Switching from diesel to electric school buses improves air quality for kids and communities.

Diesel exhaust is a chemically complex mixture of gases, particles and other compounds. Many of these, including nitrogen dioxide, (NO2) fine particulate matter (PM2.5), PAHs, benzene, volatile organic compounds (VOCs), and sulphur dioxide (SO2), are linked to acute and chronic health impacts. It is classified as a Level 1 carcinogen by the International Agency for Research on Cancer. According Health Canada, diesel exhaust can lead to increased risk of asthma, allergy symptom, lung cancer, heart problems, and other impacts.

Children are more sensitive to air pollution (including diesel exhaust) because of their higher breathing rates and activity levels, and developing lungs. Numerous studies have shown that prenatal and childhood exposures to traffic emissions can cause the onset or worsening of asthma, delayed lung function development, and childhood leukemia, and there is evidence suggesting links to autism spectrum disorder, delayed cognitive development, and childhood obesity. Childhood exposure can also impact health into adulthood, according to the Ontario Public Health Association. 

Exhaust from diesel school buses leads to higher pollutant levels inside buses, in school yards and inside schools (when buses are arriving, leaving or idling). and in communities where buses travel.

Studies have shown that pollutant levels can be higher inside buses than on the roadside, as exhaust is drawn into the bus itself. For example, a 2001 study in the USA showed that children on the bus were exposed to 4 times more exhaust than the people riding in cars on the road. Another study showed that particulate concentrations were higher when bus windows were closed. Other studies have found similar results.

Electric buses do not have an internal combustion engine - that means no tailpipe and no toxic fumes.

Switching to electric school buses can improve short and long term health outcomes. Reducing exposure to diesel exhaust on school buses through retrofits that reduce emissions has been shown to have measurable effects on health and cognitive function. For example, a study in Georgia, USA found that retrofitting improved students' lung function and test scores in English and Math. Electric buses would be the ultimate retrofit, and confer even greater health benefits.