Environment Canada has issued a special air quality statement for parts of Ontario, including Sarnia and Lambton County, London and Middlesex County, Windsor and Essex County, Chatham-Kent, Oxford County, Elgin County, Huron County, Perth County, Bruce County, and Grey County.
The agency said there was a possibility of deteriorating air quality Friday.
Hot and sunny conditions are expected to cause increasing ground-level ozone concentrations Friday afternoon, creating high levels of air pollution.
Environment Canada said individuals may experience symptoms such as increased coughing, throat irritation, headaches or shortness of breath. Children, seniors, and those with cardiovascular or lung disease, such as asthma, are especially at risk.
If you are experiencing symptoms, consider reducing or rescheduling strenuous outdoor activities until the special air quality statement is lifted.
UPDATE: The special air quality statement ended just before 10 p.m. on Friday.