Wildfire smoke has descended on Toronto to kick off the week, and the air locals are breathing Monday morning has been ranked as the worst in the entire hemisphere.Fires burning in Quebec have blanketed Ontario with thick smoke since the weekend, and the haze of pollution has officially settled over Toronto.With an air quality index of 86 on the pollution-ranking site IQAir, Toronto ranked 19th-worst for air quality worldwide as of 8 a.m. on Monday. However, zooming in on just the Americas, Toronto's air quality ranked as the worst in the Western Hemisphere to kick off the workweek.IQAirWhile the air quality isn't as bad as Toronto has experienced during previous bouts of drifting wildfire smoke in past years, the pollution, coupled with the extreme heat event on tap this week, could combine for some hazardous conditions.Environment and Climate Change Canada warns that Toronto air quality poses a "moderate" health risk on Monday, and forecasts similar conditions ...