The latest report on the environment from Ontario's Auditor General's office points out the province's air quality is getting better, but there's still work to do, particularly in Windsor-Essex, Chatham-Kent, and Sarnia-Lambton.
The State of the Environment in Ontario report, which looks at water pollution, air pollution, waste, and wildlife, was released on Tuesday.
It said fossil fuels continue to be the leading cause of poor air quality, but since 1990, levels of sulphur dioxide fell by 90 per cent, and 60 per cent for carbon monoxide and volatile organic compounds. Nitrogen oxide levels are down 26 per cent since 2009, and nitrogen dioxide fell 21 per cent.
Despite the improved air quality, exposure to fine particulate matter, nitrogen dioxide, and ozone contributed to 6,580 premature deaths in 2016, about seven per cent of total deaths in Ontario that year. Data in the report from Health Canada also blamed poor air for 3,350 visits to emergency rooms and 910 hospital admissions.
Windsor-Essex, Chatham-Kent, and Sarnia-Lambton had the most special air quality statements between 2015 and 2021. Just five regions had smog or air health advisories during that period, and three were in Southwestern Ontario.
(Graphic courtesy of the Office of the Auditor General of Ontario)
The annual provincial average for ground-level ozone, fine particulate matter, and nitrogen oxide between 2015 and 2017 was 40.7 parts per billion. Essex County topped that with 47.7 parts per billion, the worst in Ontario.
It was also the worst for summer ozone at 57.1 parts per billion, while Chatham-Kent was second with 53.7. Ontario's average for summer ozone was 44.4.
The province has 39 air monitoring stations across Ontario and has been collecting data for five decades.
It credits improved overall air quality to the decision to phase out coal-fired power plants between 2005 and 2014 and better technology to control emissions.