what is good iaq?
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RESPIRATORY HEALTH & ENVIRONMENT SUMMIT
For Life and Breath: Allergies, Asthma, and the Environment
Panel
"Clearing Airways: Creating Asthma and Allergy Friendly Homes, Schools and Workplaces"
John Molot MD CCFP FCFP
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What is good IAQ?
1. No contaminants at concentrations likely to be harmful
2. No conditions that are likely to be associated with occupant health or comfort complaints stuffy air, poor temperature control, dampness
3. Virtually no occupants express dissatisfaction
Indoor Air Quality Guide. ASHRAE 2009
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Canadians spend 90% of time indoors
Do we really have good IAQ?
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Would you live here?
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Would you live here?
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Highway 401
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5000 people aged 55-69 living near a major road followed for 8 years had double the risk for death from cardiopulmonary causes
Lancet 2002 Oct 19;360(9341):1203-9
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Proximity to Major Road(50-500 m)
AllergiesAsthmaRespiratory infectionsOthers
Boothe VL. J Environ health. 2008 Apr;70(8):33-41
Major road = 10,000 vehicles/24 hrToronto:• Highway 401 (Weston Rd and Hwy 400) = 442,900 • Yonge St. = 51,000• Sheppard (Bayview and Yonge) = 30,000
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Major Outdoor Pollutants
*** Particulate matter (<PM2.5)*** Ozone (O3)Nitrous oxides (NOx)Sulfur oxides (SOx)Carbon monoxideVolatile organic compounds (VOCs)
Influence could be additive or synergistic
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IAQ 4 – 7x worse than outdoor air
Indoor VOCs and SVOCs are higher• 30 - 100 in typical building• over 900 VOCs and SVOCs have been identified indoors• there are few health-based guidelines for VOC concentrations in
non-industrial indoor environments• no guidelines for SVOCs• no guidelines for combinations
SVOCs are much higher indoors (e.g. PBDE, PFOS) PM is lower, but different components. • outdoor air and indoor sources both contribute• SVOCs and other contaminants adsorb, especially to UFP
Ozone is reduced 30-70% but increases when outside levels are higher
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VentilationPresent ventilation standards and guidelines: modest requirement that the indoor air shall be acceptable to 80% of occupants. not based on health effects
Current building codes, standards and guidelines: based primarily on practical experience within the building sector based on non-health related criteria such as perceived acceptability of air does not consider other contaminants.
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Things we know can go wrong …
CORadon
1 in 15 homes 10 % lung cancer
Water intrusion decays materials increases growth and activity of biologicals
o insectso mouldso bacteria
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Indoor PM (dust) contents• human hair • animal fur• human skin cells • animal skin cells (dander)• animal secretions
o urine• insect particles• insect excretions • bacteria
o endotoxins• food particles
• mould o sporeso hyphaeo cell components o mycotoxinso mVOCs
• fibers of textiles, paper• insulation particles• minerals from outdoor soil• others e.g. hobbies, paint • adsorbed SVOCs and VOCs
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Moisture Increased mite activity Increased mite feces production Increased mould growth (humidity > 60%)
spores hyphae (biomass) cell components - enolase, beta-glucans mycotoxins mVOCs
Increased bacteria growth endotoxins
Decay of organic building materials VOCs
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Moisture and Health Risk The evidence for a causal association
between dampness and respiratory health effects is strong
wheeze asthma recurrent airways infections nasal congestion rhinitis hoarse voice
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Indoor air soup:Add contents constantly and stir continuously
Contents: PM, VOCs, SVOCs, other chemicals, O3, biologicals
Stir continuously:
Chemical reactions:
1. Mixture in air2. Production of PM3. Adsorption4. Oxidation5. Surface chemistry*
*surfaces enhance effective reaction rates
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“Chemical cocktail”or
Indoor chemistry Indoor pollutants react with each other. occurs either in the gas phase or on surfaces large surface area compared to outdoors walls, floors, carpets, furnishings skin and respiratory tract (breathing zone)
oxygenation (ozone) reactions, acid-base reactions, hydrolysis reactions, and decomposition reactions
major source of free radicals and other short-lived reactive species in indoor environments
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Poor ventilation is associated with asthma in kids• Carreiro-Martins P. Eur J Pediatr. 2014 Mar 4. (ahead of print)
Exposures to volatilized components of water-based paint, water-based cleaning products, glass cleaning, oven cleaning, dish-washing, and the use of chlorine bleach significantly increases the risks of acute asthma, and other acute respiratory symptoms.
• Choi H. Int J Environ Res Public Health. 2010 Dec;7(12):4213-37.
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ASHRAE Standards and Guidelines• do not consider interactions• do not consider susceptible groups
Who is susceptible?
Children – increased exposures relative to adults– organ systems are still maturing– immature detoxification systems
Women– More allergies and asthma– Poorer detoxifiers
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Abnormal Genotype for Detoxification (poor detoxifiers)
• more susceptible to the respiratory effects of air pollution
• poor detoxification can adversely affect lung function, including increasing the risk of ozone-induced asthma and wheezing
• Poor detoxification leads to oxidative stress
Islam T. Glutathione-S-transferase (GST) P1, GSTM1, exercise, ozone and asthma incidence in school children. Thorax. 2009; 64(3):197-202.
Romieu I. GSTM1 and GSTP1 and respiratory health in asthmatic children exposed to ozone. Eur Respir J. 2006 Nov;28(5):953-9.
McCunney RJ. Asthma, genes, and air pollution. J Occup Environ Med. 2005; 47(12):1285-91
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Oxidative stress can damage cells
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Oxidative stress• Chronic asthma is associated with oxidative stress• Oxidative stress is increased in acute exacerbationsFatani SH. Biomarkers of oxidative stress in acute and chronic bronchial asthma. J
Asthma. 2014 Mar 19. (ahead of print)
• Oxidative stress can be caused by indoor exposures:Mould Hope J. ScientificWorldJournal. 2013 Apr 18;2013:767482.
VOCs Kim JH. Ind Health 2011;49(1):8-14
SVOCs • Phthalates: Kovacic P. Med Hypotheses 2010 Apr;74(4):626-8
• PBDE: Fernie KJ. Toxicol Sci 2005 Dec;88(2):375-83
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ASHRAE Position Document on Indoor Air Quality July 21, 2011
• providing superior IAQ can: – improve health, work performance and school
performance – reduce health care costs
Treatment“superior air quality”
Improvement of IAQ by a factor of 2–7 compared with existing standards:
decreases risk of allergic symptoms decreases risk of asthma increases office productivity Increases school learning
Something is wrong with present standards 26
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Treatment • Improve ventilation• Decrease contamination sources• Clean (filter) the air
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Reduce exposures
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Take a deep breath
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