Hazy holiday: Air quality drops as wildfire smoke blankets southwestern Ontario

Environment Canada has issued special air quality statements for southwestern Ontario as Prairie wildfire smoke sits over swaths of the province.

People in the Windsor, Chatham, and Sarnia regions can expect poor air quality and reduced visibility, Environment Canada said Monday morning. "The wildfire smoke may persist into tonight and possibly Tuesday before finally easing." 

But on Monday afternoon, Environment Canada updated the statements to say the smoke could stick around until Wednesday.

Detroit and Toronto were among the top ten most polluted major cities in the world on Monday, according to a ranking by Swiss company IQAir.

The CBC News Climate Dashboard also showed Windsor and other southwestern Ontario cities had some of the worst air quality in the country on Monday.

Environment Canada warned of potential health effects, including "mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough." Wheezing, chest pains, or severe cough are less common but more serious symptoms. 

Older people, young kids, people with chronic conditions, pregnant people, and those who work outside are at higher risk, Environment Canada said. "If you think you are having a medical emergency, seek immediate medical assistance."

The federal weather authority also urged people to limit time outside and consider rescheduling outdoor activities, adding that windows and doors should be kept closed as much as possible.

"If you must spend time outdoors, a well-constructed, well-fitting and properly worn respirator type mask (such as a NIOSH-certified N95 or equivalent respirator) can reduce your exposure to the fine particles in the smoke," Environment Canada said.