Canadians face high risk' air pollution as fires spread

Hundreds of wildfires burning across Canada, many of them out of control, have blanketed cities in a thick haze of smoke, amid warnings from experts that the situation will continue to worsen.

- Leyland Cecco

Toronto has long been known as "the Big Smoke" for its history of heavy industry, but the nickname took on a different meaning yesterday when residents donned masks outside, following alerts from officials that the city's air quality would continue to deteriorate. Outdoor school events were delayed and vulnerable groups warned to remain inside if possible.

In the capital, Ottawa, Environment Canada said the air quality was "very high risk", with similar warnings for the nearby cities of Kingston, Cornwall and Belleville.

In much of southern Ontario, the poor air quality is expected to persist into the weekend.

The bulk of the smoke in eastern Canada is coming from the province of Quebec, where crews are contending with more than 150 fires, many considered "out of control".