ENVIRONMENTAL LAW INSTITUTE Indoor Air Quality in Homes State Policies for Improving Health Now and Addressing Future Risks in a Changing Climate December 2016 ACKNOWLEDGMENTS The Environmental Law Institute gratefully acknowledges the assistance of many individuals who provided information about the policy initiatives discussed in this report and reviewed draft materials. Funding for this report was provided by the U.S. Environmental Protection Agency. The contents of the report are the responsibility of ELI. The views expressed herein should not be attributed to EPA, nor should any official endorsement be inferred. About ELI Publications ELI publishes Research Reports that present the analysis and conclusions of the policy studies ELI undertakes to improve environmental law and policy. 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Cover Photo: Verena Matthew/Shutterstock.com TABLE OF CONTENTS CHAPTER 1: Introduction .................................................................................................... 1 CHAPTER 2: Wildfire Smoke ................................................................................................ 8 CHAPTER 3: Dampness and Mold ...................................................................................... 28 Licensing of Mold Service Providers................................................................ 33 Establishing Minimum Standards for Rental Housing ...................................... 46 CHAPTER 4: IAQ and Home Energy Efficiency Retrofits ..................................................... 60 CHAPTER 5: Conclusion ..................................................................................................... 84 Introduction CHAPTER 1 Introduction Communities throughout the United States are experiencing a variety of conditions associated with a changing climate – hotter summers and heat waves, droughts, intense storms and flooding, increased average precipitation and humidity, and more severe wildfires. Alongside potentially far-reaching environmental and economic impacts, these conditions have direct and indirect effects on human health. Many of the health effects are associated with exposures that occur where people spend the vast majority of their time – indoors. Indoor air quality (IAQ) is affected by complex interactions among indoor and outdoor environmental conditions and pollution sources, building features, and human activities. Pollutants found indoors can be of both indoor and outdoor origin. Pollutants can be generated indoors by sources and activities such as cooking, smoking, cleaning, fuel-burning combustion appliances, and chemicals emitted from building materials, furnishings, and household and personal care products. Pollutants that are found outdoors can also move inside buildings. Air can enter and leave a building through natural ventilation (windows and doors), infiltration (other openings or cracks in the building envelope), and mechanical ventilation systems. Outdoor conditions such as air pollution, humidity, and precipitation influence the indoor environment, depending on factors such as the building envelope, mechanical ventilation systems, and occupant behaviors.1 Studies by the U.S. Environmental Protection Agency (EPA) indicate that indoor levels of pollutants may be two to five times higher than outdoor levels, and occasionally as much as 100 times higher.2 Over the past few decades public health science research has enhanced greatly our understanding of the health and productivity effects associated with indoor biological and chemical contaminants and with building conditions such as dampness and poor ventilation.3 These health effects include upper and lower respiratory disease and symptoms, headaches, skin problems, fatigue, neurological impairment, 1 See generally U.S. EPA, An Introduction to Indoor Air Quality, https://www.epa.gov/indoor-air-quality-iaq/introduction- indoor-air-quality. 2 U.S. EPA, IAQ Tools for Schools Action Kit: IAQ Backgrounder at 1, http://www.epa.gov/iaq/schools/actionkit.html; U.S. EPA. Why Indoor Air Quality is Important to Schools, https://www.epa.gov/iaq-schools/why-indoor-air-quality-important-schools. 3 See generally Calif. Air Resources Board, Health Effects of Indoor Pollutants (2013), http://www.arb.ca.gov/research/indoor/healtheffects1table1.htm; Lawrence Berkeley National Laboratory (LBNL), IAQ Scientific Findings Resource Bank: Human Performance, http://iaqscience.lbl.gov/performance-summary; U.S. EPA, Indoor Air Quality, http://www2.epa.gov/indoor-air-quality-iaq. 1 Indoor Air Quality in Homes developmental disorders, and cancer.4 Children are particularly vulnerable to the health effects of indoor pollutants, since their bodies are still developing and they have relatively higher rates of breathing and metabolism.5 Many indoor pollutants that can cause or trigger asthma may have especially harmful effects on the nearly seven million children and 18 million adults in the U.S. who suffer from asthma.6 The growing body of public health science research demonstrates that IAQ issues are already a significant problem in the United States: “By one estimate, poor indoor conditions cost the nation’s economy tens of billions of dollars a year in exacerbation of illnesses and allergenic symptoms and in lost productivity.”7 Over the past several years scientists have begun to examine and describe comprehensively how indoor environmental quality may be affected by a changing climate. Recent government and academic reports have illuminated a broad range of potential impacts on indoor air quality. This report discusses three of these residential IAQ issues: wildfire smoke; dampness and mold; and the effect of energy efficiency upgrades on indoor air quality. The chapters that follow describe in detail current state policies and programs in these areas, highlighting approaches for consideration by other jurisdictions. State and local policymaking on these and other IAQ issues is important whether or not specific climate predictions come to pass. Regardless of the magnitude of climate change impacts in the future, “Poor indoor environmental quality is creating health problems today and impairs the ability of occupants to work and learn.”8 States thus have an opportunity to put in place policies that not only prepare for anticipated increased future risks, but also reap considerable health and economic benefits in the near term. Recent Scientific Reviews This report focuses on IAQ issues identified in several recent scientific reviews describing current knowledge of the anticipated effects of climate change on indoor environmental quality.9 In 2011, the Institute of Medicine at the National Academy of Sciences issued a comprehensive report summarizing the current state of scientific understanding with respect to the effects of climate change on indoor air quality. The report, Climate Change, the Indoor Environment, and Health, addresses five topic areas: indoor air pollutants; indoor dampness and mold; infectious agents, insects, and arthropods found indoors; indoor temperature and humidity; and building weatherization, ventilation, and energy 4 See generally Calif. Air Resources Board, Indoor Air Pollution in California: Executive Summary at 1-9 (2005), http://www.arb.ca.gov/research/indoor/ab1173/ab1173.htm; U.S. EPA, America’s Children and the Environment (3rd ed.) (2013), http://www.epa.gov/ace/. 5 U.S. EPA, America’s Children and the Environment, supra, at 8. 6 Centers for Disease Control and Prevention (CDC), Fast Stats: Asthma, http://www.cdc.gov/nchs/fastats/asthma.htm. 7 National Academy of Sciences – Institute of Medicine, Climate Change, the Indoor Environment, and Health at 3 (2011), https://www.nap.edu/catalog/13115/climate-change-the-indoor-environment-and-health. See also LBNL, IAQ Scientific Findings Resource Bank: Human Performance, http://iaqscience.lbl.gov/performance-summary. 8 Institute of Medicine, Climate Change, the Indoor Environment, and Health, supra, at 7. 9 In this report, footnotes citing these and other publications exclude internal references in the cited publications. 2 Introduction use.10 The report concludes generally that, while there has been little research to determine the associations between climate change-induced alterations in the indoor environment and specific adverse health outcomes, “the available