The quality of our air directly impacts our health and the natural environment, so we want our air to be as clean as possible. Unfortunately, contaminants from a variety of sources are released into the atmosphere every day and affect the quality of our air.
The Ministry of the Environment works to protect and improve air quality through legislation, targeted programs, and partnerships with other jurisdictions.
Air pollution in Ontario comes from a range of sources, including:
- mobile sources (cars, trucks, and buses; recreational vehicles; lawn and gardening equipment; farming and construction; rail and marine)
- stationary sources (factories, power plants and residences)
- open sources (paved and unpaved roads, construction, agriculture)
- natural sources (forest fires and emissions from trees and other vegetation)
These and other sources release a variety of contaminants into the air, including:
- pollutants that cause smog and acidic rain
- toxic and hazardous substances
- greenhouse gases that contribute to global warming
It's important to note that not all of the contaminants that pollute Ontario's air are actually created here. Many pollutants reach our province from hundreds, or even thousands of kilometres away. These border-crossing pollutants, commonly referred to as "transboundary air pollution," contribute significantly to Ontario's air quality issues.
For comprehensive information about Ontario's air quality, see the ministry's annual Air Quality in Ontario Reports.