Air quality warnings are issued jointly by ECCC and the Ontario Ministry of Environment, Conservation and Parks (MECP) when the air quality health index (AQHI) reaches a high-risk range (AQHI 7-10) or the very high risk range (10+). These warnings can range from a few hours to a few days and include when wildfire smoke is expected to cause deteriorating air quality.
Outdoor air pollution can be harmful, especially over a long period of time. Those most at risk include people with pre-existing cardiovascular or respiratory conditions, children, and older adults (65+). When extreme heat and poor outdoor air quality occur at the same time, prioritize cooling down.
Visit the OPH Outdoor Air Pollution webpage for information on how residents can protect themselves from outdoor air pollution, including wildfire smoke, and suggestions on how to reduce exposure. Air Quality Ontario (a website of MECP) has additional health messaging.
