Wildfires in Ontario make Toronto air quality worst in world

Environment Canada issued health warnings after sky over city turns yellow Smoke from more than 100 active wildfires in northern Ontario have made Toronto’s air quality the worst in the world on Wednesday and caused yellow, smoky air in cities across the northeast US. Environment Canada issued health warnings on Wednesday after the sky over country’s largest city turned a sickly yellow and was ranked the worst in the world according to IQAir, the Swiss technology company that racks global air qu