Smoke from forest fires over northern Ontario and the Prairies is causing a deterioration in air quality over the area. The poor air quality will gradually improve from north this afternoon to south tonight as smoke tracks south. However, smoke is expected to return to far northwestern Ontario on Sunday morning and northwestern Ontario on Sunday afternoon. ### As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events. You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough. More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance. People more likely to be impacted by outdoor air pollution, including people aged 65 and older, pregnant people, infants and young children, people with an existing illness or chronic health condition, and people who work outdoors, should reduce or reschedule strenuous activities outdoors and seek medical attention if experiencing symptoms. Visit http://www.airhealth.ca for information on how to reduce your health risk and your personal contribution to pollution levels, as well as for current and forecast AQHI values. Please continue to monitor alerts and forecasts issued by Environment Canada.