Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools?
Traffic emissions have been associated with a wide range of adverse health effects. Many schools are situated close to major roads, and as children spend much of their day in school, methods to reduce traffic-related air pollutant concentrations in the school environment are warranted. One promising method to reduce pollutant concentrations in schools is to alter the timing of the ventilation so that high ventilation time periods do not correspond to rush hour traffic. Health Canada, in collaboration with the Ottawa-Carleton District School Board, tested the effect of this action by collecting traffic-related air pollution data from four schools in Ottawa, Canada, during October and November 2013. A baseline and intervention period was assessed in each school. There were statistically significant (P < 0.05) reductions in concentrations of most of the pollutants measured at the two late-start (9 AM start) schools, after adjusting for outdoor concentrations and the absolute indoor-outdoor temperature difference. The intervention at the early-start (8 AM start) schools did not have significant reductions in pollutant concentrations. Based on these findings, changing the timing of the ventilation may be a cost-effective mechanism of reducing traffic-related pollutants in late-start schools located near major roads.
Air Health Science Division, Health Canada, Ottawa, ON, Canada. morgan.macneill@hc-sc.gc.ca.
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MacNeill
Air Health Science Division, Health Canada, Ottawa, ON, Canada.
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Dobbin
Air Health Science Division, Health Canada, Ottawa, ON, Canada.
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St-Jean
Santa Rosa, CA, USA.
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Wallace
Population Studies Division, Health Canada, Ottawa, ON, Canada.
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Marro
Air Health Science Division, Health Canada, Ottawa, ON, Canada.
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Shin
Air Health Science Division, Health Canada, Ottawa, ON, Canada.
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You
Air Health Science Division, Health Canada, Ottawa, ON, Canada.
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Kulka
Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
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Allen
Air Health Science Division, Health Canada, Ottawa, ON, Canada.
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Wheeler
D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D009864:Ontario; D012574:Schools; D013997:Time Factors; D001335:Vehicle Emissions / Q000032:analysis*; D014691:Ventilation / Q000379:methods*
D000393:Air Pollutants; D001335:Vehicle Emissions
HVAC system operations; Indoor air quality; Infiltration factor (Finf); Schools; Traffic-related air pollutants; Ventilation