Electric school buses and student health
Children are regularly exposed to vehicle exhaust while waiting for and riding school buses, where emissions are most concentrated. Research links this exposure to respiratory illness, cognitive effects, and longer-term health risks—making the transition to electric school buses a meaningful public health opportunity, especially in regions with high asthma rates.
Why does air quality around school buses matter?
Children are regularly exposed to air pollution while waiting for, boarding, riding, and exiting school buses. Diesel engine exhaust (DEE) is most concentrated close to the vehicle, where children and school staff are often present.
What health effects are linked to diesel engine exhaust (DEE) in children?
Exposure to DEE can cause or worsen respiratory conditions, including asthma and other chronic lung diseases. Children with existing respiratory conditions are particularly affected.
Is asthma already a concern for students in York Region?
Yes. Public Health Ontario data show that both the incidence and prevalence of asthma among school-aged children in York Region are higher than the Ontario average and the highest of any region in the province.
Why are children more vulnerable to air pollution than adults?
According to University of Toronto occupational and environmental health scientist Stephanie Ziembicki, children breathe more air relative to their body size due to higher respiratory rates, smaller lung capacity, and higher metabolic demands. Because their lungs and bodies are still developing, inhaled pollutants can have a greater impact. Children “are not just small adults and can’t be viewed as such.”
What is diesel engine exhaust made of?
DEE is a mixture of hundreds of gases and fine particles. The International Agency for Research on Cancer (IARC) classified diesel engine exhaust as a human carcinogen in 2012. In 2025, IARC also classified automotive gasoline exhaust as a Group 1 carcinogen, with sufficient evidence linking it to bladder cancer and leukemia.
Are there short-term neurological effects from DEE exposure?
Yes. While research is still developing, evidence suggests that acute exposure to diesel engine exhaust may cause short-term central nervous system effects, including light-headedness, dizziness, vomiting, and numbness or tingling in the extremities.
Does traffic-related air pollution affect learning and mental health?
Yes. A University of British Columbia Faculty of Medicine study found that even brief exposure to traffic-related air pollution is associated with reduced cognitive performance and increased symptoms of depression.
Are there long-term health effects beyond the lungs?
Yes. Long-term exposure to traffic-related air pollution (TRAP) has been associated with cardiovascular effects. TRAP includes emissions from both diesel- and gasoline-powered vehicles, including school buses.
Are there economic and social impacts linked to these health effects?
Health conditions associated with air pollution contribute to increased school absences and higher healthcare use. These impacts are most pronounced for children with asthma, other respiratory illnesses, and mental health conditions, affecting families, schools, and healthcare systems.
Can reducing diesel exhaust exposure make a difference?
Reducing children’s exposure to diesel exhaust in school transportation can lower health risks, support attendance, and contribute to improved health, learning, and overall well-being.
Canadian School Bus Fleet (2025)
This visualization highlights how the vast majority of Canadian school buses are still diesel-powered, with electric buses representing a small but growing portion of the fleet.
Electric bus electrification snapshot
Additional resources
Research by David Hawkins on behalf of Climate Action Newmarket-Aurora. Please contact us if you have any further questions and we can set up a time to discuss.
Climate Action Newmarket-Aurora seeks to engage citizens, institutions and policymakers in actionable and measurable solutions to oppose the course of catastrophic climate change as quickly, safely and equitably as possible.
Appendix A: References
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Public Health Ontario. Asthma incidence and prevalence by Ontario health region. Most recent available regional surveillance data for school‑aged children. Public Health Ontario.
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Ziembicki, S. Occupational and Environmental Health Scientist, University of Toronto. Expert commentary on children’s vulnerability to inhaled pollutants and health effects of diesel engine exhaust.
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International Agency for Research on Cancer (IARC). (2012). Diesel and gasoline engine exhausts and some nitroarenes. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 105.
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International Agency for Research on Cancer (IARC). (2025). Automotive gasoline engine exhaust classified as Group 1 carcinogen. IARC evaluation summary.
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University of British Columbia Faculty of Medicine. Study findings on short‑term exposure to traffic‑related air pollution and associations with reduced cognitive performance and depressive symptoms.
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Traffic‑Related Air Pollution and Cardiovascular Health. Peer‑reviewed epidemiological studies demonstrating associations between long‑term exposure to traffic‑related air pollution and cardiovascular outcomes.