Benefits from investing in high indoor air quality
Pawel Wargocki ([email protected]) International Centre for Indoor Environment and Energy Technical University of Denmark – DTU Civil Engineering www.ie.dtu.dk “great care is devoted to ensuring that we have a pure water supply and noone would suggest that in the interest of economy we should be doomed to drink polluted water; on aesthetics ground alone it should be one’s right to be allowed to live and work in a clean atmosphere which is free from objectionable odours”
Bedford (1964) The Right to Healthy Indoor Air (WHO, 2000) P1. Under the principle of the human right to health, everyone has the right to breathe healthy indoor air. P2. Under the principle of respect for autonomy (self-determination), everyone has the right to adequate information about potentially harmful exposures, and to be provided with effective means for controlling at least part of their indoor exposures. P3. Under the principle of non-maleficence (doing no harm), no agent at a concentration that exposes any occupant to an unnecessary health risk should be introduced into indoor air. P4. Under the principle of beneficence (doing good), all individuals, groups and organisations associated with a building, whether private, public or governmental, bear responsibility to advocate or work for acceptable air quality for the occupants. P5. Under the principle of social justice, the socio-economic status of occupants should have no bearing on their access to healthy indoor air, but health status may determine special needs for some groups. P6. Under the principle of accountability, all relevant organisations should establish explicit criteria for evaluating and assessing building air quality and its impacts on the health of the population and on the environment. P7. Under the precautionary principle, where there is a risk of harmful indoor air exposure, the presence of uncertainty shall not be used as a reason for postponing cost-effective measures to prevent such exposure. P8. Under the ‘‘polluter-pays’’ principle, the polluter is accountable for any harm to health and for welfare resulting from unhealthy indoor air exposures. In addition, the polluter is responsible for mitigation and remediation. P9. Under the principle of sustainability, health and environmental concerns cannot be separated, and the provision of healthy indoor air should not compromise global or local ecological integrity, or the rights of future generations. Indoor air is significant contributor to life- time exposures Sources of Indoor Air Pollutants
• Outdoor air: combustion, industrial pollution, traffic, pollens, etc. • Building: building materials, furnishing, equipment, consumer products, etc. • Ventilation system: ventilation, air-conditioning • Humans: occupants & their activities 2,000,000 Healthy Life Years are Lost every year due to Exposure Indoors in EU
Cleaning and other household Building materials Ventilation and conditioning Furnishing, interior materials and electric appliances Ambient air quality Building site (radon from soil)
Heating and combustion
Water systems, dampness and mould
ETS excluded! Source: EnVIE Project (2009) DALY = Disability Adjusted Life Years • One DALY can be thought of as one lost year of "healthy" life • The sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost due to Disability (YLD) for incident cases of the health condition • The YLL is the number of deaths multiplied by the standard life expectancy at the age at which death occurs • YLD is the number of incident cases multiplied by the average duration of the disease and a weight factor that reflects the severity of the disease on a scale from 0 (perfect health) to 1 (dead) DALY = YLL + YLD 2,000,000 Healthy Life Years are Lost every year due to Exposure Indoors in EU
Cleaning and other household Building materials Ventilation and conditioning Furnishing, interior materials and electric appliances Ambient air quality Building site (radon from soil)
Heating and combustion
Water systems, dampness and mould
ETS excluded! Source: EnVIE Project (2009) Burden of disease by disease from compromised IAQ in Europe: DISEASES (HEALTH)
[kDALY] Acute CO toxication Respiratory infectious 104 48 diseases Asthma
661
Sick building syndrome, sensory irritation 517
Lung (& trachea & bronchus) cancer 125
64 674 COPD Cardiovascular diseases ETS excluded! Few environmental factors are responsible for most of the environmental burden of disease in Europe
Lead Ozone Dioxins Benzene Radon Formaldehyde
Noise
SHS PM2.5
Source: IAIAQ Project (2011); an update to EnVie Project (2009) 400 to 1,100 DALYs per 100,000 inhabitants in the US (residential buildings, ETS included)
PM2.5 Acrolein Formaldehyde
Source: Logue et al., EHP (2012) Ambient PM2.5 levels in Europe in 2005
Source: ETC/ACC Technical Paper (2008) WHO air quality guidelines
Selected indoor chemicals establish targets at which health risks are significantly reduced
• Carbon monoxide • Nitrogen dioxide • Benzene • Formaldehyde • Naphthalene • Trichloroethylene • Tetrachloroethylene • Polycyclic aromatic hydrocarbons (PAHs) • Radon Multitude exposures indoors
Do we know what we don’t know?
• There could be contaminants of concern that are as yet unidentified, but that have significant health effects “New chemicals and other contaminants appear in buildings almost daily. Many in the indoor air community fear that some of these may be significant health hazards either singly or in combination. Undoubtedly some will. But rather than speculate on that it makes more sense to work with the information we have on contaminants that have demonstrated harm to the population, like particles, formaldehyde and products of combustion.
Sherman M. ASHRAE Journal February (2013) Major IEQ (IAQ) concerns in the western world • Many report building related- symptoms when working in offices
• IEQ in schools is appalling
• Prevalence of asthma and allergy is growing rapidly Studies in offices in Europe/Asia/USA
• 20-40% of occupants with building-related symptoms • 10-60% of occupants finding the IAQ unacceptable
• Even though the existing ventilation standards are met Building-related symptoms
• Irritation of mucous membranes, eyes, nose, skin and respiratory tract • Difficulty to concentrate • Headache • Fatigue
Some evidence on SBS and methods to control exposures Improving indoor environmental quality can increase office productivity by 5-15%
• Studies in Europe, Japan, Singapore and USA 1.06 • Experimental studies in laboratories with human 1.04 subjects • Studies in existing office 1.02 buildings with employees • Conclusion: Indoor 1.00 environment does affect productivity 0 20 40 60 80 • Quantitave relationships have been developed Dissatisfied (%) between IEQ and productivity
Improving indoor environmental quality can increase office productivity by 5-15%
• Studies in Europe, Japan, Singapore and USA • Experimental studies in laboratories with human subjects • Studies in existing office buildings with employees • Conclusion: Indoor environment does affect productivity • Quantitave relationships have been developed between IEQ and productivity
Thermal discomfort and
performance of office work
Reduction in performance Thermal sensation vote
Source: Lan et al. (2011) Sick-leave
% sick leave 2.5
2
1.5
1 35% lower
0.5
0 12 24 Outdoor air supply rate (L/s per person) Workspace satisfaction as a function of indoor environmental parameters and building features
• All parameters statistically significant (p<0.05) • The most important parameters: satisfaction with amount of space, noise level and visual privacy • Satisfaction with amount of space the most important regardless occupants’ gender and age, type of office (single office, shared office, cubicles) and distance from a window
Self-estimated job performance as a function of satisfaction with indoor environmental parameters and building features
• The most important parameters: satisfaction with temperature, noise level and air quality • One-unit (~15%) increase in satisfaction with temperature would increase self-estimated job performance by about 1%
Estimated annual savings from changes in building factors in U.S. (1997 data)
• Infectious diseases: $6-$19 billion • Allergies and asthma: $1-$4 billion • Acute sick-building (SBS) health problems: $10-$20 billion • Direct impact of indoor environment on worker performance (unrelated to health): $12-$125 billion Total: $30-$170 billion/year Total:
~$20
billion per year LCC analyses, example
• 12,300 m2 office building with 864 p; • air quality from 50% to 10% dissatisfied; • The annual benefit of increased productivity due to improved air quality >> the increase in annual energy and maintenance costs • Estimated pay-back time < 2 year • Profit: 4-7 times higher than with interest rate at 3.2% Productivity gain of just 10% would offset the full running and installation costs
Although there is some level of uncertainty to which extent IEQ affects productivity even improvements <1% are COST-EFFECTIVE
The effects are sufficiently high to promote investments in high indoor environmental quality Source: Wargocki and Seppänen (2006); Building Value, Energy Design Guidelines for State Buildings Office of the State Architect, California (1976) Schools
• 20% af EU’s population, 30% of time in schools • Children are more vulnerable; their bodies are still growing • Children must attend school; they can not absent themselves or find another school • The work that children are obliged to perform in schools is not optional and almost always new • Conditions are much worse than in offices (higher occupancy, less ventilation)
Education system has changed, the buildings did not the systems are not accommodating new needs
2000 Schools 1500
1000 Offices 500
CO2 concentration (ppm) concentration CO2 0 0 10 20 30 Ventilation rate (L/s/person) CO2 measurements in Scandinavian schools
More than half of 742 classrooms investigated were inadequately ventilated (Denmark)
Ventilation principles
100% n=15 90% n=16 n=27 80% n=380 70% n=23 Natural 60% 50% Exhaust n=195 40% n=132 Balanced 30% n=84 20% n=223 10% 0% Denmark Sweden Norway Temperature and performance of school work
% 120
110
100 8%
90 skole øvelserskole
Performance 80 Præstation af rutinemæssige af Præstation
70
18 20 22 24 26 oC TemperatureTemperatur Ventilation and performance of school work
% 110
105
9% 6% 100
95
skole øvelserskole Performance
90
Præstation af rutinemæssige af Præstation
85 0 2 4 6 8 10 L/s/person VentilationUdelufttilførsel rate National standard educational tests and ventilation
p<0.008
4
2 1.3 0.6 0 -0.2
-2 Adjusted national test result (%) result test national Adjusted
-4 IndblæsningMechanical og Kun udsugningExhaust (n=31) NaturligNatural ventilation (airing by udsugningbalanced (n=81) windows)(n=146) Consequences
• 15% reduced performance = 1 school year • Costs are unknown (more time for leisure or learning) (renovation costs perhaps less than 50 eurocents/day/pupil) • Can be approximated by absenteeism for pupils (parents) and teachers or by the cost of teacher (5% less time gives ca. 40-50 eurocents saving) • May be approximated by the loss of opportunity (salary) as regards future work • May have future consequences for national economy
Renovations Energy costs Renovation costs Payback time Rentability (assuming 5% less time used by teachers, in extra salary for teachers) “It is certain that the additional expenses per pupil of the best ventilation needed not exceed the price of one or two cheap lunches.”
New Hampshire School District Ventilation Code, 1893 STAR Project, USA, 20 years later Improving air quality in Danish schools
CO2 measurements in Scandinavian schools
Source: Report on Mass Experiment (2009) CASE: Increase of ventilation rate from 6 L/sp (according to Danish Building Code) to 8.4 L/sp (Swedish requirements) Estimated effect on PISA Changing ventilation rate from 6 to 8.4 L/sp will improve performance by 6% which corresponds to ca. 0.1 standard deviation from the mean : ca. 0.1 std. dev. corresponds to ca. 10 PISA points
10 PISA points (0.1 std. dev.) corresponds to 4% less taking 10th grade ; finally assumed (conservative estimation) that 2% will complete earlier the education effect on sick absence of teachers
1.0
0.8 days - 0.6
0.4
0.2
Reduction in sick in Reduction 0 0 1 2 3 4 Air change rate (1/h) Source: Seppänen et al. (2006) CASE: Changing ventilation rate from 6 to 8.4 L/sp will reduce sick leave by 4% which corresponds to ca. 0.5 day a year or 0.2% of working year Performance in schools, effect for public budget and GDP
Average annual effect Trend of effect
Public budget: TOTAL €37 million Rising
• increased productivity €16 million Rising
• fewer pupils in 10th class €15 million Rising
• lower teacher sick leave €6 million Constant
GDP total €170 million Rising
• increased productivity €104million. Rising
• fewer pupils in 10th class €67 million Rising
• lower teacher sick leave N/A N/A
DANISH GDP (2011): €240,000 million Homes
• Low ventilation rates • Many materials containing plasticizers Prevalence of asthma symptoms (wheezing) and ventilation
Europe Wheezing VentilationVentilation Finland
Sweden Estonia Russia Latvia
Ireland
United Kingdom Poland Germany
Austria France Romania
Italy Portugal Spain Albania
Greece Risk (odds ratio) of symptoms of asthma and allergy (wheezing, rhinitis, eczema) as a function of ventilationRelative rates risk inof allergicsingle family symptoms houses 3
2
1
0 0.17 0.26 0.38 0.62 h-1 -1 MedianAir change air change rates in (hhomes) Prevalence of house dust mites in homes Prevalence (number of homes) 20 (P=0.024) 15 >100mites per 0.1g mattress dust
10
5
0 =0.25 0.25- 0.50 >0.50 Air Airchange change rates rate (h (h-1-1) ) Plasticizers in homes and the risk (odds ratio) of asthma Dampness, lack of moisture removal Risk (odds ratio) of bronchial obstruction
<0.5 h-1 12 >0.5 h-1
8 Odds ratio Odds 4
0 Dampness Textile wall Plasticizer paper Exposure What a new-born should do not to become allergic (Sundell, 2007) • be a girl (up to 10 years of age), with a non-smoking, non- allergic, ginger-loving breast-feeding mother, not speaking english • choose a non-allergic father not speaking english • avoid pets (cats and dogs) if there are allergies in the family • choose to live on a farm with animals in a communist country • stay at home, avoid day care or school • have at least some worm infections at an early age • stay away from soft plastics, waterbased paints and many cleaning products = not stay indoors The primary purpose of office/school/dwelling is to provide an optimal conditions for work/learning/leisure and not only to conserve energy How can energy be conserved w/o affecting IEQ?
30.6 GTCO2 in 2010 (5% increase) max. 32 GTCO2 aimed in 2020 EPBD 2002
The Directive 2002/91/EC Energy performance of buildings – a measure to improve the energy performance of buildings Directive requires that the improvement of energy performance of buildings would be met with respect to indoor climate requirements, so the energy reduction can have no negative effect on indoor environment conditions
Building cerification schemes
Provide a framework to design and build green buildings as well as to assess sustainable building performance. Is voluntary, though considered prestigious. Have been on the construction market for the last 15 years and are not anymore a niche segment.
LEED Section Possible Points Sustainable sites 26 Points Water efficiency 10 Points Energy and atmosphere 35 Points Materials and resources 14 Points Indoor environmental Quality 15 Points Total 100 Points Innovation in Design 6 Points Regional priority 4 Points
Satisfaction and LEED certification
Altomonte and Schaivon, Building and Environment, 2013 Problems in low-energy buildings
Strategic priorities to control exposures (EnVie, 2009)
• Policies re. energy efficiency, building materials, products and maintenance • Policies re. the impact of outdoor environment • Policies re. specific building construction and equipment • Developing health-based ventilation guidelines to control exposure to pollutants
Impact of ventilation on indoor expsoures
Fisk et al. REHVA J, 2011 Avoid sources! HealthVent Project, Decision Diagram for Defining Health-Based Ventilation Rates
• Outdoor air is an important source of exposures occurring indoors. • Indoor air quality must comply with WHO guidelines being the scientific ‘state of the art’ leading to the criteria to manage air quality indoors as well as outdoors. • Source control is the priority strategy in controlling exposures. • Ventilation regulations are based on and justified by health criteria. • The base ventilation rate is defined to be 4 L/s per person and is related to human bioeffluents. • Health-based ventilation rate in a specific buildings can not be lower than the base rate. • Health-based ventilation is decoupled from ventilation for controlling thermal comfort. • Ventilation systems must support health-based ventilation. • The health-based ventilation rates ensure that exposures meet the WHO air quality guidelines after the source control has been implemented. • Health-based ventilation rates can not be lower than the base rate of 4 L/s per person applicable when (Health-related) Base X timesX times Reference Base Ventilation Rate (4 L/s.p) human bioeffluents are the only source of air Ventilation Rate pollution. Natural or mechanical ventilation?
•Natural ventilation does not always guarantee lower temperatures or increased outdoor air supply rate but can perform as good as mechanical ventilation under certain conditions •Opening of windows can increase noise and pollution (e.g. from traffic) •Hybrid systems may be a way to go Potential retrofit solution
- In classrooms pupils are one of the major source of pollution
- Metabolic CO2 can be used as an indicator of whether ventilation is adequate
- The retrofit solution providing continuous feedback to teachers and pupils on CO2 levels in classrooms
- The windows in classrooms are
opened/closed based on CO2 levels using green-yellow-red indication
- Simple retrofit solution easy to install
Source: Exhausto, DK
Results, heating season, windows opening and CO2
(w/o cooling)
Results, cooling season, windows opening and CO2 Air cleaning technologies are of increasing importance, especially when building ventilation rates are being reduced to save energy and the sources of indoor air pollutants can not be completely controlled. Effects of air cleaning on indoor expsoures • Filtration is an efficient technology for removing particles, although used particle filters can be a source of sensory pollution. • Sorption is an efficient technology for removing some gaseous pollutants. More data is needed on its long term performance. • UVGI is a proven technology for inactivation of some airborne microorganisms such as bacteria, fungi and viruses, but ozone may be produced during operation. • By-products of PCO and plasma need to be identified and controlled before these techniques are applied widely. • Ozone is not recommended for indoor air cleaning. • Benchmarks and standard condition and procedures for evaluating air cleaner performance are needed.
Zhang et al., Atmosperic Environment 2011 Regulation of IEQ (IAQ)
Outdoor AQ AMBIENT AIR GUIDELINES Certification schemes (DGNB-DK) and/or building codes
Ca. 35 standards in Europe; rates defined by comfort
VENTILATION & INFILTRATION Other guideline values, e.g. INDEX.
HUMAN HEALTH SOURCES EXPOSURES UPTAKE (COMFORT)
LABELLING SCHEMES Indoor AQ Classes of GUIDELINES comfort (% CONSUMER PROD . dissatisfied) Buildings do not use energy, people do! Energy use in 290 identical houses Human behaviour, impact on temperature in 23 dwellings Adaptive systems with optimum control “in many respects today we submit ourselves to dramatic sudden changes in climate several times a day withouth giving it a second’s thought” (Proctor, 1982) Questions? Thank you