University Of Tasmania
107651 final.pdf (780.59 kB)

Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools?

Download (780.59 kB)
journal contribution
posted on 2023-05-18, 18:06 authored by MacNeill, M, Dobbin, N, St-Jean, M, Wallace, L, Marro, L, Shin, T, You, H, Kulka, R, Allen, RW, Amanda WheelerAmanda Wheeler
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.


Publication title

Indoor Air: International Journal of Indoor Air Quality and Climate










Menzies Institute for Medical Research


Blackwell Munksgaard

Place of publication


Rights statement

Copyright 2015 Her Majesty the Queen in Right of Canada. Licensed under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Repository Status

  • Open

Socio-economic Objectives

Public health (excl. specific population health) not elsewhere classified

Usage metrics

    University Of Tasmania