivated numerous highly resistant bacterial 58. The inappropriate use of some non- strains. In some instances, resistant bacterial steroidal anti-inflammatory drugs and strains cannot be effectively treated with any other veterinary drugs threatens wildlife currently available antibiotic. Promoting the populations. For example, in the 1980s, responsible and prudent use of antibiotics and populations of three previously abundant antimicrobials in human health, agricultural vulture species in South Asia were reduced to practices and food production systems near extinction due to the use in livestock of can achieve public health and biodiversity diclofenac, residues of which remained in the co-benefits. Poorly managed industrial carcasses of treated animals. This led to negative agricultural practices contribute to ecosystem impacts on human health through spread of degradation, air and water pollution and soil diseases by feral dogs as access to carcasses depletion and rely heavily on the inappropriate increased, especially among communities use of antibiotics for both therapeutic as well who rely on vultures to consume their dead. as prophylactic (growth promotion) use, which Following bans on the use of diclofenac and its may lead to environmental dispersion of replacement by meloxicam, vulture population antimicrobial agents, antibiotic resistance, and declines have slowed and some show signs of reduced efficacy in subsequent use for medical recovery in the region. Without proper risk or food production applications. From a health assessment and regulation the marketing and
16 Connecting Global Priorities: Biodiversity and Human Health use of pharmaceuticals used for livestock may there would be increased productivity at high continue to pose threats to human and wildlife latitudes there will be decreased productivity health. at low/mid latitudes, affecting poor developing countries.
GLOBAL CHANGE ADAPTATION TO 61. Disasters may be precipitated by impacts CLIMATE CHANGE AND DISASTER on critical ecosystems or the collapse of RISK REDUCTION essential ecosystem services. Disasters may include disease epidemics, flooding, storm, extreme weather, and wildfires. Some of these may be precipitated by ecosystem disruption. There is an increase in frequency and intensity of some climate-related extreme events. Ecosystem degradation can increase the vulnerability of human populations to such disasters. New environmental impacts often occur during and after an emergency AIRMAN 1ST CLASS CHERYL SANZI (USAF) AIRMAN 1ST CLASS CHERYL with an increased demand for certain natural 59. Climate change is already negatively resources which can place additional stress impacting on human health and these on specific ecosystems (such as groundwater impacts are expected to intensify. Direct resources) and their functioning. effects of climate change on health may include stroke and dehydration associated 62. Competition over access to ecosystem with heat waves (in particular in urban areas), goods and services can contribute to, negative health consequences associated with and become a cause of, conflict, with reduced air quality and the spread of allergens consequences that can negatively impact Effects are also mediated through the impacts ecosystem goods and services in both the on ecosystems and biodiversity. Such effects short- and long-term. Greater recognition may include decreased food production and needs to be given to the potential positive role changes in the spread of climate-sensitive that conservation and ecosystem management waterborne and water-related, food-borne can play in conflict prevention and resolution and vector-borne diseases. There may be and peace building, while the converse also synergistic effects of climate change, land use holds. change, pollution invasive species and other drivers of change which can amplify impacts 63. The creation of disaster-resilient societies on both health and biodiversity. is increasingly tied to and dependent upon resilience in ecosystems, and sustainability 60. Climate change will not only affect and security in the flow and delivery of agricultural production systems but also essential ecosystem goods and services the nutritional content of foods and the – not only those directly associated with distribution and availability of fisheries. resilience to immediate disaster impacts, but Changes in temperature and precipitation also those that normally support communities patterns will have complex effects, but the and wider society. Long-term health status is net effect on food production will be negative. an important indicator of the resilience of While rising levels of atmospheric carbon, a community – as a marker for capacity to tend to increase productivity, they will lead overcome or adapt to health challenges and to reduced concentrations of minerals such other social, environmental and economic as zinc and iron in crops such as wheat and pressures. Communities whose ability to rice. With regard to marine fisheries, while overcome current challenges are affected by
Connecting Global Priorities: Biodiversity and Human Health 17 ecosystem degradation at the time of a disaster efficiency, including a decarbonization of event – natural or man-made – are likely to be energy supplies this century. These changes significantly more vulnerable to disasters than will need to be complemented by increased communities with greater ecological security. equality in access to and use of energy and other natural resources. 64. Biodiversity helps to improve resilience of ecosystems, contributing to adaptation to 66. Alternative scenarios to 2050, as well as climate change and moderating the impacts practical experience, demonstrate that it is of disasters. Ecosystem-based adaptation and possible to secure food security and reduce mitigation strategies are needed to build the poverty while also protecting biodiversity resilience of managed landscapes and jointly and addressing climate change and attain reduce the vulnerabilities of ecosystems and other human development goals, but that communities reliant upon them for their this requires transformational change. health, livelihoods and well-being. For example, Scenario analyses show that there are multiple Ecosystem-based approaches to flood-plain plausible pathways to simultaneously achieve and coastal development can reduce human globally agreed goals. Common elements of exposure to risks from flooding. Coral reefs these pathways include: reducing greenhouse are very effective in protecting against coastal gas emissions from energy and industry; hazards (reducing wave energy by 97%) and increasing agricultural productivity and protect over 100 million people in this way containing agricultural expansion to prevent from coastal storm surges. The conservation further biodiversity loss and to avoid excessive and use of genetic resources in agriculture, greenhouse gas emissions from conversion aquaculture and forestry is important to of natural habitats; restoring degraded allow crops, trees, fish and livestock to adapt land, protecting critical habitats; managing to climate change. biodiversity in agricultural landscapes; reducing nutrient and pesticide pollution and water use; SUSTAINABLE CONSUMPTION AND reducing post harvest losses in agriculture and food waste by retailers and consumers PRODUCTION as well as moderating the increase in meat 65. Increased pressure on the biosphere, driven consumption. Implementing these measures by increasing human populations and per requires a package of actions including legal capita consumption threatens biodiversity and policy frameworks, economic incentives, and human health. Biosphere integrity and public and stakeholder engagement. is threatened by a number of interacting Coherence of policies and coordination across drivers including climate change, land-use sectors are essential. change, pollution and biodiversity loss. Global population is projected to increase to nine 67. Behavioural change is needed to improve to ten billion by 2050, and may continue to human health and protect biodiversity. increase this century. Greater investment in Human behaviour, which is informed by education of girls and women and improved differences in knowledge, values, social norms, access to contraceptives information and power relationships, and practices is at the services can improve human health and core of the interlinkages between health and well-being directly and also help to slow biodiversity, including challenges related to these trends, potentially reducing pressures food, water, disease, medicine, physical and on ecosystems. Under business as usual mental well-being, adaptation and mitigation scenarios, increased per-capita consumption of climate change. There is a need to draw will lead to even greater increased pressures on upon the social sciences to motivate choices the biosphere. Slowing these trends requires consistent with health and biodiversity improvements in energy and resource use objectives and to develop new approaches
18 Connecting Global Priorities: Biodiversity and Human Health through, inter alia, better understanding c. Addressing drivers of environmental change of behavioural change, production and (deforestation and other ecosystem loss and consumption patterns, policy development, degradation and chemical pollution) that and the use of non-market tools. The need harm both biodiversity and human health, for more effective communication, education including direct health impacts and those and public awareness to be spread more widely mediated by biodiversity loss; through school systems and other channels and to devise communication and awareness d. Promoting lifestyles that might contribute strategies on biodiversity and health. jointly to positive health and biodiversity outcomes (for example, protecting traditional foods and food cultures, STRATEGIES FOR HEALTH AND promoting dietary diversity) BIODIVERSITY Addressing the unintended negative impacts 68. Health and biodiversity strategies could be e. of health interventions on biodiversity developed with the aim of ensuring that (for example, antibiotic resistance, the biodiversity and health linkages are contamination from pharmaceuticals), and widely recognized, valued, and reflected incorporating ecosystem concerns into in national public health and biodiversity public health policies. strategies, and in the programs, plans, and strategies of other relevant sectors, with f. Addressing the unintended negative impacts the involvement of local communities. The of biodiversity interventions on health (for implementation of such strategies could be example, effect of protected areas or hunting a joint responsibility of ministries of health, bans on access to food, medicinal plants). environment, and other relevant ministries responsible for the implementation of g. Adopting the One Health approach or environmental health programs and national other integrative approaches that consider biodiversity strategies and action plans. Such connections between human, animal, strategies would need to be tailored to the and plant diseases and promotes cross- needs and priorities of particular countries. disciplinary synergies for health and Such strategies might include the following biodiversity. objectives: h. Educating, engaging and mobilizing the a. Promoting the health benefits provided by public and the health sector, including biodiversity for food security and nutrition, professional health associations as water supply, and other ecosystem services, potential, powerful advocates for the pharmaceuticals and traditional medicines, sustainable management of ecosystems. mental health and physical and cultural Mobilize organizations and individuals well-being. In turn, this provides a rationale who can articulate the linkage and the for the conservation and sustainable use of enormous value proposition investments biodiversity as well as the fair and equitable in sustainable ecosystem management sharing of benefits; provide to the social and economic health of communities; b. Managing ecosystems to reduce the risks of infectious diseases, including zoonotic i. Monitoring, evaluating and forecasting and vector-borne diseases, for example by progress toward the achievement of avoiding ecosystem degradation, preventing national, regional and global targets at invasive alien species, and limiting or regular intervals against evidence-based controlling human-wildlife contact; indicators, including threshold values for critical ecosystem services, such as the
Connecting Global Priorities: Biodiversity and Human Health 19 availability and access to food, water and computerized modeling programs should medicines. also consider health-biodiversity linkages to manage future risks and safeguard ecosystem TOOLS, METRICS AND FURTHER functioning while ensuring that social costs, including health impacts, associated with RESEARCH new measures and strategies do not outweigh 69. Integration of biodiversity and human potential benefits; health concerns will require the use of common metrics and frameworks. 71. The development of precautionary policies Conventional measures of health are often that place a value on ecosystem services to too limited in focus to adequately encompass health, and make positive use of linkages the health benefits from biodiversity. between biodiversity and health are Notwithstanding the broad WHO definition needed. For example, for integrated disease of health, traditional measures of health, surveillance in wildlife, livestock and human such as disability adjusted life years (DALYs) populations as a cost-effective measure to and burden of disease, tend to have a more promote early detection and avoid the much narrow focus on morbidity, mortality and greater damage and costs of disease outbreaks; disability, and fail to capture the full breadth 72. Measuring health effects of ecosystem of complex linkages between biodiversity and change considering established “exposure” health. Alternative metrics defining health are threshold values helps highlight needed to reflect the broad aspects of human biodiversity-health-development linkages. health and well-being. Further, to increase Mechanisms linking ecosystem change to collaboration across disciplines and sectors health effects are varied. For many sub-fields, more attention could be paid to “translating” exposure thresholds or standards have been the meaning of key metrics to increase scientifically established that serve as trigger shared relevance. Similarly, frameworks points for taking action to avoid or minimize provide a conceptual structure to build on disease or disability. For example, air quality for research, demonstration projects, policy standards exist for particle pollution, WHO and other purposes. Embracing a broad has established minimum quantities of per framework that aims to maximize the health capita water required to meet basic needs, of ecosystems and humans both could help the and thresholds for food security define the different disciplines and sectors work more quantity of food required to meet individual collaboratively. The conceptual framework of daily nutritional needs. Measuring the the IPBES, building upon that articulated in health effects of ecosystem change relative the Millennium Ecosystem Assessment, is a to established threshold values highlights framework that links biodiversity to human how such change constitutes exposure – an well-being, considering also institutions and important principle linking cause and disease drivers of change. or other health effects –and encourages action 70. The development of comparable tools–and if thresholds are exceeded maximizing the use of existing tools– 73. Economic valuation approaches linking to promote a common evidence base ecosystem functioning and health that across sectors is needed. Tools ranging support decisions about resource allocation from systematic assessment processes (for may appeal to a variety of stakeholders. example, environmental impact assessments, Many approaches enhance understanding strategic environmental assessments, risk of ecosystem functioning and human health assessments, and health impact assessments) linkages. Common on the health side are to the systematic reviews of research findings, environmental hazard or risk factor analyses. to standardized data collection forms to
20 Connecting Global Priorities: Biodiversity and Human Health Others include identifying and reducing into Goals on food security and nutrition, health disparities/inequities; focusing water and health. The SDG framework should on environmental and socio-economic also provide for the enabling conditions for determinants of disease, and conducting human health and for the conservation and health impact assessments. Conservation sustainable use of biodiversity, and for the approaches include land-/seascape change underlying drivers of both biodiversity loss and modelling, vulnerability and adaptation ill-health to be addressed. This implies Goals assessments, linked health and environmental for improved governance, and institutions, at assessments and ecosystem service analyses. appropriate scales (from local to global), for the management of risks and the negotiation 74. Further research is needed to elucidate of trade-offs among stakeholder groups, where some of the potential knowledge gaps on they exist, as well as for behavioural change. linkages between biodiversity and human health. Examples of key questions include: 76. Ongoing evaluation of synergistic and a. What are the relationships between antagonistic effects of complementary biodiversity, biodiversity change and sustainable development goals and infectious diseases? Specifically, what are targets is needed. This includes sustainable the effects of species diversity, disturbance development goals and targets addressing and human-wildlife contacts? What are the health, food and freshwater security, climate implications for spatial planning? change and biodiversity loss and evaluate the long-term impacts of trade-offs is needed; b. What are the linkages between biodiversity such as the trade-off and short-term gains (including biodiversity in the food from intensive and unsustainable agricultural production system), dietary diversity and production, against longer-term nutritional health? Is there a relationship between security. For example, the impacts of dietary biodiversity and the composition and unsustainable agricultural practices that may diversity of the human microbiome? What exacerbate climatic pressures may also lead are good indicators of dietary biodiversity? to greater food insecurity, particularly among What are the cumulative health impacts of poor and vulnerable populations, by negatively ecosystem alteration? influencing its availability, accessibility, utilization and sustainability. THE SUSTAINABLE DEVELOPMENT 77. Health is our most basic human right GOALS AND POST-2015 and therefore one of the most important SUSTAINABLE DEVELOPMENT indicators of sustainable development. AGENDA At the same time, the conservation and sustainable use of biodiversity is 75. Health and biodiversity, and the linkages imperative for the continued functioning among them and with other elements of ecosystems at all scales, and for the of sustainable development must be delivery of ecosystem services that are well integrated into the post-2015 essential for human health. There are many developmentw agenda. The post-2015 opportunities for synergistic approaches that development agenda provides a unique promote both biodiversity conservation and opportunity to advance the parallel goals the health of humans. However, in some of improving human health and protecting cases there must be trade-offs among these biodiversity. The Sustainable Development objectives. Indeed, because of the complexity Goals will address various aspects of human of interactions among the components well-being and be accompanied by targets of biodiversity at various tropical levels and indicators. Specific biodiversity related (including parasites and symbionts), and targets and indicators should be integrated
Connecting Global Priorities: Biodiversity and Human Health 21 across ecosystems at various scales (from of health–biodiversity relationships will allow the planetary-scale biomes to human- for the adjustment of interventions in both microbial interactions), positive, negative sectors, with a view to promoting human well- and neutral links are quite likely to occur being over the long-term. simultaneously. An enhanced understanding
22 Connecting Global Priorities: Biodiversity and Human Health ISTOCKPHOTO PART I Concepts, Themes & Directions 1. Introduction to the State of
CONOR KRETSCH Knowledge Review
The right to health is well established as a The dual challenges of biodiversity loss and rising fundamental right of every human being.¹ global health burdens are not only multifaceted Biodiversity is at the heart of the intricate web and complex; they also transcend sectoral, of life on earth and the processes essential to its disciplinary and cultural boundaries, and demand survival. Our planet’s biological resources are not far-reaching, coherent and collaborative solutions. only shaped by natural evolutionary processes but One of the widely acknowledged shortcomings are also increasingly transformed by anthropogenic of the Millennium Development Goals (MDGs) activity, population pressures and globalizing and targets (the precursors of the SDGs) was the tendencies. When human activity threatens these lack of cross-sectoral integration among social, resources, or the complex ecosystems of which economic and environmental goals, targets and they are a part, it poses potential risks to millions priorities (Haines et al. 2012). Opposing trends of people whose livelihoods, health and well-being have been reported among the key indicators are sustained by them. The increasingly complex for the MDGs, with many negative trends for global health challenges that we face, including environmental indicators, including biodiversity poverty, malnutrition, infectious diseases and (CBD 2014; Haines et al. 2012; WHO 2015). the growing burden of noncommunicable diseases (NCDs), are more intimately tied than ever to The World Health Organization (WHO) and the complex interactions between ecosystems, the Secretariat of the Convention on Biological people and socioeconomic processes. These Diversity (CBD) are working together to address considerations are also at the heart of the post- these challenges.² This State of Knowledge Review 2015 Development Agenda and the Sustainable assembles expertise and insights from numerous Development Goals (SDGs). researchers, practitioners, policy-makers
¹ The right to health is established as a fundamental right of every human being in Article 1 of the World Health Organization Constitution (http://www.who.int/governance/eb/who_constitution_en.pdf). This was the first international instrument to enshrine the “right to health” as the “enjoyment of the highest attainable standard of health”, also reflected in the Universal Declaration of Human Rights in 1948. The right to health is understood as an inclusive right that extends beyond health care to include the underlying determinants of health, such as access to water and food, essential medicines, etc. ² The World Health Organization and the Convention on Biological Diversity have been cooperating to promote greater awareness about, and action on, the interlinkages between human health and biodiversity by convening experts from relevant organizations, joint publications and organizing regional capacity-building workshops for experts from the biodiversity and health sectors in the Americas and Africa (Romanelli et al. 2014). The Conference of the Parties to the Convention on Biological Diversity has adopted a number of decisions in this regard (CBD 2010, 2012, 2014).
24 Connecting Global Priorities: Biodiversity and Human Health and experts from the fields of biodiversity the evolving context of the SDGs and post-2015 conservation, public health, agriculture, nutrition, Development Agenda, as well as the Strategic Plan epidemiology, immunology, and others to do the for Biodiversity 2011–2020 (see Box 1); following: • Facilitate cross-sectoral, interdisciplinary • Provide an overview of the scientific evidence and transdisciplinary approaches to health for linkages between biodiversity and human and biodiversity conservation, and promote health in a number of key thematic areas; cooperation between different sectors and actors in an effort to mainstream biodiversity in national • Contribute to a broader understanding of the health strategies and mainstream health in importance of biodiversity to human health in biodiversity strategies;
Box 1: Strategic Plan for Biodiversity 2011–2020
The Strategic Plan for Biodiversity 2011–2020 and its twenty Aichi Targets provide an agreed overarching framework for action on biodiversity, and a foundation for sustainable development for all stakeholders, including agencies across the United Nations (UN) system. The Strategic Plan was adopted at the tenth meeting of the Conference of the Parties to the Convention on Biological Diversity and has been recognized or supported by the governing bodies of other biodiversity-related conventions, including the Convention on International Trade in Endangered Species of Wild Fauna and Flora, the Convention on the Conservation of Migratory Species of Wild Animals, the Convention on Wetlands of International Importance, the International Treaty on Plant Genetic Resources for Food and Agriculture, the World Heritage Convention, as well as the UN General Assembly.
Governments at Rio 20 a rmed the importance of the Strategic Plan for Biodiversity 2011–2020 and achieving the Aichi Biodiversity Targets, emphasizing the role that the Strategic Plan plays for the UN system, the international community and civil society worldwide to achieve the world we want. It is primarily implemented by countries through national biodiversity strategies and action plans, with Parties encouraged to set their own national targets within the framework of the Aichi Biodiversity Targets. The UN General Assembly has encouraged Parties and all stakeholders, institutions and organizations concerned to consider the Strategic Plan for Biodiversity 2011–2020 and the Aichi Biodiversity Targets in the elaboration of the post-2015 UN Development Agenda, taking into account the three dimensions of sustainable development.
The Strategic Plan for Biodiversity 2011–2020 includes a vision for 2050, ve strategic goals and twenty Aichi Biodiversity Targets, mostly to be achieved by 2020. The 2050 Vision stresses the role of biodiversity for human well-being: “biodiversity to be valued, conserved, restored and wisely used, maintaining ecosystem services, sustaining a healthy planet and delivering bene ts essential for all people . The ve goals include: to protect nature (Goal C), to maximize the bene ts for all people (Goal D), to reduce pressures on biodiversity (Goal B), to address the underlying causes of loss (Goal A), and to provide for enabling activities (Goal E). Under Goal D, Target 14 speci cally refers to human health: “By 2020, ecosystems that provide essential services, including services related to water, and contribute to health, livelihoods and well-being, are restored and safeguarded, taking into account the needs of women, indigenous and local communities, and the poor and vulnerable.”
The Strategic Plan also includes means of implementation, monitoring, review and evaluation, as well as support mechanisms (strategy for resource mobilization, capacity building, technical and scienti c cooperation).
Connecting Global Priorities: Biodiversity and Human Health 25 • Provide some of the basic tools necessary to Part Two examines how biodiversity is related investigate how biodiversity may influence health to specific thematic areas at the biodiversity– status or health outcomes, for given projects, health nexus, specifically addressing: water policies or plans at varying levels (i.e. from and air quality; agricultural biodiversity and community to the national, regional and global food security; nutrition and health; infectious levels). diseases; microbial communities and NCDs; the contribution of biodiversity to health care and This work is aimed primarily at policy-makers, the impact of pharmaceuticals on biodiversity; practitioners and researchers working in the traditional medicine; physical and mental health fields of biodiversity conservation, public and well-being, and cultural ecosystem services. health, development, agricultural and other relevant sectors. Its findings suggest that greater Finally, Part Three discusses some critical cross- interdisciplinary and cross-sectoral collaboration is cutting themes at the intersection of biodiversity essential for the development of more coordinated and health, including climate change, disaster and coherent policies aimed at addressing the risk reduction, and sustainable consumption and tripartite challenge of biodiversity loss, the production. It also suggests broad strategies and global burden of ill-health and development. approaches to integrate a consideration of the Interdisciplinary scientific investigation and linkages between biodiversity and human health approaches are critical to meeting these challenges. into public policy, and identifies preliminary This volume demonstrates the need to foster tools and research gaps for further exploration. greater synergy across scientific disciplines, social The volume concludes by highlighting how better sciences and humanities, with more coherent consideration of the linkages between biodiversity strategies across all levels of governance. The and human health will contribute to the post-2015 full involvement of all segments of society, Development Agenda. including local communities, will also be needed as we transition toward a new era of sustainable This State of Knowledge Review builds upon and development. extends the health synthesis of the Millennium Ecosystem Assessment (WHO 2005) and other Some of the linked variables at the junction recent studies (Chivian & Bernstein 2008; Sala of biodiversity and human health described et al. 2012). As further discussed in Chapter 2, throughout this volume are schematically the review casts a wide net, considering the direct represented in Figure 1. and indirect linkages between human health and biodiversity (including its components and This volume comprises three main parts. ecosystems).
Part One defines the concepts of biodiversity and Biodiversity plays a critical role in ecosystem health, introduces concepts such as the social functioning and also yields direct and indirect and environmental determinants of health, benefits (or ecosystem services) that support biodiversity and ecosystem services, and provides human and societal needs, including good health, a broad overview of the different ways in which food and nutrition security, energy provision, biodiversity and health are linked. It also considers freshwater and medicines, livelihoods and common drivers of change that impact on both spiritual fulfilment. These, in turn are mediated global public health and biodiversity, and calls for by the social determinants of health (such as age, the use of integrative, interdisciplinary framework gender and access to health care). Multidisciplinary approaches that attempt to unite different fields approaches can help us to better analyse and such as “One Health”, “Ecohealth” and the evaluate the interactions between these different ecosystem approach. variables to better develop more coordinated, coherent and integrated policies.
26 Connecting Global Priorities: Biodiversity and Human Health ǡǤǢǰǭǠɻ Linkages and co-dependencies at the intersection of biodiversity and human health
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Connecting Global Priorities: Biodiversity and Human Health 27 2. Biodiversity and human health linkages: concepts, determinants, drivers
LUIS ASCUI FOR ASIAN DEVELOPMENT BANK / FLICKR of change and approaches to integration
1. BIODIVERSITY, HEALTH AND form the web of life, of which humans are an INTERACTIONS integral part and upon which they depend for their very survival. It is the combination of these life 1.1 What is biodiversity? forms and their interactions with one another, and with the surrounding environment, that makes Biological diversity, most commonly used in its human life on earth possible (CBD 2006). contracted form, biodiversity,¹ is the term used to describe the variety of life on earth, including The Convention on Biological Diversity (CBD) animals, plants and microbial species. It has defines biodiversity as: “the variability among been estimated that there are some 8.7 million living organisms from all sources including, eukaryotic species on earth,² of which some inter alia, terrestrial, marine and other aquatic 25% (2.2. million) are marine, and most of them ecosystems and the ecological complexes of which have yet to be discovered (Mora et al. 2011). they are part; this includes diversity within species, Biodiversity not only refers to the multitude of between species, and of ecosystems”.⁴ Biodiversity species on earth, it also consists of the specific encompasses much more than the variety of life on genetic variations and traits within species (such earth; it also includes biotic community structure, as different crop varieties),³ and the assemblage of the habitats in which communities live, and the these species within ecosystems that characterize variability within and among them. agricultural and other landscapes such as forests, wetlands, grasslands, deserts, lakes and rivers. Thus, biodiversity extends beyond the simple Each ecosystem comprises living beings that measurement of species numbers to include the interact with one another and with the air, complex network of interactions and biological water and soil around them. These multiple structures that sustain ecosystems (McCann interconnections within and between ecosystems 2007; Maclaurin and Sterelny 2008). Although
¹ It has been argued that the rapidly popularized term biodiversity was coined by Walter G. Rozen in 1986 (e.g. Maclaurin and Sterelny 2008; Sarkar and Margules 2002). ² Eukaryotic cell species (including humans) are those that have a nucleus and internal compartments. Conversely, most prokaryotic cell species are made up of a single cell. ³ For example, two species of rice contain over 120 000 genetically different varieties (CBD 2006). ⁴ Convention on Biological Diversity, Article 2.
28 Connecting Global Priorities: Biodiversity and Human Health “species richness” is one of biodiversity’s key services that they provide to public health and to components, the two terms are not synonymous. economic development alike (MA 2005a, b). The widely accepted definition of biodiversity adopted by the CBD is flexible, inclusive, and The findings of the Millennium Ecosystem reflective of the levels and complexities of biotic Assessment and of large-scale national and and abiotic interactions. It recognizes levels of regional assessments have made it clear that it variability within species, between species, and is increasingly important for people in the public within and between ecosystems as integral to the health sector to recognize that human health ecological processes of which they are a part (Mace and well-being are influenced by the health and et al. 2012). It is also understood that variability integrity of local ecosystems, and frequently by manifests itself differently at various temporal and the health of local plant and animal communities. spatial scales (Nelson et al. 2009; Thompson et The interactions between people and biodiversity al. 2009). can determine the baseline health status of a community, providing the basis for good health The scope of the Convention is broader still; and secure livelihoods, or creating the conditions its objectives – “the conservation of biological responsible for morbidity or mortality.⁵ In many diversity, the sustainable use of its components cases, the long-term success and sustainability and the fair and equitable sharing of the of public health interventions is determined by benefits arising out of the utilization of genetic the degree to which ecological factors are taken resources” – indicate an interest in the components into account. In the same way that economic of biodiversity (including individual species) and factors must often be addressed, biodiversity and genetic resources. its importance to the functioning of ecosystems must also be considered. As noted in the earlier 1.2 What is health? definition of biodiversity, this concept must also be explored at multiple geographical and temporal The constitution of the World Health Organization scales for the health sector. Public health policies (WHO) defines health as “a state of complete must also ensure that the relevance of biodiversity physical, mental and social well-being and not is assessed and accounted for within various plans merely the absence of disease or infirmity”. or projects. Similarly, biodiversity conservation Health is a dynamic concept that is influenced by initiatives must also account for how such projects a range of interacting social, biological, physical, may affect public health, whether the resulting economic and environmental factors. As such, impacts are positive or negative. As the global health is one of the most important indicators of community works towards the implementation sustainable development. While social status and of the United Nations Sustainable Development economic security are perhaps most important in Goals, the importance of biodiversity to determining an individual’s capacity to manage her livelihoods, poverty eradication and human well- or his health and to maintain a healthy lifestyle, being is also of paramount importance. the role of environmental and ecosystem change in determining health status are increasingly 1.3 Biodiversity–health interactions recognized within the health, environment and development communities. The 2005 reports Biodiversity and human health are linked in of the Millennium Ecosystem Assessment many ways, and a broad scope is taken in this have helped to increase understanding of the State of Knowledge Review. Further to Mace relationships between the environment and and colleagues (2012), we look at “biodiversity” human well-being. Together, these reports have in a broad sense, including not only species marked a turning point in highlighting the richness and the genetic diversity within importance of ecosystems and the goods and species (“biodiversity, narrow sense”) but also
⁵ Morbidity refers to the incidence of a disease across a population, while mortality refers to the rate of death in a population.
Connecting Global Priorities: Biodiversity and Human Health 29 the components of biodiversity (species and crops and livestock, associated pollinators and genotypes), and habitats and ecosystems. Thus, pest control organisms and in soils – support the distribution and abundance of species, and the agricultural production. Ecosystem services in the extent of natural habitats, are relevant, in addition wider landscape of biodiversity underpin a host to diversity per se. Moreover, we consider not only of ecosystem services, including water provision the direct effects of biodiversity or its components and erosion control. The functioning and integrity on human health, but also the (indirect) effects of the biosphere at a planetary scale (i.e. global that are due to biodiversity’s role in supporting level) is also understood to depend on biodiversity. ecosystem processes and functioning (see section 3). Further, we examine drivers of change that 2. EQUITY AND SOCIAL are common to both biodiversity loss (or change) and health status. Finally, we are also concerned DIMENSIONS OF HEALTH AND with the impacts of the interventions made in the BIODIVERSITY health sector on biodiversity and vice versa. Thus, Human population health is determined, to a large this State of Knowledge Review casts a broader extent, by the social, economic and environmental net than other recent reviews (e.g. Hough 2014). determinants of health (United Nations Task Team on Social Dimensions of Climate Change Like Sandifer et al. (2015), we consider a broad 2011; WHO 2008). The social, economic and range of pathways through which biodiversity may behavioural aspects of the human condition provide health and well-being benefit to people: interact with the environment, including critical psychological (e.g. green spaces and iconic wildlife; elements of biodiversity, biodiversity losses and see Chapter 12), physiological (directly through gains, and ecosystem services. the human microbiome, and indirectly through exercise in green spaces, see Chapters 8 and 12), Biodiversity and its changes (losses and gains) regulation of the transmission and prevalence are, to a great extent, the result of anthropogenic of some infectious diseases (see Chapter 7), influences (Mora and Zapata 2013). The social provision of food and good nutrition (Chapters dimensions of biodiversity are present both in 5 and 6), clean air and water (Chapters 3 and 4), relation to these drivers of change and in relation the provision of traditional and modern medicines to how the impacts of biodiversity change are (Chapters 9 and 11) and the impact of some mediated among groups of differing socioeconomic pharmaceuticals on the environment (Chapter 11). status. Biodiversity loss is impacted by anthropogenic drivers, such as overexploitation of Box 1 and Figure 1 provide a typology of natural resources, human-induced climate change biodiversity–health interactions. and habitat loss. Large-scale social and economic processes and systems affect biodiversity, and the The interactions between biodiversity and social, economic and environmental dimensions of health are manifested at multiple scales from ecological sustainability at risk (UNESCO 2013). individuals, through communities and landscapes to a planetary scale (Figure 1). At the scale of the Environmental determinants of health (such as air individual person, the human microbiota – the quality, food security, water security, freedom from commensal microbial communities present in disease, etc.) are interrelated and adversely affected our gut, in our respiratory, oropharyngeal and by the reduced ability of degraded ecosystems and urogenital tracts and on our skin – contribute to biota to adapt to the impacts of climate change, air our nutrition, help regulate our immune system, pollution, natural disasters or water scarcity. Many and prevent infection. Interactions among family of the dynamics between biodiversity and human members and the wider environment may be health are in the area of infectious, vector-borne important in the maintenance and turnover of diseases. In some cases, biodiversity loss (such as this diversity. At the community level (such as that associated with deforestation) may enhance farms), many aspects of biodiversity – among the risk of some diseases such as malaria (Chaves
30 Connecting Global Priorities: Biodiversity and Human Health Box 1. A typology of biodiversity–health interactions
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$ƩUVWW\SHRILQWHUDFWLRQLVZKHUHELRGLYHUVLW\JLYHVULVHWRKHDOWKEHQHƩWV %LRGLYHUVLW\Î Health). For example, di erent species (as well as crop varieties and livestock breeds) provide nutrients and medicines. Biodiversity also underpins ecosystem functioning, which provides services such as water and air puri cation, pest and disease control, and pollination. Biodiversity can also be a source of pathogens and thus have negative impacts on health. Changes in biodiversity would lead to changes in the health bene ts. Drivers of such changes extend the causal change upstream (Driver of change Î loss of biodiversity Î reduction in health bene ts).
$VHFRQGW\SHRILQWHUDFWLRQDULVHVIURPGULYHUVRIFKDQJHWKDWDƨHFWERWKELRGLYHUVLW\DQGKHDOWKLQ parallel. (Driver of change Î impacts on health and on biodiversity). For example, air and water pollution can lead to biodiversity loss and have direct impacts on health. Deforestation (or other land-use change or ecosystem disturbance) can lead to loss of species and habitats, and also increased disease risk for humans. Conversely, moderated meat consumption can reduce the pressures on biodiversity (less land-use change; lower greenhouse gas emissions) and also have health bene ts for individuals. In addition to the parallel e ects of the driver on biodiversity and health, there may be additional impacts of the change in biodiversity on health. For example, water pollution, in addition to harming health though loss of drinking water uality, could lead to collapse of a uatic ecosystems through eutrophication leading to sh mortality and conse uent negative e ects on nutrition.
(3) A third type of interaction arises from the impacts of health sector interventions on biodiversity (Health intervention Î biodiversity) and of biodiversity-related interventions on health (Biodiversity intervention Î health). For example, use of pharmaceuticals may lead to the release of active ingredients in the environment and damage species and ecosystems. Again, these may have negative knock-on e ects on human health. On the other hand, protected areas or hunting bans could deny access of local communities to bushmeat and other wild foods, with negative nutritional impacts. Positive interactions of this type are also possible. For example, establishment of protected areas may protect water supplies, with positive health bene ts.
Connecting Global Priorities: Biodiversity and Human Health 31 et al. 2011; Hahn et al. 2014; Laporta et al. 2013), in isolation or through an interaction with other while in others, biodiversity gains (such as that determinants) or indirectly (e.g. access to healthy associated with reforestation) may also sometimes food). increase the risk for other diseases (Levy 2013; Ostfeld and Keesing 2000). Detrimental changes to biodiversity and the resulting risks and burden of human health In addition to environmental determinants, problems are inequitably distributed in specific social and economic determinants also influence social–ecological settings. Populations exposed the dynamics between biodiversity changes and to the greenest environments have been found human health. The inequities of how society to also have the lowest levels of health inequality is organized mean that the freedom to lead related to income deprivation, suggesting that a flourishing life and to enjoy good health is healthy physical environments can be important unequally distributed between and within for reducing socioeconomic health inequalities societies. This inequity is seen in the conditions (Mitchell and Popham 2008). Equity issues are of early childhood and schooling, the nature of not only important in relation to different groups employment and working conditions, the physical within a country, but also in relation to different form of the built environment, and the quality of vulnerabilities among countries. Developing the natural environment in which people reside. countries are more reliant on biodiversity and Depending on the nature of these environments, ecosystem services than developed ones, and their different groups will have different experiences health systems are usually less prepared to protect of material conditions, psychosocial support and the health of their populations, which leads to behavioural options, which make them more or greater negative health impacts of biodiversity less vulnerable to poor health. Social stratification change. Between countries, biodiversity loss is likewise determines differential access to and related to income inequality (Mikkelson et al. utilization of health care, with consequences for 2007). For example, over 1 billion people, mainly the inequitable promotion of health and well- in developing countries, rely on fisheries as their being, disease prevention, and recovery from primary source of animal protein (Gutiérrez et al. illness and survival. This unequal distribution 2011). of health-damaging experiences is not in any sense a “natural” phenomenon but is the result Different gender roles in relation to biodiversity of a toxic combination of poor social policies and management, conservation and use can also programmes, unfair economic arrangements have an impact on human health, and more and power relationships. (Commission on Social attention needs to be paid to these gender Determinants of Health 2008). dimensions (WHO 2011, 2008). Access to, use and management of biodiversity have different Population groups more reliant on biodiversity health impacts on women and men and boys and ecosystem services, especially on provisioning and girls, determined by gender norms, roles and services such as timber, water and food, are usually relations (Gutierrez-Montes et al. 2012). Social more vulnerable to biodiversity loss and those norms and values determine different gender less covered by social protection mechanisms roles and relations, which in turn, are translated (e.g. health insurance). Vulnerable groups include into different responsibilities, obligations, benefits indigenous populations, specific groups dependent and rights in relation to biodiversity (Manfre and on biodiversity and ecosystem services and, Ruben 2012). In addition to the lack of political for example, subsistence farmers. Detrimental will, and frequently weak institutional capacity changes to biodiversity and the resulting risks and and legal frameworks that fail to assess and burden of human health problems are inequitably address different gender roles, there is a lack of distributed in specific social–ecological settings. sex-disaggregated data on biodiversity access, These inequalities affect both individual and use and control, which makes it very difficult to community health either directly (whether it be conduct a gender analysis and therefore design
32 Connecting Global Priorities: Biodiversity and Human Health adequate responses targeting specifically those Relevant tools that could be used to understand most vulnerable population groups (Castaneda et the equity and social dimensions of health and al. 2012). biodiversity for any relevant policy or programme include social impact assessments, health impact However, it is widely accepted that many of assessments and strategic impact assessments. the adverse impacts of biodiversity loss are Whatever tool is used, it is key to ensure that all impacting already vulnerable groups of people, health, environmental, and social considerations specifically populations who are dependent and impacts are integrated within the assessment. on biodiversity and ecosystem services (forest As discussed in section 5 of this chapter and dwellers, indigenous populations, women and Part III of this volume, solutions to biodiversity girls, etc.). Biodiversity losses in specific social– and health challenges also necessitate the ecological settings and the resulting health effects sustained engagement of multiple stakeholders, on marginalized populations are often triggered both in governments, civil society, and in by large-scale processes beyond the control nongovernmental and international organizations. of the populations at risk. Climate change or The social sciences are, therefore, important large-scale mining or logging projects may have contributors to research and policy-making in negative impacts on biodiversity, and increase biodiversity and health (UNESCO 2013), and to social and economic inequalities. For example, the large-scale social and behavioural changes it is estimated that 1 billion people only produce required to achieve the objectives of sustainable 3% of global greenhouse gas emissions. A social development. justice perspective is, therefore, needed to address the various equity dimensions in the biodiversity and health dynamic (Walter 2003). 3. BIODIVERSITY, ECOSYSTEM FUNCTIONS AND SERVICES The social sciences are important contributors Scientific knowledge of the impacts of to research and policy-making in biodiversity biodiversity loss on ecosystem functioning has and health. In addition to gender analysis, a increased considerably in the past two decades multifaceted approach is needed to effectively (Balvanera et al. 2014; Cardinale et al. 2012; tackle the equity and social dimensions of health Reis et. al. 2012; Naeem and Wright 2003; and biodiversity. Social research illuminates Loreau et al. 2001; Tilman et al. 1997), as well as social vulnerabilities, and has the potential to corresponding knowledge of its implications for engage and mobilize people most affected by public health (Myers et al. 2013). In this section, biodiversity loss, e.g. indigenous populations. we summarize key elements of the relationship The social sciences also play an important role in between biodiversity, ecosystems and ecosystem determining policy options for health, biodiversity functioning, its connection to ecosystem services, and ecosystem management (Artner and Siebert and the components that influence the quantity, 2006; Duraiappah and Rogers 2011; Gilbert et al. quality and reliability of ecosystem services, and 2006). Inter-, multi- and transdisciplinary research that contribute to ecosystem resilience. can provide valuable insights into the drivers of disease emergence and spread, contribute There is strong evidence of the relationship to identifying previous patterns of disease risk, between biodiversity and ecosystem functioning and help to predict future risks through the and, in some cases, we can directly link this to the lens of social–ecological systems (Folke 2006; ecosystem services necessary to sustain human Gilbert et al. 2006; UNESCO 2013). For example, health (Loreau et al. 2001; Balvanera et al. 2006; interdisciplinary work on the social determinants Cardinale et al. 2012; Balvanera et al. 2014). In of health can also provide valuable insights into other cases, we do not yet have complete evidence the drivers of disease emergence and spread, of this relationship (Schwartz et al. 2000; Cardinale contribute to identifying previous patterns of et al. 2012). While there is broad consensus within disease risk and help to predict future risks. the scientific community on several aspects of
Connecting Global Priorities: Biodiversity and Human Health 33 the relationship between biodiversity, ecosystem The specific components of biodiversity (e.g. functioning and the consequences of its loss on genes, species) and attributes (e.g. variability, the ability of ecosystems to provide services, composition) that underpin the ecosystem the full range of impacts of biodiversity loss on services that, in turn, support human health ecosystem functioning is not fully understood and well-being may differ among the services or (Reiss et al. 2009; Hooper et al. 2005). goods in question, and on the processes upon which they rely. The diverse functional traits of 3.1 Biodiversity, ecosystem processes species within a community can also influence and properties ecosystem properties, and their examination can contribute to understanding variations Ecosystems comprise physical and chemical in ecosystem functions (Hooper et al. 2005; biotic (e.g. plants, animals, humans) and abiotic Tilman et al. 1997; Haines-Young and Potschin (e.g. light, oxygen, temperature, soil texture and 2010; Naeem and Wright 2003) and resilience chemistry, nutrients) interactions (Currie 2011). (Mori et al. 2013; Elmqvist 2003). In this sense, Ecosystem processes include decomposition, species’ functional characteristics can be critical nutrient cycling (e.g. water, nitrogen, carbon to ecosystem services; their loss can result in and phosphorus cycling), production (of plant permanent changes. matter), as well as energy and nutrient fluxes. A healthy ecosystem – one that performs its Twenty years of work on the relationship between various functions well and where equilibrium is biodiversity and ecosystem functioning has maintained – is dependent upon biodiversity. generated a number of controversies and spurred This is often referred to as ecosystem integrity, efforts to develop scientific consensus. Cardinale ecosystem stability or ecosystem health. et al. (2012) conclude that diverse communities tend to be more productive both because they Fluxes of energy, biogeochemical cycles such as contain key species that have a large influence on nutrient cycling and oxygen production, and productivity, and because differences in functional community dynamics such as predator–prey traits among organisms increase the total capture interactions are regulated by the earth’s biota. The of resources (light, water). Thus, biodiversity attributes (including composition and abundance) loss reduces the efficiency by which ecological and interactions of biotic and abiotic components communities capture biologically essential determine ecosystem processes and their properties, resources, produce biomass, and decompose and they influence changes in each of the latter and recycle biologically essential nutrients. They over space and time (Reiss et al. 2009). The report that the impact of biodiversity on any single provision of essential goods and services, including ecosystem process is non-linear and saturating, those essential to sustaining human life, is reliant such that change accelerates as biodiversity loss on the properties, processes and maintenance of increases. They also point to mounting evidence ecosystems (Naeem and Wright 2003; Balvanera that biodiversity increases the stability of et al. 2006; Reiss et al. 2009, 2010). The quality, ecosystem functions through time. quantity and security of the essential services that we derive from ecosystems are determined 3.2 Ecosystem services by several dynamic and interlinked factors, including different components of biodiversity, Human health ultimately depends upon ecosystem underlying physical and biological processes (each products and services (e.g. availability of fresh with their own characteristics and thresholds), and water, food and fuel sources), which are required complex responses to environmental stressors for good health and productive livelihoods. such as pollution and climate change (Mace 2012; Many ecosystems, such as marine areas, forests, Balvanera et al. 2006). grasslands and wetlands, contribute to regulation of the world’s climate, and can also influence local microclimates. People depend directly on
34 Connecting Global Priorities: Biodiversity and Human Health ASIAN DEVELOPMENT BANK / FLICKR ecosystems in their daily lives, including for the in ecosystem services affect livelihoods, income, production of food, medicines, timber, fuel and local migration and, on occasion, may even cause fibre, but also in ways that are not always apparent political conflict. or appreciated. Our natural capital is not only the source of our food, but also provides less tangible The first comprehensive scientific appraisal of the benefits, such as spiritual enrichment, and areas condition and trends of ecosystem services for for recreation and leisure. Ecosystems also play health and well-being, the Millennium Ecosystem important roles in the water cycle, regulating Assessments,⁶ adopted four major categories of the flow of water through the landscape, and ecosystem services: provisioning services such the amount of sediments and contaminants as water, food and timber; regulating services that affect important water resources. These such as pest control, climate regulation and and other important benefits, called “ecosystem regulation of water quality; cultural services goods and services”, are essential to our society, including recreational and spiritual benefits; and our economic development, and our health and supporting services such as photosynthesis, soil well-being. Biodiversity loss can have direct, and formation and nutrient cycling. Each category is sometimes significant, human health impacts, vital for human and community health, as well particularly if ecosystem services are no longer as ecosystem resilience. The study concluded that adequate to meet social needs. Indirectly, changes ecosystems processes have changed more rapidly
⁶ While the Millennium Assessment has been instrumental in evaluating the conditions and trends of ecosystems for health, the notion of ecosystem services can be traced as far back as the 1970s (Haines-Young and Potschin 2010). The impetus for placing human needs at the centre of biodiversity management is also covered by the 12 principles of the ecosystem approach adopted by the Convention on Biological Diversity (COP 5 decision the V/6).
Connecting Global Priorities: Biodiversity and Human Health 35 since the mid-twentieth century than at any other be transformed if a change in ecosystem structure time in recorded human history. Among the 24 crosses a given threshold. Structural changes categories of ecosystem services assessed, 15 of may be manifested as a result of the removal them were in a state of decline, the majority of of key predators or other species from the food them regulating and supporting services (MA web (Thomson et al. 2012), the simplification of 2005). Declining services include pollination, vegetation or soil structure, increased or decreased the ability of agricultural systems to provide pest aridity, species loss and many other factors. control, the provision of freshwater, marine fishery Biodiversity loss is continuing, and in many cases production, and the capacity of the atmosphere increasing (Butchart et al. 2010; Tittensor et al. to cleanse itself of pollutants. Most ecosystem 2014). Biodiversity loss has been identified as one services that were found to be increasing were of the most critical drivers of ecosystem change provisioning services, including crops, livestock (Hooper et al. 2012). Changes in the diversity of and aquaculture. Consumption was also increasing species that alter ecosystem function may directly of all services across all four categories. These reduce access to ecosystem services such as food, increases have helped to generate and sustain water and fuel, and also alter the abundance of the increases in human health and well-being species that control critical ecosystem processes seen over the same period. However, the decline essential to the provision of those services (Chapin of many other ecosystem services – mostly the et al. 2000). regulating and supporting services – threatens to undermine this progress, presenting threats Ecosystem regime shifts, including “tipping to human health and well-being (Chivian and points”, have been widely described and Bernstein 2008; Haines-Young and Potschin 2010; characterized at local levels (for example, McMichael and Beaglehole 2000), several of which eutrophication of freshwater or coastal areas are described throughout this technical volume. due to excess nutrients; collapse of fisheries due to overfishing; shifts of coral reefs to algae- In general, aggregate terms, socioeconomic dominated systems; see Sheffer 2009; CBD 2010). progress has benefited human health and well- There is growing concern that regime shifts being, but at a cost to the underlying natural could occur at very large spatial scales over the resource base. Raudsepp-Hearne et al. (2010) next several decades, as human–environment examined several hypotheses to explain this systems exceed limits because of powerful and apparent paradox and call for efforts to expand widespread driving forces that often act in our understanding of the complex cross-scale combination: climate change, overexploitation of interactions between ecosystem services, human natural resources, pollution, habitat destruction, activities and human well-being. and the introduction of invasive species (Leadley et al. 2014; Barnosky et al. 2012; Hughes et al. 3.3 Biodiversity loss, biosphere 2013). Cardinale et al. (2012) suggest that the integrity and tipping points impacts of biodiversity loss on ecological processes might be sufficiently large to rival the impacts of Ecosystem management strategies aimed at climate change and many other global drivers of maximizing conservation and public health environmental change. co-benefits must consider that systems have emergent properties that are not possessed by Leadley et al. describe scenarios for regional-scale their individual components: they are more shifts that would have large-scale and profound than the sum of their parts. One example is the implications for human well-being (Leadley resilience of ecosystems to absorb shock in the et al. 2014). The unprecedented pressures of face of disturbance (such as pests and disease, human activity on biodiversity and on the climate change, invasive species, or the harvesting earth’s ecosystems may also lead to potentially of crops, animals or timber) and return to their irreversible consequences at a planetary scale, original structure and functioning. Ecosystems can and this prospect has led to the identification of
36 Connecting Global Priorities: Biodiversity and Human Health processes and associated thresholds, and to the productive capacity, and concomitant pressures development of various approaches⁷ to define on the earth’s biological resources may undermine preconditions for human development on a the ability of ecosystems to provide life-sustaining planetary scale (Rockström et al. 2009; Barnosky services (CBD 2010; McMichael and Beaglehole et al. 2012, Steffen et al. 2015; see also Mace et 2000). al. 2014). Global efforts to pursue sustainable development will continue to be compromised if Social change and development biases (such these critical pressures are not countered in a more as urbanization, poverty and inequity) further rigorous, systematic and integrated fashion. influence the drivers of biodiversity loss and ill- health. Macroeconomic policies and structures, and public policies that provide perverse 4. DRIVERS OF CHANGE incentives or fail to incorporate the value of In recent decades, the impact of human activity on biodiversity frequently compound the dual the natural environment and its ecosystems has threat to biodiversity and public health. Both been so profound that it has given rise to the term the impacts of biodiversity loss and ill-health anthropocene, popularized by Nobel prize-winning are likely to be most pronounced among the chemist Paul Crutzen, delimiting a shift into a new world’s poorest, most vulnerable populations,⁸ geological epoch, in which human activity has which are often those most immediately reliant become the dominant force for environmental on natural resources for food, shelter, medicines, change (Crutzen 2002). Anthropogenic pressures, spiritual and cultural fulfilment, and livelihoods demographic change, and resulting changes in (MA 2005). As indicated above, these vulnerable production and consumption patterns are also groups are also generally those least able to access among the factors that contribute to biodiversity substitutes when ecosystem services are degraded. loss, ill-health and disease emergence. These In addition to the immediate usefulness of natural pressures have shown a “great acceleration”, resources, the intrinsic value of nature to so many, especially in the past 50 years (Steffen et al. its cultural and spiritual contributions, and the 2015b). While some human-induced changes right of future generations to inherit a planet have garnered public health benefits, such as the thriving with life also should not be overlooked. provision of energy and increased food supply, in many other cases they have been detrimental to The drivers (causes) of ill-health and human, the environment, ecosystems and corresponding animal and plant disease often overlap with the services, as well as human health (Myers et al. drivers of biodiversity loss. Some of the principal 2013; Cardinale et al. 2012; Balmford and Bond common drivers, identified in the third edition 2005; McMichael and Beaglehole 2000). In many of Global Biodiversity Outlook (GBO 3) and cases, the ecological implications are immense and reiterated in its fourth edition, include: habitat the need to address them pressing if our planet change, overexploitation and destructive harvest, is to provide clean water, food, energy, timber, pollution, invasive alien species and climate medicines, shelter and other benefits to an ever- change (CBD 2010, 2014), all of which may be increasing population. The rise in demographic exacerbated by environmental changes. pressures and consumption levels will translate into unprecedented demands on the planet’s
⁷ Rockström and colleagues (2009), updated by Steffen et al. (2015), describe nine “planetary boundaries” that have been identified: including biosphere integrity (terrestrial and marine); climate change; interference with the nitrogen and phosphorus cycles; stratospheric ozone depletion; ocean acidification; global freshwater use; changes in land use; chemical pollution; and atmospheric aerosol loading. The metrics used to define the biodiversity/biosphere integrity planetary boundaries has been challenged, including biodiversity loss, for its measurement of biodiversity as “global species extinction rate” and “the abundance, diversity, distribution, functional composition and interactions of species in ecosystems” were not considered in its 2009 (Mace et al. 2014: 296). ⁸ For example, Butchart et al. (2010) indicate that more than 100 million of the world’s poor people, especially reliant on biodiversity and the services it provides, live in remote areas within threatened ecoregions.
Connecting Global Priorities: Biodiversity and Human Health 37 ASIAN DEVELOPMENT BANK / FLICKR
As the majority of human infectious agents much more systematic assessment as well as more have originated in animals (known as “zoonotic structured, coherent, and cross-cutting policies diseases”), including the infection leading to and strategies. These critical linkages should HIV/AIDS (from chimpanzees hunted for human be translated into concrete policy targets as we consumption), animal and environmental links embark on a new series of global commitments to human infectious diseases are highly relevant on sustainable development as the MDGs reach (Taylor et al. 2001). While the ties between their term in 2015. infectious diseases and biodiversity are perhaps the most frequently cited, biodiversity loss also 4.1 Habitat change has significant and myriad implications for noncommunicable diseases (NCDs) and the Land-use change (e.g. full or partial clearing socioeconomic determinants of health. Examples for agricultural production or natural resource of these are highlighted for each of the major extraction, such as for as timber, mining and oil) is drivers of biodiversity loss identified above. the leading driver of biodiversity loss in terrestrial ecosystems. Alteration of native habitats may also The pressing need to jointly address both social reduce resilience; for example, deforested areas and environmental determinants of health may experience soil erosion, increasing ecological (Bircher and Kuruvilla 2014) has been widely risks of extreme weather events such as sudden acknowledged through various multilateral flooding, and limited food production potential agreements. However, the role of biodiversity as a from reduced soil enrichment. Furthermore, mediating influence on human health (through the habitat changes such as deforestation directly loss of ecosystem services, which are themselves alter the capacity of carbon sinks and thus further mediated by ecological processes), while gaining increase the risks of climate change. more widespread attention since Rio, merits
38 Connecting Global Priorities: Biodiversity and Human Health Land-use change is also the leading driver of risks. Intensification of harvest and exploitative disease emergence in humans from wildlife practices, such as the mixing of wildlife and (Jones et al. 2008). Changes to habitats, including domestic species in markets, as well as the mixing through altered species composition (influenced and spread of their pathogens, can create global by conditions that may more favourably support epidemics, as seen with the 2003 outbreak of carriers of disease, as seen with malaria- severe acute respiratory syndrome (SARS). harbouring vectors in cleared areas of the Amazon) and/or abundance in an ecosystem (and thus 4.3 Pollution potential pathogen dispersion and prevalence), and the establishment of new opportunities for Environmental pollution poses direct threats to disease transmission in a given habitat, have both biodiversity and human health in many ways. major implications for health. Human-mediated Pollutant exposure risk is potentially increased changes to landscapes are accompanied by human for top-of-the-chain consumers such as humans encroachment into formerly pristine habitats, and marine mammals through bioaccumulation often also accompanied by the introduction of along the food chain, as seen with mercury. Air domestic animal species, enabling new types pollution exposure presents risks of respiratory of interactions among species and thus novel diseases. Other so-called “lifestyle diseases” (such pathogen transmission opportunities. as obesity and diabetes) may be influenced by access to physical fitness, which may be limited by outdoor and indoor air pollution levels. 4.2 Overexploitation and destructive Chemicals, such as pharmaceuticals or plastics harvest containing endocrine-disrupting substances, may Overexploitation of biodiversity and destructive be dispersed on entering water sources and other harvesting practices reduce the abundance of the environmental settings, posing acute, chronic or populations of species concerned, and in some recurring exposures in humans and animals. Wide- cases, can threaten the survival of the species itself. scale application of antimicrobials for human and Demand for wild-sourced food is increasing in animal medicine and food production, much of some areas. The wildlife trade, for purposes such as which is excreted into the environment, is resulting supplying the pet trade, medicinal use, horticulture in rapid changes to microbial composition, as and luxury goods, is increasing globally, well as driving development of antimicrobial- exacerbating pressures on wild populations. resistant infections. Contaminated water may Practices for harvest, including unregulated enable persistence of human infectious agents administration of chemicals for the capture of and their diseases, such as cholera-causing Vibrio animals (e.g. the release of cyanide or trawling and parasitic worm-transmitted schistosomiasis. practices for fishing) may also have impacts on non-target species, and/or unsustainable harvests 4.4 Invasive alien species may alter ecological dynamics, such as diminished potential for seed dispersion and implications Invasive alien species (IAS) pose direct threats to for food chains (affecting also the humans who native and/or endemic species. The introduction of depend on them). As native biodiversity declines, IAS may result in invasive species out-competing local protein sources from subsistence hunting or important food and traditional medicine sources for gathering may be diminished, causing inadequate human populations, as well as causing fundamental nutrition if alternatives are unavailable or lack impacts on ecosystems that may influence health necessary nutrients. Additionally, bushmeat processes. Examples of this include impaired water hunting and consumption, sometimes in areas quality from the introduction of zebra mussel in that have not been previously targeted for food the United Kingdom and North America, altered sourcing (for example, in newly established soil quality through the spread of weeds, and the mining camps in formerly pristine habitat) may reduced species decomposition facilitated by feral pose direct novel infectious disease transmission pigs grazing on native plants as well as agricultural
Connecting Global Priorities: Biodiversity and Human Health 39 land. In addition to these detrimental impacts, IAS (recent immigrants) might not have immunity to pose risks of disease introduction and spread for zoonotic diseases endemic to the area, making native wildlife, agricultural species and humans. them particularly susceptible to infection. Women As global trade and travel continues to increase, so who are required to butcher harvested wildlife, or do the health risks; changing climactic conditions men who hunt the game, may be particularly at may also enable establishment of IAS where risk. Moreover, those sectors of society that lack climate would have previously limited survival, adequate income to purchase market alternatives demonstrated with alarming clarity in the case may be more likely to access forest resources of the pine mountain beetle invasion in western (including wildlife) for food and trade. Thus, Canada. there are likely socioeconomic and gender-specific relationships to these types of disease risks and 4.5 Climate change exposures (WHO 2008). Disease may also worsen the economic status of a population; vector-borne The direct and indirect impacts of climate change and parasitic diseases, the burden of which is also pose risks for biodiversity and health; driven by ecological conditions, have been shown for example, shifts in species ranges may also to worsen the poverty cycle (Bonds et al. 2012). facilitate changes in pathogen distribution and/ or survival, as projected for Nipah virus (Daszak 4.7 Urbanization as a challenge and et al. 2013). Climate change also contributes to ocean acidification, coral bleaching and diseases an opportunity to manage ecosystem in marine life, as reef-building coral species are services threatened with extinction. These in turn have Urbanization, the demographic transition from significant implications for the large biological rural to urban, is associated with shifts from an communities that coral reefs support and that agriculture-based economy to mass industry, sustain human health (Campbell et al. 2009). More technology and service.⁹ With the majority of the extreme weather patterns and rising sea levels world’s population now living in urban areas and (e.g. drought, flooding, early frost) may also be this proportion expected to increase, it is expected detrimental to food and water security, especially that urban health should become a major focus for populations dependent on subsistence farming at the intersection of global public health and and natural water sources. Human populations conservation policy.¹⁰ Urbanization is also closely may also suffer acute health impacts from extreme linked with the social determinants of health, weather (e.g. heat or cold exposure injuries). including development, poverty and well-being.
4.6 Demographic factors, including While urbanization is often associated with migration increasing prosperity and good health, urban populations also demonstrate some of the world’s In addition to the direct drivers of biodiversity most prominent health disparities, in both low- loss, large-scale societal and demographic and high-income countries. Rapid migration from changes, or intensified reliance on ecosystems rural areas as well as natural population growth are for subsistence or livelihoods, often linked to putting further pressure on limited resources in biodiversity changes, may also impact vulnerability cities, and in particular, in low-income countries.¹¹ to disease. For example, new human inhabitants
⁹ For the first time in history, the majority of the world’s population lives in cities, and this proportion continues to grow. One hundred years ago, 20% of the people lived in urban areas. By 2010, this proportion increased to more than half. By 2030, it is expected that the number of people in urban areas will increase to 60%, and in 2050, to 70%. For example, see World Health Organization Global Health Observatory (GHO) data: urban population growth. (www.who.int/gho/urban_ health/situation_trends/urban_population_growth_text/en/, accessed 30 May 2015). ¹⁰ To exemplify this trend and consequent shifts in health, WHO has been coordinating initiatives such as the “World Health Day” and “Urban Health”. ¹¹ World Health Organization. Urban health. (http://www.who.int/topics/urban_health/en/, accessed 30 May 2015).
40 Connecting Global Priorities: Biodiversity and Human Health Much of the natural and migration growth in and health in research and policy, the adoption urban populations is among the poor. More than of multidisciplinary approaches that incorporate 1 billion people – one third of urban dwellers – live contributions from both the social and natural in slum areas, which are often overcrowded and sciences is needed. The EcoHealth, One Health are affected by life-threatening conditions (UNDP and “one medicine” approaches are part of a family 2005). In low-income countries, disparities will of approaches that aim to bridge human health continue to rise as the combination of migration, and the health of other species or ecosystems natural growth and scarcity of resources makes it (whether defined as disease outcomes, and/or the more difficult to provide the services needed by functioning of an ecosystem/provisioning of its city dwellers (UN-Habitat 2013).¹² Poorly planned services) to address complex challenges faced by or unplanned urbanization patterns also have the global health and environmental communities. negative consequences for the health and safety of In this volume, they are referred to as “One Health people, including decreased physical activity and approaches”. unhealthy diets, which lead to increased risks for NCDs such as heart disease, cancer, diabetes and They are also closely related to the ecosystem chronic lung disease (WHO 2010). approach adopted under the CBD.¹⁴ While evolving from different sectors (the one medicine Urbanization also creates new challenges for approach from veterinary and human medicine, biodiversity conservation; the development of with a focus on comparative medicine and links cities is one of the most important drivers of between livelihoods, nutrition and health; the land-use change.¹³ Moreover, it was estimated Ecosystem and EcoHealth approach from the that up to 88% of protected areas likely to be ecology and biodiversity communities, focusing affected by new urban growth are in countries on ecosystem, societal and health links; and the of low-to-moderate income (McDonald et al. One Health approach primarily from conservation 2008). While cities typically develop in proximity medicine, with a focus on public and animal to the most biologically diverse areas (Seto et al. health, development and sustainability) (Zinsstag 2011), relatively little attention has been paid et al. 2011), at their core they share the common to how cities can be more biodiverse or to the goal of a more comprehensive understanding of importance of maintaining biodiverse ecosystems the ecosystem-based dynamics of health (e.g. for human health (Andersson et al. 2014). Several socioecological systems) than can be yielded health benefits can potentially be derived from through a single-species perspective alone. integrating biodiversity into urban planning Given the integral links between biodiversity schemes, and broader conservation and public and human health, these approaches consider health policies. the connections between humans, animals and the environment, and can thus promote a more 5. INTEGRATING BIODIVERSITY complete understanding of mutual dependencies, risks and solutions. These perspectives allow us to AND HUMAN HEALTH: move beyond single-silo viewpoints (e.g. human APPROACHES AND FRAMEWORKS or veterinary medicine exclusively) to a broader In large part, the biodiversity and health and more upstream consideration of the drivers, sectors have worked separately to achieve their detection, control and prevention of disease. respective goals. To better integrate biodiversity
¹² World Health Organization. WHO Global Health Observatory (GHO) data: urban population growth. (www.who.int/gho/ urban_health/situation_trends/urban_population_growth_text/en/, accessed 30 May 2015). ¹³ For each new resident, rich countries add an average of 355 square meters of built-up area, middle-income countries 125 square meters, and low-income countries 85 square meters (McDonald et al. 2008). ¹⁴ https://www.cbd.int/ecosystem/
Connecting Global Priorities: Biodiversity and Human Health 41 The value of One Health approaches is increasingly move from our currently reactive public health being appreciated for infectious disease prevention measures to more preventive actions; similarly, and control, seeing application for zoonotic this may benefit biodiversity and maintenance diseases such as avian influenza and rabies (Gibbs of ecosystem services through consideration et al. 2014), and based on the overlapping drivers of another potential aspect of impacts to an of disease emergence and spread and biodiversity ecosystem. loss, as well as domestic animal–wildlife and human transmission cycles (GBO3; Jones et al. Involvement of the social sciences, including 2008). In addition, One Health and Ecosystem disciplines such as economics and anthropology, approaches have wider potential applications and can help to further address socioecological benefits, including the following: challenges, incorporating the social as well as environmental determinants of health. Synergies 1) to help inform our understanding of the across these and other sectors may lead to cost– health services provided by biodiversity, as well effective and more upstream disease prevention as how anthropogenic changes to an ecosystem or and management strategies, as well as have biodiversity may impact disease risks. Ecosystems implications for biodiversity. In addition to may provide health-benefiting functions, such as interdisciplinary and cross-sectoral collaboration, toxin remediation by filtration mechanisms in addressing the common challenges faced by the wetlands (Blumenfeld et al. 2009). These functions global health and biodiversity conservation and their underlying mechanisms may be missed communities also necessitates the engagement when focusing on a single species; of many stakeholders, including governments, civil society, nongovernmental and international 2) to provide important knowledge for organizations, as well as indigenous peoples conservation and agricultural efforts, given and local communities. Through integrated the impacts of disease on agricultural and wild approaches such as the One Health approach, species. Several disease risks for human and researchers, practitioners, policy-makers and domestic animals also pose risks for biodiversity; other stakeholders are better able to unravel the for example, while primarily maintained by intricate web of challenges that they jointly face, domestic dogs, wildlife represents the majority and generate new insights and knowledge to find of species susceptible to rabies, with some wild common solutions or, when these are not possible, canid populations suffering severe declines from carefully assess and manage trade-offs (Romanelli the disease (Machalaba and Karesh 2012); et al. 2014a,b).
3) for assessment of environmental health Recently, the Intergovernmental science-policy exposures and outcomes; in addition to being Platform for Biodiversity and Ecosystem Services possible links in the food chain, wildlife may serve has developed a conceptual framework linking as sentinels for ecosystem changes and potential biodiversity, ecosystem services and human well- human risks, as seen with Ebola (Karesh and Cook being (Díaz et al. 2015 a,b). The framework draws 2005) as well as toxin exposures (Buttke 2011). upon the Millennium Assessment framework, but As shown in Figure 1, this may lead to earlier goes further in highlighting the role of institutions, detection and possible prevention and mitigation and in explicitly embracing different disciplines opportunities (Karesh et al. 2012). and knowledge systems (including indigenous and local knowledge) in the co-construction of Implementation of a One Health approach brings assessments of the state of the world’s biodiversity multiple sectors together to view our shared health and the benefits it provides to humans. across an ecosystem or specific disease challenge. Employing multispecies disease surveillance or risk analysis, with data sharing across human, agriculture and environment experts, can help
42 Connecting Global Priorities: Biodiversity and Human Health 6. CONCLUSION: A THEMATIC ecosystem processes and services, and the APPROACH TO COMMON ultimate impacts on human health, which are not easily reduced to simple causal chains. LINKAGES These links are frequently non-linear¹⁵ (Kremen There is a pressing need to better understand 2005), difficult to predict, and are sometimes the relationship between biodiversity and irreversible as biotic–abiotic interactions largely public health, and this volume seeks to make a occur at the level of ecological processes rather contribution to this imperative. We already know than in the delivery of the services themselves¹⁶ that biodiversity and corresponding ecosystem (Carpenter et al. 2009; Mace 2012). The difficulties services, and public health intersect on numerous inherent in determining these causal links in no fronts and these linkages are further explored in way diminishes the importance of seeking to each of the thematic sections that follow. identify them.
This demands an understanding of biodiversity’s Understanding the links between the weakening fundamental contribution to essential life- of ecosystem services and human health is supporting services, such as air and water quality essential to shaping robust policies, expanding and food provision. It also requires mapping the our scientific understanding of the health needs role of biodiversity in human health on many of human communities, and to meeting new and other fronts, including nutritional composition; existing challenges to public health in the face of micro- and macronutrient availability and NCDs; global environmental change (McMichael and its applicability in traditional medicine and Beaglehole 2000). biomedical research that relies on plants, animals and microbes to understand human physiology; Although the links between biodiversity and and its relationship with processes affecting human health are fundamental, they are often infectious disease reservoirs. We also need to diffused in space and time, and there are a number further explore the role of microbial diversity in of actors that moderate the critical underlying our internal biomes in human health and disease; relationships. To date, work at the biodiversity– the threats of IAS to ecosystems and human health nexus has been insufficient, which may at health; the positive feedback loops associated least in part be explained by these diffuse links. with climate change; and many other associations. While One Health and similar approaches have Our current state of knowledge of these and other begun to garner greater international acceptance, themes is explored in greater detail in each of the primary focus of interventions in the public the thematic sections included in Part II of this health sector continue to tend toward curative technical volume. interventions rather than preventive (upstream) interventions, which also consider the social and While there has been considerable scientific environmental determinants of health. A powerful progress in understanding these linkages, much argument can be made for the critical need to more interdisciplinary and cross-sectoral work is incorporate these dimensions to improve public needed to assess the full breadth of causal links health outcomes. between environmental change, biodiversity,
¹⁵ As Carpenter et al. (2009) have noted, some drivers may affect human health without affecting biodiversity or the services it provides, or some ecosystem processes may affect drivers directly. ¹⁶ This difficulty has been attributed to the fact that causal links can be non-linear or bypass some processes altogether.
Connecting Global Priorities: Biodiversity and Human Health 43 COMSTOCK/THINKSTOCK PART II Thematic Areas in Biodiversity & Health 3. Freshwater, wetlands,
SAM PHELPS/UNHCR/ FLICKR biodiversity and human health
1. Introduction on unimproved water supplies that are believed to have high levels of pathogen contamination The centrality of water to human and ecosystem (WHO 2013; WHO and UNICEF 2012; Prüss- health is readily apparent, yet often neglected. Ustün et al. 2014).¹ This reinforces the ongoing Manipulating and adapting to changes in water importance of ensuring freshwater quality and levels – dealing with water scarcity, flooding or supply from natural ecosystems for the control storms – has been instrumental for civilizational and regulation of waterborne and water-related survival, and this will continue as climate change diseases, in particular for the world’s poorest, proceeds. The immense demand for water posed most vulnerable populations, who already carry by modern industry, agriculture, aquaculture, a disproportionate portion of the global burden forestry, mining, energy generation and human of disease. consumption combine to exacerbate pressures on water quality and quantity. Such threats to As discussed in this chapter and in the wide freshwater and other aquatic ecosystems cannot breadth of scientific research in this area, the be viewed in isolation from their impacts on ecosystems that sustain our water resources are human health and well-being (Carr and Neary complex, and the often irreversible harm that they 2008). sustain can be linked to public health outcomes. More judicious management and use of our water In addition to direct health impacts (such as resources and aquatic ecosystems, coupled with water-related illnesses), degradation caused by improved access to clean water, sanitation and safe human activity (such as unsustainable agricultural energy sources are critical, intimately related goals practices) also affects access to sanitation, increases (and challenges). As the last section of this chapter the time invested in reaching water resources, and reiterates, these will demand the application of hinders the capacity for local food production. a holistic, cross-sectoral approach, such as the Based on recent World Health Organization ecosystem or One Health approach, and equally (WHO) estimates, some 768 million people, the integrated solutions that transcend disciplinary, majority from low-income countries, still rely sectoral and political boundaries.
¹ As defined by the WHO/UNICEF Joint Monitoring Programme for Water and Sanitation (Prüss-Ustün et al. 2014).
46 Connecting Global Priorities: Biodiversity and Human Health 2. Water resources: an essential bacteria, cryptosporidium, fungal pathogens) ecosystem service of water resources, and preventing salinization (Cardinale et al. 2012; CBD 2012). Analyses of Freshwater is a provisioning ecosystem service flood frequency in low-income countries have (MA, 2005a) and is important for several aspects found that the slope, amount of natural/non- of human health. All terrestrial freshwater natural forest cover and degraded area explain ecosystems, forests, wetlands, soil and mountain 65% of variation in flood frequency (Bradshaw et ecosystems play a role in underpinning the water al. 2007), and is linked to the number of people cycle, including regulating nutrient cycling and displaced and killed by such events, though soil erosion (Russi et al. 2012; Coates and Smith associations with larger flooding events linked to 2012), and managing pollution (Schwarzenbach et extreme weather are not conclusive (van Dijk et al. al. 2010; Horwitz et al. 2012). Many of the world’s 2009). This has implications for the development major rivers begin in mountain highlands, and of improved disaster risk reduction strategies (see more than half of the human population relies on also the chapter on resilience and disaster risk fresh water flowing from these areas (MA 2005b). reduction in Part III of this volume). It has been estimated that mountain ecosystems contribute between 32% and 63% to the mean It is widely accepted that water purification services annual river basin discharge, and supply around provided by biodiverse ecosystems underpin 95% of the total annual river discharge in some water quality, which is a universal requirement arid areas (Viviroli et al. 2003). Biodiversity is for maintaining human health. For example, the central to the ecological health of mountain hydrological, chemical and biological processes of ecosystems and river basins. wetlands significantly ameliorate water quality.² Groundwater is also a major source of water for Water and soil conservation services of forests drinking and/or irrigation but also a potential vary among biomes, landscapes and forest types. source of pathogenic microorganisms (Gerba In many regions, forests improve surface soil and Smith 2005; Lapworth et al. 2012). While protection and enhance soil infiltration, prevent biodiversity, including species diversity, may be a soil erosion and landslides, protect riverbanks source of disease emergence, in some cases, high against abrasion, and regulate microclimate species diversity in vertebrate hosts of vectors can (CBD 2012; Naiman and Décamps 1997). For play a beneficial role by impeding dominance by example, cloud forests can increase dry season particular species that act as key reservoirs of the flow and total water yield (see e.g. Hamilton pathogens (Ostfeld and Keesing 2000).³ 1995; Bruijnzeel 2004; Balmford and Bond 2005). Natural forests enhance river water quality by 2.1 The role of species diversity preventing soil erosion, trapping sediments, and removing nutrient and chemical pollutants, The loss of species hinders the ability of reducing microbial contamination (fecal coliform ecosystems to provide ecosystem services such
² For example, based on a thorough review of 169 studies examining hydrological functions of wetlands, Bullock and Acreman (2003) reported that (1) wetlands significantly influence the global hydrological cycle, (2) wetland functions vary among different wetland hydrological types, (3) floodplain wetlands reduce or delay floods, (4) some wetlands in the headwaters of rivers increase flood flow volumes, sometimes increasing flood peaks, (5) some wetlands increase river flows during the dry season, and (6) some wetlands, such as floodplain wetlands hydrologically connected to aquifers, recharge groundwater when flooded. Mangrove wetlands are also effective in removing heavy metals from water (Marchand et al. 2012). ³ Increased species diversity can reduce disease risk in some cases by regulating the abundance of an important host species (Rudolf & Antonovics 2005), or by redistributing vector meals in the case of vector-borne diseases (Van Buskirk and Ostfeld 1995; Norman et al. 1999; LoGiudice et al. 2003). In practice, transmission reduction can occur when adding species reduces pathogen load or the pathogen’s titre (i.e. the concentration of an antibody, as determined by finding the highest dilution at which it is still able to cause agglutination of the antigen) within the host (Keesing et al. 2006). For a more thorough review on the role of biodiversity in disease emergence, see the chapter on infectious diseases in this volume.
Connecting Global Priorities: Biodiversity and Human Health 47 as the filtering of pollutants. Numerous scientific Mazepova 1998) and plant species enhance the studies have shown that filter feeders play an purity of water. For example, Moringa oleifera seeds important role in the elimination of suspended and Maerua decumbens roots are used for clarifying particles from water and its purification (Newell and disinfecting water in Kenya (PACN 2010). Yet, 2004; Ostroumov 2005, 2006). Bivalve molluscs habitat degradation and biodiversity loss often of both marine and freshwater environments continue to hamper the ability of ecosystems to have the ability to filtrate large amounts of water provide water purification services and to decrease (Newell 2004; Ostroumov 2005). It has also been the quality of water available.⁵ found that molluscs may reduce pharmaceuticals and drugs of abuse from urban sewage (Binellia 2.2 Social costs of impaired water et al. 2014). The mussel species Diplodon chilensis quality chilensis (Gray 1828), Hyriidae, native of Chilean and Argentinean freshwater habitats, play a key Ecosystems play an essential role in regulating role in reducing eutrophication, both by reducing water quantity and quality, which are also primary factors affecting food production, essential for total phosphorus (PO4 and NH4) by about one order of magnitude and also by controlling sustaining human health and livelihoods. For phytoplankton densities. These mussels also example, wetlands directly support the health contribute to increasing bottom heterogeneity and livelihood of many people worldwide through and macrocrustacean abundance, and attract the provision of important food items such as predatory fish. Thus, the mussels provide energy rice and fish (Horwitz et al. 2012). There are and a nutrient source to the benthic and pelagic multiple mental health benefits of experiencing a food webs, contributing to more rapid recycling natural environment, including, for example, the of organic matter and nutrients (Soto and Mena contribution of spiritual and recreational values of 1999). wetlands to human psychological and social well- being (see also chapter 12 in this volume). Economic valuations of water as a habitat for freshwater species diversity have been carried out.⁴ Impaired water quality results in significant social The first estimate of the global values of ecosystem and economic costs, and ecosystem degradation goods (e.g. food in the form of aquatic species), is a major cause of declines in water quality. services (e.g. waste assimilation), biodiversity Rectifying poor-quality water through artificial and cultural considerations yielded a value of US$ means (such as water treatment plants) requires 6579 x 109/year for all inland waters, exceeding substantial investment and operational costs. Left the worth of all other non-marine ecosystems untreated, poor-quality water results in massive combined (US$ 5740 x 109/year), despite the far burdens on human health, with women, children smaller extent of inland waters (Costanza et al. and the poor being the most affected. Reflecting 1997). It follows that biodiversity conservation this priority, many protected areas and special or restoration can be an effective, efficient and reserves have also been established to protect cost–effective way of improving water quality water supplies, including fresh water for urban and wastewater management. Plant and algae areas (Blumenfeld et al. 2009). For example, 33 of species diversity enhances the uptake of nutrient 105 of the world’s largest cities source their clean pollutants from water and soil (e.g. Cardinale et water from protected areas (Ervin et al. 2010; see al. 2012), and some animals (such as copepod also Box 1). Epischura baikalensis in Lake Baikal, Russia; see
⁴ Some of these studies also indicate that the services that such diversity provides are an essential driver of behavioural change. See the section on behavioural change in the chapter on Sustainable Development Goals and the post-2015 Development Agenda in Part III of this volume. ⁵ Moreover, while water quality can be monitored through chemical analysis, long-term trends in freshwater ecosystems may be best monitored using the diversity of aquatic organisms (such as benthic invertebrates) as proxy indicators for measuring water quality and ecosystem health.
48 Connecting Global Priorities: Biodiversity and Human Health Box 1. The Catskills: an ecosystem service for over 10 million people
The Catskills mountains were named a forest reserve in 1885 and are one of several important examples of the fact that cost–e ective biodiversity and health co-bene ts are achievable. In the three decades that followed the creation of the forest reserve, the high value of the life-supporting services provided by the mountains became apparent; rather than investing large sums of money on ltering water supplies, the state of New ork invested in creating reservoirs in the Catskills park, beginning with the Ashokan Reservoir in 1898. Today, the New ork watershed provides the largest un ltered water supply in the United States and provides an estimated 1.3 billion gallons of drinking water to over 10 million residents daily. To this day, water quality standards mandated by the United States (US) Environmental Protection Agency have been met without the need for water ltration services, whose estimated costs would have run into billions of US dollars. It has been estimated that New ork city avoided 6–8 billion in expenses over a 10 year period, by protecting its watersheds.
More recently, the important role of the Catskills as a breeding site for sh has also been recognized. The Catskill Center for Conservation and Development was founded in 1969, and has been advocating for the park since. To this day, the Catskills provide much of New ork State s highest- quality drinking water as well as a relaxing recreational site for tourists and locals alike. E orts to ban high-volume hydraulic fracturing for shale oil in the surrounding areas stem from concerns about its impact on water quality. There are also serious concerns about the potential of drought related to climate change having a signi cant impact on this vital ecosystem service.
Sources: Frei et al. 2002; MA 2005a; see also http://www.catskillmountainkeeper.org/no_time_to_stop_on_fracking
3. Dual threats to freshwater on infectious diseases in this volume), including ecosystems and human health neglected tropical diseases such as trachoma, onchocerciasis (Hotez and Kamath 2009), Altered waterways and human development (e.g. lymphatic filariasis (Erlanger et al. no date), or construction of dams, irrigation canals, urban guinea-worm disease (Fenwick 2006). drainage systems, encouraging settlements close to water bodies) can all provide benefits to human Freshwater ecosystems, such as rivers, lakes and communities. However, related infrastructure wetlands, face disproportionately high levels of may not only be costly to build and maintain, threats to biodiversity due largely to demands on but is also often accompanied by new risks to the water (for a recent comprehensive review of the environment (e.g. flood risk from degradation state of the world’s wetlands and their services to of coastal wetlands) and public health, including people, see Garner et al. 2015). In some regions, up emergence of disease (Horwitz et al. 2012; Myers to 95% of wetlands have been lost and two thirds and Patz, 2009).⁶ These activities can diminish of the world’s largest rivers are now moderately native biodiversity and increase waterborne or to severely fragmented by dams and reservoirs water-related illnesses, such as schistosomiasis or (UNEP 2012). Freshwater species have declined malaria (discussed in section 3; see also chapter at a rate faster than any other biome, with the
⁶ Waterborne diseases have been classified into four types: those spread through contaminated drinking water such as cholera; those linked to poor sanitation such as typhoid; those transmitted by vectors reliant on freshwater bodies for at least one stage in their life-cycles, such as malaria; and those that involve an aquatic animal to serve as an intermediate host, such as schistosomiasis (e.g. Resh 2009).
Connecting Global Priorities: Biodiversity and Human Health 49 sharpest decline in tropical freshwater biomes.⁷ hormones can lead to bioaccumulation, and have More than one third of the accessible renewable been linked to endocrine disruption (Caliman and freshwater on earth is consumptively used for Gavrilescu 2009) and reproductive dysfunction agriculture, industrial and domestic purposes (Khan et al. 2005), all of which pose dual threats (Schwarzenbach et al. 2006), which often leads to biodiversity and to the health of people who are to chemical pollution of natural water sources, a reliant on freshwater resources (see also chapter cause for major concern in many parts of the world on biodiversity, health care, and pharmaceuticals (Schwarzenbach et al. 2010). It has been estimated in this volume). As discussed in subsection 3.4, that approximately 67% of global water withdrawal other causes of bioaccumulation include human and 87% of consumptive water use (withdrawal activities such as mining. minus return flow) is for irrigation purposes (Shiklomanov 1997; see also Box 2 case study 3.1: Eutrophication, human health and on cotton). This has drained wetlands, lowered ecosystem healthƿ water tables and salinized water sources through intrusion and diminished water flows in key river Eutrophication, caused by the input of nutrients systems; some of these, such as the Colorado delta in water bodies and characterized by excessive (Glenn et al. 1996) and Yellow river, China (Chen plant and algal growth, is both a slow, naturally et al. 2003) now periodically fail to reach the sea. occurring phenomenon and a process accelerated The oceans are similarly challenged: an estimated by human activity (cultural eutrophication). The 38% decline in coral reefs has occurred since 1980, latter is caused by excessive point source (from largely as a result of climate change, which is also a single identifiable source of contaminants) and causing changes in ocean habitat and sea levels, non-point source (without a specific point of concurrent with ocean acidification (UNEP 2012). discharge) pollution; the most common causes include leaching from fertilized agricultural As discussed in the subsections that follow, threats areas, sewage from urban areas and industrial to water resources and ecosystems (both freshwater wastewater. and marine) often present equally significant threats to human health. Other human activity, The input of nutrients most commonly associated such as the use of pharmaceuticals or antibiotics, with eutrophication – phosphorus (e.g. in dam construction and mining activities also have detergents) and nitrogen (e.g. agricultural run- significant direct and indirect, albeit unintended, off) – into lakes, reservoirs, rivers and coastal consequences on water resources and public marine ecosystems, including coral reefs, have health. Ecotoxicological data on environmental been widely recognized as a major threat to both exposure to pharmaceuticals and persistent water ecosystems and human health. In freshwater substances such as anti-inflammatory drugs, environments, cultural eutrophication is known antiepileptics, beta-blockers, antidepressants, to greatly accelerate algal blooms. In marine antineoplastics, analgesics and contraceptives and estuarine systems, the enhanced inputs of indicate a range of negative impacts on freshwater phosphorus and nitrogen often result in a rise of resources, ecosystems, living organisms and, cyanobacteria and dinoflagellates. The effects of ultimately, some aspects of human health (see eutrophication include the following: Santos et al. 2010; Lapworth et al. 2012). The use of sex hormones and veterinary growth • toxic cyanobacteria poisonings (CTPs)
⁷ Based on data on the freshwater Living Planet Index (LPI), the decline in freshwater species was greater than any other biome between 1970 and 2008, although global terrestrial marine indices have also sharply declined. The freshwater LPI considers 2849 populations of 737 species of fish, birds, reptiles, amphibians and mammals found in temperate and tropical freshwater lakes, rivers and wetlands. Among them, tropical freshwater species declined more than any other biome. Data prior to 1970 are not captured due to insufficient data (WWF 2012). For further discussion on the global status of species declines, see also Global Biodiversity Outlook, fourth edition (CBD 2014). ⁸ Shaw et al. 2003; Carmichael, 2001; EEA 2005; Shaw and Lam 2007; Chorus and Bartram 1999; WHO 1999
50 Connecting Global Priorities: Biodiversity and Human Health • increased biomass of phytoplankton and Medical facilities are only one of several potential macrophyte vegetation routes of exposure to human toxicity from cyanotoxins; others include the recreational • increased biomass of consumer species use of lakes and rivers, and the consumption of drinking water, algal dietary supplements and • shifts to bloom-forming algal species that food crops, among others. In addition to Brazil, might be toxic or inedible health problems attributed to the presence of cyanotoxins in drinking water have been reported increase in blooms of gelatinous zooplankton • in a number of countries, including Australia, (marine environments) China, England, South Africa and the United States. • increased biomass of benthic and epiphytic algae 3.2 Proliferation of cyanobacteria • changes in species composition of macrophyte caused by eutrophication vegetation The discharge of nutrients in waterways can lead • decline in coral reef health and loss of coral reef to eutrophication. Under eutrophic conditions, communities nutrient loading indirectly decreases the amount of oxygen in the water and eventually eliminates • increased incidence of fish kills certain species. In oxygen-depleted water, fecal pathogens may proliferate and the risk of enteric • reduction in species diversity of harvestable disease transmission increases (Fuller et al. 1995). fish and shellfish In addition, wherever conditions of temperature, light and nutrient status are conducive, surface • water treatment and filtration problems waters may host increased growth of algae or cyanobacteria. This phenomenon is referred to • oxygen depletion as an algal or cyanobacterial bloom (see section 3.1). Problems associated with cyanobacteria • decreases in perceived aesthetic value of the are likely to increase in eutrophic areas, such as water body. those with high sewage discharge and agriculture practices (WHO 1999). Species of cyanobacteria It was found that eutrophication occurs in may produce toxins that affect the neuromuscular approximately 54% of Asia-Pacific, 53% of system and liver, and can be carcinogenic to European, 48% of North American, 41% of vertebrates, including humans. South American and 28% of African lakes. Eutrophication can cause considerable harm to Among the 14 000 species of continental algae, freshwater, marine ecosystems, and terrestrial about 2000 are cyanobacteria and 19 genera ecosystems and the life that inhabits them; produce toxins. Cyanotoxins show specific toxic these impacts can range from wild and domestic mechanisms in vertebrates, some of which animal illness and death to equally far-ranging are strong neurotoxins (anatoxin-a, anatoxin- consequences for human health. For example, a(s), saxitoxins) and others are primarily in 1996, a routine haemodialysis treatment toxic to the liver (microcystins, nodularin at a dialysis centre in Caruaru, Brazil led to an and cylindrospermopsin). Microcystins are outbreak of cyanotoxin human toxicosis. Among geographically most widely distributed in 130 patients affected, almost 90% experienced freshwaters (WHO 1999). They bioaccumulate in visual disturbances, nausea and vomiting, 100 of common aquatic vertebrates and invertebrates, them developed acute liver failure and 70 died; including fish, mussels and zooplankton (Ibelings 53 of these deaths were attributed to what is now and Chorus 2007). Cases were reported in the Latin known as the “Caruaru syndrome.” American and Carribbean region. For example, in
Connecting Global Priorities: Biodiversity and Human Health 51 UNITED NATIONS PHOTO / FOTER CC BY-NC-ND UNITED NATIONS
a hypertrophic reservoir in Argentina, if a 70 kg similarly be low if control measures are in place for person would consume 100 g of fish (Odontesthes times of bloom formation. If regular monitoring bonariensis), the equivalent of approximately of source phytoplankton is in place, waters 0.49 mg/kg body weight/day would be consumed presenting no significant cyanotoxin risk may (Cazenave et al. 2005), which is in excess of the be easily identified (see review in WHO 1999). range of the seasonal tolerable daily intake (TDI) Substantially less is known about the removal of (0.4 mg/kg/day). In Brazil, concentrations of neurotoxins and cylindrospermopsin than about microcystins in edible parts of Tilapia rendalli were microcystins, thus toxin monitoring of treatment examined during the cyanobacterial bloom season. steps and finished water is especially important. Concentrations varied between 0.0029 and 0.337 Methods such as adsorption by some types of mg/g muscle tissue. Consumption of 300 g of fish granular activated carbon and oxidation can be with this highest concentration would exceed the effective in cyanotoxin removal (WHO 1999). seasonal TDI by four times. The amount of toxin in Tilapia livers has been found to reach levels as high 3.3 Multiresistant bacteria: new as 31.1 mg/g wet weight (Freitas de Magalhães et approaches in sewage treatment al. 2001), so that in a typical meal, an adult could be exposed to hundreds of times the seasonal The use of antibiotics in hospitals, for swine and TDI. Common advice given by water authorities poultry production, and in fish farms can result is that the viscera of the fish should not be eaten, in routes of dissemination of multiresistant but caution should be exercised in all cases where bacteria and their genes of resistance into the major toxic blooms occur. environment, thus contaminating water resources and having a serious negative impact on public Where bloom formation is well characterized health. Antibiotics are widely used to protect the in terms of annual cycles, the health risk may health of humans and domesticated animals, and/
52 Connecting Global Priorities: Biodiversity and Human Health or to increase the growth rate of animals as food of organic matter, which can remobilize Hg from additives. The use of antibiotics may accelerate the soil into the food chain (Passos and Mergler the development of antibiotic resistance genes 2008). ASGM activities account for approximately (ARGs) in bacteria and other pathogens, which 12% of all gold produced worldwide (Veiga et pose health risks to humans and animals (Kemper al. 2014), and to produce 1 mg of gold, 2.5–3.5 2008; see also the chapter on health care and mg of Hg are used, of which approximately 50% impact of pharmaceuticals on biodiversity in this reaches streams and rivers as suspended sediment volume). The introduction of these new genes can (UNEP 2013). Metallic Hg is also emitted into the alter the biology of pathogens because ARGs can atmosphere as a result of ASGM activities, and is be transmitted to other species of bacteria (Heuer reduced into inorganic Hg and precipitated into et al. 2002; Tennstedt et al. 2003). Therefore, even terrestrial and aquatic ecosystems. common strains of pathogens may incorporate these genes and become resistant to antibiotics. While Hg remains in the soil, it is often in its The only way to detect multiresistant bacteria is by inorganic form, less toxic, but when it reaches performing a DNA microarray. However, this kind water courses, microorganisms may transform of procedure is not yet common in health centres. it to a more toxic form, methyl Hg (Hacon and Azevedo 2006). Methyl Hg can bioaccumulate Perhaps the most effective and direct approach in the tissue of organisms and through the food to reduce the possibility of the introduction and chain, as they are consumed by other species. It spread of ARGs is the controlled use of antibiotics can also reach human populations through fish in health protection and agriculture production. consumption (Passos and Mergler 2008). In New and effective wastewater treatment processes human populations, methyl Hg is neurotoxic and are also needed to improve removal efficiency of prenatal exposure can affect brain development, ARGs in sewage treatment plants. Additionally, even at low doses of exposure⁹. Children exposed irrigation using wastewater has to be discussed to methyl Hg may have delayed and impaired thoroughly, considering possible introduction of neurodevelopment, and exposed adults may have ARGs in the soil and groundwater (Zhang et al. impaired motor coordination, visual fields, speech 2009). and hearing (UNEP, UNICEF, WHO 2002).
Methyl Hg was found in high concentrations 3.4 Bioaccumulation: the impact of in fish and shellfish, which are also the primary mining sources of exposure to human populations (Veiga Many mining activities discharge mercury et al. 1994; Porvari 1995; Fearnside 1999). In (Hg) and methyl Hg in aquatic ecosystems, the Guri hydroelectric reservoir in Venezuela, thereby contaminating water, ecosystems and from 219 fish samples, 93 specimens showed aquatic species with a correspondingly negative levels above 0.5 ppm Hg and up to 90% of the repercussion on human health. (For a recent most appreciated piscivore fish in the region review of freshwater fish species in Africa please (Rhaphiodon vulpinus) showed average Hg levels see Hannah et al. 2015.) of 2.7 ppm (0.17–8.25 ppm) (UNIDO 1996) – higher than those found in detritivorous and There are many ways by which Hg can reach herbivorous fish species. Contamination through aquatic ecosystems. Major anthropogenic sources methyl Hg is particularly high in the Amazonian are artisanal and small-scale gold-mining (ASGM) region. Several Amazonian communities have activities, which use Hg to amalgamate with gold Hg levels considered to be critical for optimal (Veiga et al. 2014), and deforestation and burning neurological development. Dietary Hg intake has
⁹ For a summary of the health impacts associated with mercury exposure and the identification of potential pathways for strategic action see also World Health Organization: http://www.who.int/phe/news/Mercury-flyer.pdf. For guidance on assessing the risk of mercury exposure to humans see also WHO-UNEP (2008), available at http://www.who.int/foodsafety/ publications/chem/mercuryexposure.pdf?ua=1
Connecting Global Priorities: Biodiversity and Human Health 53 been estimated to be 1–2 μg/kg/day, considerably Natural vegetation cover in buffers along rivers is higher than the WHO recommendation (0.23 μg/ critical to the regulation of water flow, retention of kg/day) (Passos and Mergler 2008). nutrients, and capture of pollutants and sediments across landscapes (reviewed in Osborne and The reduction or elimination of Hg use in Kovacic 1993). The removal of trees and natural ASGM has been receiving widespread attention habitats in landscapes affects soil directly, as well (Veiga 2014). Less damaging options include as the quantity and quality of water draining amalgamating a gold concentrate rather than the from agricultural systems. Riparian buffers of whole ore and using “mercury-free artisanal gold”, non-crop vegetation are widely recommended as in which gold is isolated by centrifuges and the a tool for removing non-point source pollutants, gangue materials magnetically removed (Drace particularly nutrients (nitrates, phosphorus, et al. 2012). Awareness and education about Hg potassium) from agricultural areas, especially poisoning in ASGM communities is also essential those carried by surface run-off (Lee et al. 2003; to ensuring adherence to such changes in ASGM Brüsch and Nilsson 1993; Daniel and Gilliam technology. 1996; Glandon et al. 1981; Nakamura et al. 2001). In field studies, even buffers of switchgrass along 4. Impacts of agriculture on water fields removed 95% of the sediment, 80% of the ecosystems and human health total nitrogen (N), 62% of the nitrate nitrogen (NO3-N), 78% of the total phosphorus (P), and
Unsustainable agricultural practices have 58% of the phosphate phosphorus (PO4-P). If the significant impacts on human health, and water buffer included woody species, it removed 97% pollution from fertilizers, pesticides and herbicides of the sediment, 94% of the total N, 85% of the
remains a serious problem (see the chapter on NO3-N, 91% of the total P, and 80% of the PO4-P agricultural biodiversity and food security in in the run-off (Lee et al. 2003). this volume). Better use of ecosystem services, underpinned by biodiversity, in agricultural Nutrient run-off from agricultural sources into production systems provides considerable waterways has been blamed for the production of opportunities to reverse these impacts on health hypoxia, popularly termed (aquatic) “dead zones” while simultaneously improving food security. (Diaz 2001). These destroy local fisheries in many coastal areas, which communities rely on for the Agriculture accounts for about 70% of global intake of protein and other nutrients. Dead zones water use, and physical water scarcity is already a have now been reported in more than 400 systems, problem for more than 1.6 billion people (IWMI affecting a total area of more than 245 000 2007). It is increasingly recognized that the square kilometres (Diaz and Rosenburg 2008; management of land and water are inextricably see Figure 1). These are concentrated along the linked (e.g. DEFRA 2004). In England, for eastern seaboard of North America, and European example, up to 75% of sediment loading in rivers and Japanese coastlines, where human ecological can be attributed to agriculture, while 60% of footprints and agriculture intensities are highest nitrate pollution and 25% of phosphates in surface (Diaz and Rosenburg 2008, see Figure 1). waters originates from agriculture (DEFRA 2007). Agricultural practices can also contribute to the Agricultural practice and its demand for water spread of water-related and waterborne disease. have reduced both the amount and quality of For example, significant E. coli loads have been drinking water available for human consumption. found in run-off from land grazed by cattle and At the same time, lack of irrigation in many low- treated with livestock wastes (Oliver et al. 2005), income countries is a leading cause of poor crop all of which impact the quality of water for human production and yield gaps (Lobell et al. 2009). By consumption and use. 2002, irrigated agricultural land comprised less than one fifth of all cropped area but produced 40–45% of the world’s food (Döll and Siebert
54 Connecting Global Priorities: Biodiversity and Human Health 2002). Integrated water management practices reduce the negative impacts of current water use that maintain and use biodiversity to support practices on human health and contribute to its ecosystem services that improve water use improvement. efficiency and water quality will be needed to
ǡǤǢǰǭǠɻ Eutrophication-associated dead zones, 2008
Hypoxic system Human footprint 0 - 1 1 - 10 10 - 20 20 - 30 30 - 40 40 - 60 60 - 80 80 - 100
Global distribution of over 400 systems that have scienti cally reported accounts of being eutrophication-associated dead zones. Source: Diaz and Rosenberg 2008
Box 2. Case study: Water consumption and cotton production
Cotton is a particularly important global crop and the most important natural bre used in textile industries worldwide, accounting for 40% of textile production, but it is also a major consumer of water: over half of all cotton production is dependent on heavy irrigation (Soth et al 1999; Chapagain 2006). In the period 1960–2000, an environmental disaster unfolded as the Aral Sea in Central Asia lost approximately 60% of its area and 80% of its volume (Glantz 1998; Pereira et al. 2002) as a result of the annual withdrawal of water from its main feeder rivers, the Amu Darya and the Syr Darya, for cotton agriculture in the desert (Cosgrove and Rijsberman 2014). This depletion of water a ected local sheries and livelihoods (Micklin 2007), as well as water quality both from harvesting and processing (Bednar et al. 2002; Chapagain et al. 2006). As cotton is a global commodity, its consumption takes place in areas remote from its growth. One study concluded that about 84% of the “water footprint” of cotton consumption in Europe is located outside the continent, with “major impacts in India and Uzbekistan” (Chapagain et al. 2006). E orts to improve the production of cotton have focused on the development of transgenic Bacillus thuringiensis (Bt) cotton, which reduces insecticide use (Cattaneo et al. 2006), as well as improvements in water e ciency through drip irrigation furrow, and other e orts to reduce the negative environmental and human health impacts. Despite these e orts, cotton production, itself a source of agricultural biodiversity reduction, remains a major consumer of global freshwater with a pronounced impact on freshwater biodiversity.
* Whereas the term “ecological footprint” denotes the area (ha) needed to sustain a population, the “water footprint” rep- resents the water volume (cubic metres per year) required, including dilution water necessary to restore polluted water to internationally agreed water quality standards.
Connecting Global Priorities: Biodiversity and Human Health 55 5. Waterborne and water-related of them among young children (Prüss-Üstün et al. diseases 2008; WHO 2003a).¹² Long before the advent of modern medical care, Factors that have been found to increase the industrialized countries decreased their levels of water- incidence of waterborne diseases include related disease through good water management. urbanization and high population densities Yet, even in these countries, outbreaks of waterborne of people, agriculture and industry (Patz et al. disease continue to occur, sometimes with lethal 2004). Habitat destruction or modification also consequences. In developing countries, water-related plays a major role. For example, dam-related disease blights the lives of the poor. Gro Harlem reservoir construction increases the prevalence Brundtland, former WHO Director-General, 2001. and intensity of human schistosomiasis in Africa (e.g. N’Goran et al. 1997; Zakhary 1997) and Surface freshwaters are among the most altered elsewhere (Myers and Patz 2009), as described in ecosystems on the planet and, coupled with Box 3. Climate change and the spread of aquatic associated biodiversity loss, have been linked invasive species (see section 5.1) may facilitate to increased incidence of infectious diseases, transmission of human pathogens (such as the including waterborne illnesses (Carpenter et al. Asian tiger mosquito Aedes albopictus) and can 2011; see also the chapter on infectious diseases transmit viruses such as dengue, LaCrosse, West in this volume for a detailed discussion). Although Nile and chikungunya (Benedict and Levine 2007). the global disease burden of many formerly devastating waterborne illnesses (e.g. cholera, A strong relationship between the human typhoid fever) has declined considerably, others development index (HDI), access to drinking continue to affect a significant proportion of the water services and sanitation with mortality by global population, especially in the world’s lowest- diarrhoea was found in some parts of the world, income regions, such as sub-Saharan Africa, where particularly low-income countries. Almost half the highest concentration of poverty occurs (Hotez of the population in these countries is at risk and Kamath 2009). of exposure to waterborne diseases, including gastroenteric diseases such as dysentery, The presence of pathogenic (disease-causing) giardiasis, hepatitis A, rotavirus, typhoid fever and microorganisms in freshwater can lead to the cholera. Less economically developed countries transmission of waterborne diseases,¹⁰ many of such as Haiti, for example, had the lowest water which cause diarrhoeal illness, a leading cause of and sanitation coverage levels, coupled with the mortality in children under 5 years of age, and lowest HDI values and highest child mortality among the most prevalent waterborne illnesses, rates, in contrast to Chile, Costa Rica, Cuba and particularly in low- and middle-income countries Uruguay, among others, which had higher values (Prüss-Ustün et al. 2014; WHO 2013; WHO and and coverage (PAHO 2012). UNICEF 2012; UNESCO 2009; Prüss-Üstün and Corvalán 2006).¹¹ Unsafe drinking water itself Human alteration of hydrological regimes has accounts for 88% of diarrhoeal disease worldwide often been motivated by concerns for human (including cholera, typhoid and dysentery) and health and well-being (Myers et al. 2013). While results in 1.5 million deaths each year, the majority altered waterways (e.g. dams, irrigation canals, urban drainage systems) have indeed provided
¹⁰ The contamination of surface waters with fecal material from humans, livestock or wildlife has been identified as an important (albeit not exclusive) pathway for the transmission of waterborne diseases (Prüss-Üstün and Corvalán 2006; US EPA 2003; Ragosta 2010). ¹¹ See also http://www.who.int/mediacentre/factsheets/fs330/en/; http://www.cdc.gov/healthywater/wash_diseases.html ¹² Children under 5 years of age living in poor dwellings with inadequate access to health services are the most susceptible to diarrhoeal disease and account for the overwhelming majority of all deaths attributed to these diseases (WHO 2004). Relatively little is known about the pathogens that account for diarrhoeal disease themselves (Yongsi 2010).
56 Connecting Global Priorities: Biodiversity and Human Health valuable benefits to human communities (e.g. vectors of schistosomiasis. This disease affects energy, employment, access to food), they are over 200 million people worldwide, of which 88 costly to build and maintain, have frequently million are under 15 years of age, with the heaviest been accompanied by unintended consequences to infections being reported in the 10–14 years’ ecosystems¹³ and have had negative repercussions age group in Africa and South America (UNEP, on public health, in some cases considerably UNICEF & WHO 2002). increasing the availability of habitats for disease organisms and their vectors (de Moor 1994) Other species, such as aquatic plants, are also and exacerbating waterborne disease outbreaks affected by shifting environmental conditions, (Dudgeon et al. 2006; Hotez and Kamath 2009; which in turn may favour mosquito breeding, Myers et al. 2014). including mosquitoes of the genus Anopheles, potential vectors of a protozoan – genus It has been estimated that some 2.3 billion people Plasmodium – causing malaria (Thiengo et al. suffer from diseases related to water, and diseases 2005). Many studies have reported the increase transmitted by freshwater organisms kill an in malaria cases after the construction of large estimated 5 million people per year. Unsustainably dams. From the Chiapas hydroelectric power managed ecosystems, such as wetlands, may plant in Mexico to Itaipu Binacional in Brazil/ harbour waterborne and vector-borne pathogens Paraguay, thousands of malaria cases were linked such as plasmodium and human schistosoma; the to dam construction (Couto 1996). In South latter is described in Box 3 (Horwitz et al. 2012; America, almost 60% of all reservoirs were built Dale and Connelly 2012; Dale and Knight 2008; since the 1980s. Prevalence of other diseases Fenwick 2006). may also increase with river damming. In the area of influence of the Yacyreta dam (Paraná The habitat degradation that often accompanies River, Argentina/Paraguay), Culicoides paraensis human development activities, and corresponding mosquitoes were found (Ronderos et al. 2003). simplification of natural species assemblages, have These are known vectors of Oropouche fever – been found to foster the proliferation of disease which registered epidemics in many urban centres vectors. The maintenance of natural freshwater in the Pará State of Brazil (Barros 1990). communities and ecosystem integrity, where possible, may correspondingly contribute to a Biological and chemical threats (e.g. agricultural reduction in conditions for the transmission of run-off, pharmaceuticals) to water resources, diseases, including those related to water (Dudgeon as well as the development of water-related et al. 2006). The development of dams and infrastructure and urbanization, have also had irrigation projects, for example, can contribute to their share of detrimental impacts on both expanding habitats for mosquitoes, aquatic snails biodiversity and human health by diminishing and flies, which can spread disease among resettled native biodiversity and sometimes increasing the agricultural populations. River damming changes potential for waterborne illnesses. physical and chemical conditions, altering the original biodiversity (Tundisi et al. 2002). Reduced The global community has widely acknowledged water current creates favourable conditions for the importance of access to clean water, sanitation molluscs from the genus Biomphalaria, potential and hygiene as critical development interventions
¹³ Human activities can hamper the ecological balance of wetlands and thereby alter existing disease dynamics or introduce novel disease problems (Horwitz et al. 2012). For example, flood risk may also increase as a result of degradation of coastal wetlands, demonstrated with Hurricane Katrina’s impact on New Orleans, and extant deforestation exacerbated the health impact of the 2010 earthquake in Haiti.
Connecting Global Priorities: Biodiversity and Human Health 57 in several goals and targets of the Millennium life-supporting services that sustain our water Development Goals (MDGs).¹⁴ It was estimated (and other) resources. that over one sixth¹⁵ of the world’s population did not have access to safe water at the time The provision of clean water and sanitation to the the MDGs¹⁶ were adopted (Prüss-Üstün et al. world’s poor, who are particularly vulnerable and 2004). While considerable progress had been ill-equipped to cope with further loss of ecosystem achieved by 2010,¹⁷ much work is still needed to services, garners health benefits. The sustainable meet global targets, particularly in low-income management of resources can also alleviate pres- regions, including sub-Saharan Africa (WHO sures caused by the unsustainable use of wetland and UNICEF 2012). Subjacent to the fulfilment and other ecosystems, reducing waste flows while of these objectives is the need to sustainably also improving the overall quality of fresh and manage the ecosystems that provide the critical coastal waters essential to health and well-being.
Box 3. Ecosystem disturbance and waterborne disease: the case of schistosomiasis
While ecosystems can act as disease reservoirs, there is abundant scienti c literature to support the claim that these cannot be viewed in isolation from the human activity that alters them. Schistosomiasis is a waterborne disease that a ects some 200 million people worldwide. It can cause grave damage to internal tissues, including the liver, intestines and bladder, and has been found to undermine growth and development in children.
While schistosomiasis has been closely related to ecosystem disruption and the unsustainable use of biological resources, it is also sustained in a setting of poverty. A systematic review of schistosomiasis and water resource development carried out by Steinmann et al. (2006) estimated that among 200 million infected, an estimated 93% (192 million cases) occur in sub-Saharan Africa, including 29 million in Nigeria, 19 million in the United Republic of Tanzania, and 15 million each in the Democratic Republic of the Congo and Ghana. Approximately 76% of the population in sub-Saharan Africa lives near rivers, lakes and other contaminated water bodies.
Schistosomiasis is caused by parasitic worms (Schisotoma spp.), which spend a portion of their life- cycle in some species of freshwater snails that act as intermediate hosts for the disease. People become infected with the parasitic worms when they enter contaminated waters and the parasitic worms leave their host to penetrate human skin, thus infecting the subject. In Lake Malawi, it was found that over shing caused an increase in abundance of Bulinus nyassanus, a snail species that acts as the intermediate host of the schistosome parasite.
¹⁴ See MDG 7 (Ensure environmental sustainability) Targets 9, 10, 11; MDG 4 (Reduce child mortality) Target 5; MDG 6 (Combat HIV/AIDS, malaria, and other diseases) Target 8. ¹⁵ It is estimated that 1.1 billion people did not have access to safe drinking water and 2.4 billion lacked access to improved sanitation when these goals and targets were first adopted. ¹⁶ When the MDGs were first adopted, approximately 3.1% of annual deaths (1.7 million) and 3.7% of the annual health burden of disability-adjusted life years (DALYs) worldwide (54.2 million) were attributed to unsafe water, sanitation and hygiene, all of them in low-income countries and 90% of them in children (WHO 2003). Major enteric pathogens in affected children include: rotavirus, Campylobacter jejuni, enterotoxigenic Escherichia coli, Shigella spp. and Vibrio cholerae O1, and potentially enteropathogenic E. coli, Aeromonas spp., V. cholerae 0139, enterotoxigenic Bacteroides fragilis, Clostridium difficile and Cryptosporidium parvum (Ashbolt 2004; WHO 2003a). ¹⁷ By 2010, some 884 million people still did not use improved sources of drinking water (WHO 2010a). Additionally, 2.6 billion people did not use improved sanitation.
58 Connecting Global Priorities: Biodiversity and Human Health In Cameroon, schistosomiasis has been associated with an increase in deforestation. The increase in the amount of sunlight penetration, altered water rates and ow levels, and increase in vegetation growth caused by deforestation altered the ecology of freshwater snail populations in the area. Bulinus truncatus, a competent host for the parasitic worm Schistosoma haematobium (responsible for an estimated two thirds of all schistosoma infections in sub-Saharan Africa and an important cause of severe urinary tract disease), displaced another type of freshwater snail, Bulinus forskalii, which itself hosted a non-pathogenic schistosome but was less able to thrive in cleared habitat.
In Kenya, the prevalence of urinary schistosomiasis in children rose to a staggering 70% ten years after the start of the Hola irrigation project (prevalence was 0% prior to the start of the project). The irrigation project led to the introduction of a new snail vector well suited to the altered environment. The prevalence of schistosomiasis further increased to 90% by 1982. (Malaria is another disease that has been closely associated with the construction of dams and irrigation projects.)
In the Nile Delta of Egypt, dam construction in 1965 also led to an increase in schistosomiasis by increasing the habitat for Bulinus truncates, leading to an increase of almost 20% in the 1980s from 6% prior to dam construction. The increase in disease prevalence was even greater in other parts of the country.
Sources: Myers and Patz 2009 (and references therein); Evers 2006; Molyneux et al. 2008; Steinmann et al. 2006; Hotez and Kamath 2009.
5.1 Aquatic invasive alien species that eutrophication also played a role in the mass extinction event recorded by observers in Lake Invasive alien species (IAS) are a major threat to Victoria, and that the Nile perch is now on the biodiversity (Simberloff et al. 2005; McGeoch et decline (Stearns and Stearns 2010; Goudswaard al. 2010). Aquatic invasive species are among the et al. 2008). While the introduction of alien most pernicious, often travelling across the globe species may sometimes be beneficial, the case of before introduction. While some introductions are the Nile perch remains a very good example of purposeful, such as the introduction of the Nile how irreparable harm can be done to a complex perch (Lates niloticus) to Lake Victoria, which has ecosystem and why commercial introductions caused disastrous and irreparable harm, many should be viewed with the utmost caution for others are incidental. The perch was introduced potential consequences.¹⁸ for commercial reasons, and it proceeded to dominate the lake and led to the extinction of In contrast, many aquatic invasives have arrived up to 200 species of endemic haplochromine after surreptitiously travelling on cargo ships and cichlids (Goldschmidt et al. 1993). Recent oil tankers, which use ballast water to balance evidence suggests that there has been some their hulls.¹⁹ The zebra mussel worked its way recovery of aquatic biodiversity in the area, and into the North American Great Lakes via Russia
¹⁸ Invasive species Limnoperna fortunei (Dunker 1857), Mytilidae, is considered as a major problem for hydroelectrical power plants because of their high growth rates, which obstruct the pipes. However, their filtering rates are among the highest for suspension-feeding bivalves, reaching as high as 125–350 ml individual–1 h–1. The high filtration rates, associated with the high densities of this mollusc (up to over 200 000 ind m–2) in the Paraná watershed – where there are many dams, including Itaipu Binacional, one of the largest in the world – suggest that its environmental impact may be swiftly changing ecological conditions in the areas colonized, which include four countries, Brazil, Paraguay, Uruguay and Argentina (Sylvester et al. 2005). ¹⁹ Other means of accidental introduction include pet, aquaculture and aquarium releases or escapes, seaway canals, and even irresponsible research activities.
Connecting Global Priorities: Biodiversity and Human Health 59 in 1986, while the comb jelly went in the opposite on struggling native species populations, further direction, from the United States (US) to the reinforcing the spread of aquatic IAS through Caspian Sea, with devastating impacts on fisheries common vectors such as ship traffic and tourism.²² there (Chivian and Bernstein 2008: 49). The zebra For example, melting sea ice opens new vectors for mussel has had a complex impact on the water bioinvasion in the Arctic (and indeed, melting ice quality of the Great Lakes. While these bivalves can itself can release previously unknown pathogens, give lake water a clearer appearance as they filter locked into ice formations for thousands of years, various particles, including some forms of algae, into the Arctic environment). Increasing levels of they also consume phytoplankton (the building photo-degraded microplastic can also serve as a block of the marine food system), and they give vector for microbial communities (Zettler et al. harmful blue–green algae a competitive advantage, 2013). contributing to new dead zone growth.²⁰ Ricciardi (2006) estimated that one new species had been While the impact of IAS on biodiversity and discovered in the North American Great Lakes ecosystems is well documented (e.g. Charles every 28 weeks during the 1990s; while Cohen 2007), resultant impacts on human health are and Carlton (1998) found even higher rates an important area for further research (see Pysek of introduction in the San Francisco Bay area. and Richardson 2010). Deleterious waterborne International efforts to prevent ballast water- pathogens, such as those that cause cholera, are related introductions, through the International often classified as invasive species (see the chapter Maritime Organization and others, are having on infectious diseases in this volume). Other some impact, but this remains a serious focus of aquatic invasive species, such as the zebra mussel concern. Plants can be aquatic invasive species described above, not only disrupt local food as well: witness the water hyacinth, Eichhornia security networks but can also act as causative crassipes, which spreads over lake surfaces, choking agents of harmful algal blooms (Hallegraeff 1998; local vegetation and reducing oxygen availability; Coetzee and Hill 2012), threaten the availability it is a major hindrance in Africa in particular, of clean water supplies, and pose other significant though it does appear to have some natural limits health threats (McNeely 2001). Invasive bivalves to its cyclical spread (Albright et al. 2004).²¹ can clog machinery vital for the operation of energy plants and well as fishing boat equipment. Climate change will further exacerbate the problem Water hyacinth (Eichhornia crossipes) can make of aquatic invasive species as temperatures small-scale freshwater fishing next to impossible, increase and the range of invasive species, such directly lowering food security and nutrition levels as zebra mussels and Asian carp, are extended. for local communities. Moreover, its introduction Another example is the European green crab, in Lake Victoria has also been found to contribute harmful to native species in the US and parts of to the spread of waterborne diseases (Pejchar and Africa and Australia; it has been slow to spread Mooney 2009 and reference therein). Efforts to northward because of colder water temperatures, eradicate aquatic IAS can also carry health hazards but this is slowly changing with global warming if they employ lampricides and other agents that (Floyd and Williams 2004). In some cases, climate can contaminate water supplies (though sea change will join invasive species as major stressors lamprey eradication efforts in North America
²⁰ See http://www.ec.gc.ca/inre-nwri/default.asp?lang=En&n=832CDC7B&xsl=articlesservices,viewfull&po=0E367B85. The relationship with climate change is also complex: warmer temperatures will extend the range northward; and zebra mussels release carbon dioxide into the aquatic environment. ²¹ For a recent discussion on the impact of water hyacinth in South Africa, see for example Coetzee et al. (2014), and for a discussion on the role of eutrophication in its biological control, see Coetzee and Hill (2012). ²² As a major EPA report suggested in 2008, in order “to effectively prevent invasions that might result from or be influenced by climate-change factors, a first step should be to identify specific aquatic invasive species threats, including new pathways and vectors, which may result as environmental conditions such as water and air temperatures, precipitation patterns, or sea levels change” (EPA 2008:61).
60 Connecting Global Priorities: Biodiversity and Human Health have been relatively successful with limited on Water concluded that climate change would controversy). Moreover, the losses posed by IAS have multiple impacts, including: can be harmful to the well-being of communities whose sense of place may be disrupted in areas • physical changes such as increased water affected by IAS (McNeely 2001). It is vital that temperature, reduced river and lake ice cover, efforts are made to avoid introductions whenever more stable vertical stratification and less mixing possible, and to employ the precautionary of water of deep-water lakes, and changes in water principle when contemplating future purposeful discharge, affecting water level and retention time; introductions. • chemical changes, such as increased nutrient concentrations and water colour, and decreased 6. Ways forward and additional oxygen content (DOC); considerations • biological changes, including northwards It is clear that healthy freshwater systems migration of species and alteration of habitats, are central to the protection of biodiversity affecting the structure and functioning of as well as to the promotion of human health freshwater ecosystems (European Topic Centre and well-being. It is also evident that there are on Water 2010: 5) severe threats to water security and ecosystem health; and that waterborne diseases, the loss It is clear that all of these changes will affect human of aquatic biodiversity, and the disruption of security in terms of our physical and emotional complex ecosystems represent major public connections with water, and the ecosystem health challenges. A concerted effort to conserve services provided by aquatic ecosystems. We will freshwater resources is necessary on a global need to adapt to them, but we can also be more scale. While this chapter has focused primarily proactive by promoting biodiversity conservation on freshwater systems, it is equally apparent and restoration. that oceans and related biodiversity face threats from pollution, climate change, coral bleaching, Water resources will remain central to human acidification and other anthropocentric factors, and community development. The biodiversity– and that an international effort to conserve them health nexus is readily apparent in this context. is vital (Stoett 2012:107–28). These impacts However, much remains to be done regarding the extend to human health, an area that clearly management and equitable use of water resources, merits greater scientific attention. The European including preventive measures to avoid increased Marine Board recently published a position paper waterborne disease and aquatic invasive species. to this effect on “Linking oceans and human The WHO Guidelines for drinking-water quality health: a strategic research priority for Europe”,²³ establish a basis for the pursuit of a healthier which highlights the substantive and complex human species (WHO 2010b). Recognition of interactions between the marine environment the key role played by biodiversity in freshwater and human health and well-being (Flemming et systems is an important element in that pursuit al. 2014). as well. Recent laboratory research suggests that there is a positive correlation between species Moreover, we are only beginning to understand diversity and the ability of water systems to filter the impact climate change will have on aquatic nutrient pollutants such as nitrate (Cardinale ecosystems and human health (see the chapter 2011) as well as pharmaceuticals (Binellia et on climate change in this volume). In a recent al. 2014). More than ever, the biodiversity and background report written for the European global public health communities, including key Environmental Agency, the European Topic Centre decision-makers and private sector actors, need to work together towards a healthier blue planet.
²³ http://www.marineboard.eu/images/publications/Oceans%20and%20Human%20Health-214.pdf
Connecting Global Priorities: Biodiversity and Human Health 61 Some meaningful (but by no means exhaustive) greenhouse gas emissions should receive considerations include the following: extra attention, given the centrality of water biodiversity to human health. This calls for more We must take stock of our ecological capital in scientific research, including taxonomic studies ways that will benefit human health. Water and focusing on the use of bioindicators to assess other ecosystem services must be linked to broader ecosystem condition (Buss et al. 2015), and more frameworks that consider public health concerns studies linking the impacts of biodiversity loss on within broader ecosystem restoration and human health, as well as serious regulatory policy conservation frameworks, such as the ecosystem development. or One Health approach. Knowledge exchange and cross-sectoral collaboration will be critical to share The impact of water quality and quantity on and mutually learn from experiences. human health is one of several critical areas described in this volume, which underscores the The Ramsar Convention on Wetlands is a critical need to develop robust, cross-sectoral integrated instrument in the pursuit of water security. As of approaches, such as the ecosystem or One Health early 2015, 2186 sites, encompassing 208 449 277 approach to water management and to the hectares of surface area, have been classified as broader management of ecosystems (including wetlands of international importance. The Ramsar agroecosystems). Researchers, policy-makers and Convention, in force since 1975, advocates the those that manage natural resources must also “wise use” of wetlands, defined as “the maintenance work to compile and share regionally specific data of their ecological character, achieved through the on how functional metrics vary over space and implementation of ecosystem approaches, within time (Palmer and Febria 2012) and produce a more the context of sustainable development”.²⁴ composite idea of related water footprints (see Box 2 on cotton production). Applying a holistic The pollution of freshwater lakes and the oceans framework to water and food security, and other must be halted to protect their indigenous critical themes at the biodiversity–health nexus, biodiversity. Micro-plastics are a particularly makes it possible to manage ecosystems (including pernicious pollutant, harming wildlife as they water and agroecosystems) that are more resilient, enter the food chain and providing vectors for sustainable and productive, that remain productive invasive species. International efforts to stop the in the long term, and that yield a wide range of pollution and clean oceans, lakes and rivers will ecosystem services. A socioecological perspective be pivotal in the near future if we are to avoid will further ensure that vulnerable populations the further development of what scientists have most affected by the global disease burden and referred to as the “plastisphere” (Zettler et al. ecosystem degradation are also considered. These 2013). considerations will be imperative as we move from the MDGs toward the Sustainable Development The impact of climate change on water biodiversity Goals and the post-2015 Development Agenda. must be closely monitored and efforts to reduce
²⁴ http://www.ramsar.org/cda/en/ramsar-home/main/ramsar/1_4000_0
62 Connecting Global Priorities: Biodiversity and Human Health 4. Biodiversity, air quality and
UNDP BANGLADESH / FLICKR human health
1. Introduction million in 2012 (WHO 2014¹). This was equivalent to 1 in every 8 deaths globally, making air pollution Air pollution is a significant problem in cities the most important environmental health risk across the world. It affects human health and worldwide (WHO 2014a). Other diseases affected well-being, ecosystem health, crops, climate, by air pollution include cardiovascular disease, visibility and human-made materials. Health immune disorders, various cancers, and disorders effects related to air pollution include its of the eye, ear, nose and throat such as cataract and impact on the pulmonary, cardiac, vascular and sinusitis. Epidemiological evidence suggests that neurological systems (Section 2). Trees affect air prenatal exposure to certain forms of air pollution quality through a number of means (Section 3) can harm the child, affecting birth outcomes and and can be used to improve air quality (Section infant mortality. Childhood exposure to some 4). However, air pollution also affects tree health pollutants also appears to increase the risk of and plant diversity (Section 5). Bioindicators can developing health problems in later life, affecting be useful for monitoring air quality and indicating the development of lung function and increasing environmental health (Section 6). Understanding the risk for development of chronic obstructive the impacts of vegetation biodiversity on air pulmonary disease (COPD) and asthma. quality and air quality on vegetation biodiversity is essential to sustaining healthy and diverse Several respiratory illnesses caused or otherwise ecosystems, and for improving air quality and affected by air pollution are on the rise. These consequently human health and well-being. include bronchial asthma, which affects between 100 and 150 million people worldwide, with $LUSROOXWLRQDQGLWVHƨHFWVRQ another 65 million affected by some form of human health COPD. Other human health problems from air pollution include: aggravation of respiratory and Air pollution can significantly affect human and cardiovascular disease, decreased lung function, ecosystem health (US EPA 2010). Recent research increased frequency and severity of respiratory indicates that global deaths directly or indirectly symptoms (e.g. difficulty in breathing and attributable to outdoor air pollution reached 7 coughing, increased susceptibility to respiratory
¹ World Health Organization, 2015. Health and the Environment: Addressing the health impact of air pollution. Sixty-eighth World Health Assembly, Agenda item 14.6. A68/A/CONF./2 Rev.1 26 May 2015. http://apps.who.int/gb/ebwha/pdf_files/ WHA68/A68_ACONF2Rev1-en.pdf (last accessed June 2015)
Connecting Global Priorities: Biodiversity and Human Health 63 infections), effects on the nervous system (e.g. pollution also affects the earth’s climate by either impacts on learning, memory and behaviour), absorbing or reflecting energy, which can lead to cancer and premature death (e.g. Pope et al. climate warming or cooling, respectively. 2002). People with pre-existing conditions (e.g. heart disease, asthma, emphysema), diabetes, and Indoor air pollution is primarily associated with older adults and children are at greater risk for particulates from combustion of solid fuel (wood, air pollution-related health effects. In the United coal, turf, dung, crop waste, etc.) and oil for heating States (US), approximately 130 000 particulate and cooking, and gases from all fuels (including
matter (PM)2.5-related deaths and 4700 ozone natural gas) in buildings with inadequate
(O3)-related deaths in 2005 were attributed to air ventilation or smoke removal. The World Health pollution (Fann et al. 2012). Organization (WHO) reports that over 4 million people die prematurely from illness attributable to Air pollution comes from numerous sources. household air pollution from cooking with solid Major causes of gaseous and particulate outdoor fuels. More than 50% of premature deaths among air pollution with a direct impact on public health children under 5 years of age are due to pneumonia include the combustion of fossil fuels associated caused by particulate matter (soot) inhaled from with transport, heating and electricity generation, household air pollution. It is estimated that and industrial processes such as smelting, 3.8 million premature deaths annually from concrete manufacture and oil refining. Other noncommunicable diseases (including stroke, important sources include ecosystem degradation ischaemic heart disease, lung cancer and COPD) (including deforestation and wetland drainage) are attributable to exposure to household air and desertification. pollution (WHO 2014b).
Plants provide an important ecosystem service Some pollutants, both gaseous and particulate, are through the regulation of air quality. Although directly emitted into the atmosphere and include
the effects of plants on air quality are generally sulfur dioxide (SO2), nitrogen oxides (NOx), positive, they can also to some degree be negative carbon monoxide (CO), particulate matter (PM) (as discussed in section 3 below). Likewise, air and volatile organic compounds (VOC). Other quality can have both positive and negative pollutants are not directly emitted; rather, they are impacts on plant populations. These various formed through chemical reactions. For example,
impacts are partially dependent upon the diversity ground-level O3 is often formed when emissions
of the plant species, vegetation assemblages and of NOx and VOCs react in the presence of sunlight. size classes. This chapter explores the role of Some particles are also formed from other directly biodiversity in regulating air quality in positive emitted pollutants. and negative terms, including a discussion of current knowledge gaps and recommendations. 3. Impacts of vegetation on air Air pollution also affects the environment. Ozone quality and other pollutants can damage plants and trees, There are three main ways in which plants affect and pollution can lead to acid rain. Acid rain can local air pollution levels: via effects on local harm vegetation by damaging tree leaves and microclimate and energy use, removal of air stressing trees through changing the chemical pollution, and emission of chemicals. Each of and physical composition of the soil. Particles these are described below. in the atmosphere can also reduce visibility. The typical visual range in the eastern US parks is (ƨHFWVRISODQWVRQORFDO 15–25 miles, approximately one third of what it would be without human-induced air pollution. microclimate and energy use In western USA, the visual range has decreased Increased air temperature can lead to increased from 140 miles to 35–90 miles (US EPA 2014). Air energy demand (and related emissions) in the
64 Connecting Global Priorities: Biodiversity and Human Health summer (e.g. to cool buildings), increased air winter-time heating energy demand by tending pollution and heat-related illness. Vegetation, to reduce cold air infiltration into buildings. On particularly trees, alters microclimates and the negative side, reductions in wind speed can cools the air through evaporation from tree reduce the dispersion of pollutants, which will transpiration, blocking winds and shading various tend to increase local pollutant concentrations. In surfaces. Local environmental influences on air addition, with lower wind speeds, the height of the temperature include the amount of tree cover, atmosphere within which the pollution mixes can amount of impervious surfaces in the area, time be reduced. This reduction in the “mixing height” of day, thermal stability, antecedent moisture tends to increase pollutant concentrations, as the condition and topography (Heisler et al. 2007). same amount of pollution is now mixed within a Vegetated areas can cool the surroundings by smaller volume of air. several degrees Celsius, with higher tree and shrub cover resulting in cooler air temperatures (Chang 2) Removal of air pollutants et al. 2007). Trees can also have a significant impact on wind speed, with measured reductions Trees remove gaseous air pollution primarily by in wind speed in high-canopy residential areas uptake through the leaves, though some gases (77% tree cover) of the order of 65–75% (Heisler are removed by the plant surface. For O3, SO2 1990). and NO2, most of the pollution is removed via leaf stomata.³ Healthy trees in cities can remove 2Temperature reduction and changes in wind significant amounts of air pollution. The amount speed in urban areas can have significant effects of pollution removed is directly related to the on air pollution. Lower air temperatures can lead amount of air pollution in the atmosphere (if to lower emission of pollutants, as pollutant there is no air pollution, the trees will remove no emissions are often related to air temperatures air pollution). Areas with a high proportion of (e.g. evaporation of VOCs). In addition, reduced vegetation cover will remove more pollution and urban air temperatures and shading of buildings have the potential to effect greater reductions in can reduce the amount of energy used to cool air pollution concentrations in and around these buildings in the summer time, as buildings are areas. However, pollution concentration can be cooler and air conditioning is used less. However, increased under certain conditions (see Section 4). shading of buildings in winter can lead to increased Pollution removal rates by vegetation differ among building energy use (e.g. Heisler 1986).² In addition regions according to the amount of vegetative to temperature effects, trees affect wind speed and cover and leaf area, the amount of air pollution, mixing of pollutants in the atmosphere, which in length of in-leaf season, precipitation and other turn affect local pollutant concentrations. These meteorological variables. changes in wind speed can lead to both positive and negative effects related to air pollution. On There are numerous studies that link air quality the positive side, reduced wind speed due to to the effects on human health. With relation shelter from trees and forests will tend to reduce to trees, most studies have investigated the
² This altered energy use consequently leads to altered pollutant emissions from power plants used to produce the energy used to cool or heat buildings. Air temperatures reduced by trees can not only lead to reduced emission of air pollutants
from numerous sources (e.g. cars, power plants), but can also lead to reduced formation of O3 ,as O3 formation tends to increase with increasing air temperatures. ³ Trees also directly affect particulate matter in the atmosphere by intercepting particles, emitting particles (e.g. pollen) and resuspending particles captured on the plant surface. Some particles can be absorbed into the tree, though most intercepted particles are retained on the plant surface. Many of the particles that are intercepted are eventually resuspended back to the atmosphere, washed off by rain, or dropped to the ground with leaf and twig fall. During dry periods, particles are constantly intercepted and resuspended, in part, dependent upon wind speed. During precipitation, particles can be washed off and either dissolved or transferred to the soil. Consequently, vegetation is only a temporary retention site for many atmospheric particles, though the removal of gaseous pollutants is more permanent as the gases are often absorbed and transformed within the leaf interior.
Connecting Global Priorities: Biodiversity and Human Health 65 magnitude of the effect of trees on pollution averages around 0.51% for particulate matter,
removal or concentrations, while only a limited 0.45% for O3, 0.44% for SO2, 0.33% for NO2, and number of studies have looked at the estimated 0.002% for CO. However, in areas with 100% health effects of pollution removal by trees. In tree cover (i.e. contiguous forest stands), air the United Kingdom, woodlands are estimated pollution improvement is on an average around to save between 5 and 7 deaths, and between 4 four times higher than city averages, with short- and 6 hospital admissions per year due to reduced term improvements in air quality (1 hour) as
pollution by SO2 and particulate matter less high as 16% for O3 and SO2, 13% for particulate
than 10 microns (PM10) (Powe and Willis 2004). matter, 8% for NO2, and 0.05% for CO (Nowak et Modelling for London estimates that 25% tree al. 2006).
cover removes 90.4 metric tons of PM10 pollution per year, which equates to a reduction of 2 deaths 3) Emission of chemicals and 2 hospital stays per year (Tiwary et al. 2009). Nowak et al. (2013) reported that the total amount Vegetation, including trees, can emit various chemicals that can contribute to air pollution. of particulate matter less than 2.5 microns (PM2.5) removed annually by trees in 10 US cities in 2010 Because some vegetation, particularly urban varied from 4.7 t in Syracuse to 64.5 t in Atlanta. vegetation, often requires relatively large inputs Estimates of the annual monetary value of human of energy for maintenance activities, the resulting emissions need to be considered. The use and health effects associated with PM2.5 removal in these same cities (e.g. changes in mortality, combustion of fossil fuels to power this equipment hospital admissions, respiratory symptoms) leads to the emission of chemicals such as VOCs, ranged from $1.1 million in Syracuse to $60.1 CO, NO2 and SO2, and particulate matter (US EPA million in New York City. Mortality avoided was 1991). typically around 1 person per year per city, but was Plants also emit VOCs (e.g. isoprene, as high as 7.6 people per year in New York City. monoterpenes) (Geron et al. 1994; Guenther 2002; Trees and forests in the conterminous US Nowak et al. 2002; Lerdau and Slobodkin 2002). removed 22.4 million t of air pollution in 2010 These compounds are natural chemicals that make (range: 11.1–31.0 million t), with human health up essential oils, resins and other plant products, effects valued at US$ 8.5 billion (range: $2.2– and may be useful in attracting pollinators or 15.6 billion). Most of the pollution removal repelling predators. Complete oxidation of VOCs occurred in rural areas, while most of the health ultimately produces carbon dioxide (CO2), but impacts and values were within urban areas. CO is an intermediate compound in this process. Health impacts included the avoidance of more Oxidation of VOCs is an important component than 850 incidences of human mortality. Other of the global CO budget (Tingey et al. 1991); CO substantial health benefits included the reduction also can be released from chlorophyll degradation of more than 670 000 incidences of acute (Smith 1990). VOCs emitted by trees can also respiratory symptoms (range: 221 000–1 035 contribute to the formation of O3. Because VOC 000), 430 000 incidences of asthma exacerbation emissions are temperature dependent and trees (range: 198 000–688 000) and 200 000 days of generally lower air temperatures, increased tree school loss (range: 78 000–266 000) (Nowak et cover can lower overall VOC emissions and, al. 2014). consequently, O3 levels in urban areas (e.g. Cardelino and Chameides 1990). Ozone inside Though the amount of air pollution removed by leaves can also be reduced due to the reactivity trees may be substantial, the per cent air quality with biogenic compounds (Calfapietra et al. 2009). improvement in an area will depend upon on the amount of vegetation and meteorological Trees generally are not considered as a source conditions. Air quality improvement by trees of atmospheric NOx, though plants, particularly in cities during daytime of the in-leaf season agricultural crops, are known to emit ammonia.
66 Connecting Global Priorities: Biodiversity and Human Health Emissions occur primarily under conditions of automobiles), and altered O3 chemistry such that excess nitrogen (e.g. after fertilization) and during concentrations of O3 increased. Another model the reproductive growth phase (Schjoerring 1991). simulation of California’s South Coast Air Basin
They can also make minor contributions to SO2 suggests that the air quality impacts of increased concentration by emitting sulfur compounds such urban tree cover may be locally positive or negative as hydrogen sulfide (H2S) and SO2 (Garsed 1985; with respect to O3. However, the net basinwide
Rennenberg 1991). H2S, the predominant sulfur effect of increased urban vegetation is a decrease compound emitted, is oxidized in the atmosphere in O3 concentrations if the additional trees are low to SO2. Higher rates of sulfur emission from plants VOC emitters (Taha 1996). are observed in the presence of excess atmospheric or soil sulfur. However, sulfur compounds also Modelling the effects of increased urban tree cover can be emitted with a moderate sulfur supply on O3 concentrations from Washington, DC to (Rennenberg 1991). In urban areas, trees can central Massachusetts revealed that urban trees additionally contribute to particle concentrations generally reduce O3 concentrations in cities, but by releasing pollen and emitting volatile organic tend to slightly increase average O3 concentrations and sulfur compounds that serve as precursors regionally (Nowak et al. 2000). Modelling of the to particle formation. From a health perspective, New York City metropolitan area also revealed pollen particles can lead to allergic reactions (e.g. that increasing tree cover by 10% within urban Cariñanosa et al. 2014). areas reduced maximum O3 levels by about 4 ppb, which was about 37% of the amount needed for attainment (Luley and Bond 2002). 2YHUDOOHƨHFWRIYHJHWDWLRQRQDLU pollution There are many factors that determine the 4. The role of plant biodiversity in ultimate effect of vegetation on pollution. Many regulating air quality plant effects are positive in terms of reducing The impacts of vegetation on air quality depend pollution concentrations. For example, trees can in part on species and other aspects of plant reduce temperatures and thereby reduce emissions biodiversity. Plant biodiversity in an area is from various sources, and they can directly remove influenced by a mix of natural and anthropogenic pollution from the air. However, the alteration of factors that interact to produce the vegetation wind patterns and speeds can affect pollution structure. Natural influences include native concentrations in both positive and negative vegetation types and abundance, natural biotic ways. In addition, plant compound emissions interactions (e.g. seed dispersers, pollinators, plant and emissions from vegetation maintenance can consumers), climate factors (e.g. temperature, contribute to air pollution. Various studies on O3, precipitation), topographic moisture regimes, and a chemical that is not directly emitted but rather soil types. Superimposed on these natural systems formed through chemical reactions, have helped in varying degrees is an anthropogenic system to illustrate the cumulative and interactive effects that includes people, buildings, roads, energy use of trees. and management decisions. The management decisions made by multiple disciplines within an One model simulation illustrated that a 20% loss in urban system can both directly (e.g. tree planting, forest cover in the Atlanta area due to urbanization removal, species introduction, mowing, paving, led to a 14% increase in O3 concentrations for a watering, use of herbicides and fertilizers) and day (Cardelino and Chameides 1990). Although indirectly (e.g. policies and funding related to there were fewer trees to emit VOCs, an increase vegetation and development) affect vegetation in Atlanta’s air temperatures due to the increased structure and biodiversity. In addition, the urban heat island, which occurred concomitantly anthropogenic system alters the environment (e.g. with tree loss, increased VOC emissions from changes in air temperature and solar radiation, the remaining trees and other sources (e.g.
Connecting Global Priorities: Biodiversity and Human Health 67 air pollution, soil compaction) and can induce In urban areas, land use, population density, changes in vegetation structure (Nowak 2010). management intensity, human preferences and socioeconomic factors can affect the amount of Much is generally known about plant distribution tree cover and plant diversity (Nowak et al. 1996; globally, but less is known about factors that affect Hope et al. 2003; Kunzig et al. 2005). These factors the distribution of plant diversity and human are often interrelated and create a mosaic of tree influences on plant biodiversity (Kreft and Jetz cover and species across the city landscape. Land 2007). Variations in urban tree cover across use is a dominant factor affecting tree cover regions and within cities give an indication of the (Table 1). However, land use can also affect species types of factors that can affect urban tree structure composition, as non-managed lands (e.g. vacant) and consequently biodiversity, with resulting tend to be dominated by natural regeneration of impacts on human health. One of the dominant native and exotic species. Within areas of managed factors affecting tree cover in cities is the natural land use, the species composition tends to be characteristics of the surrounding region. For dictated by a combination of human preferences example, in forested areas of the US, urban tree for certain species (tree planting) and how much cover averages 34%. Cities within grassland areas land is allowed to naturally regenerate (Nowak average 18% tree cover, while cities in desert 2010). regions average only 9% tree cover (Nowak et al. 2001). Cities in areas conducive to tree growth Tree diversity, represented by the common naturally tend to have more tree cover, as non- biodiversity metrics of species richness (number of managed spaces tend to naturally regenerate species) and the Shannon–Wiener diversity index with trees. In forested areas, tree cover is often (Barbour et al. 1980), varies among and within specifically excluded by design or management cities and through time. Based on field sampling activities (e.g. impervious surfaces, mowing). In of various cities in North America (Nowak et al. the US, while the per cent tree cover nationally 2008; Nowak 2010), species richness varied from in urban (35.0%) and rural areas (34.1%) are 37 species in Calgary, Alberta, Canada, to 109 comparable, urbanization tends to decrease overall species in Oakville, Ontario, Canada (Figure 1). tree cover in naturally forested areas, but increase Species diversity varied from 1.6 in Calgary to tree cover in grassland and desert regions (Nowak 3.8 in Washington, DC (Figure 2). The species and Greenfield 2012). richness in all cities is greater than the average species richness in eastern US forests by county (26.3) (Iverson and Prasad 2001). Species diversity
7DEOH0HDQSHUFHQWWUHHFRYHUDQGVWDQGDUGHUURU 6( IRU86FLWLHVZLWKGLƨHUHQW potential natural vegetation types (forest, grassland, desert) by land use (from Nowak et al. 1996)
Forest Grassland Desert Land use Mean SE Mean SE Mean SE Park 47.6 5.9 27.4 2.1 11.3 3.5 Vacant/wildland 44.5 7.4 11.0 2.5 0.8 1.9 Residential 31.4 2.4 18.7 1.5 17.2 3.5 Institutional 19.9 1.9 9.1 1.2 6.7 2.0 Other 7.7 1.2 7.1 1.9 3.0 1.3 Commercial/industrial 7.2 1.0 4.8 0.6 7.6 1.8