Toronto the orange: Wildfire smoke leaves city under dirty sky with no relief likely until Friday

Environment Canada placed Toronto under an orange-level air quality warning Wednesday due to wildfire smoke from northwestern Ontario. That means a dirty sky is hanging over the city, blotting out distant landmarks. Some residents have taken to wearing masks to keep out fine particles in the smoke.

Toronto the orange: Wildfire smoke leaves city under dirty sky with no relief likely until Friday A look at the city blanketed by smoke from fires burning in northwestern Ontario Environment Canada has placed Toronto under an orange-level air quality warning due to smoke from wildfires burning in northwestern Ontario. That means a dirty sky, with an orange tinge, is hanging over the city, blotting out distant landmarks. Some residents have taken to wearing masks to keep out the fine particles in the smoke.

The federal weather agency says in the warning that conditions may improve Friday morning. The Ontario government says there were 148 active wildland fires in the province's northwest region as of Tuesday evening. Of these fires, 69 are not under control, seven are being held, five are under control 67 are being observed.

The province says 26 new wildland fires were discovered in the region. Environment Canada says residents may experience eye, nose and throat irritation, headaches, chest pains or severe cough. Seniors, pregnant people, young children, people with an existing health condition and people who work outdoors are more likely to be affected by smoke.

"Limit time outdoors. Reschedule or cancel outdoor sports, activities and events," Environment Canada says in the warning. Toronto Public Health has activated its wildfire smoke response strategy due to the smoky air in the city.

That means the public health unit is promoting the use of cleaner air spaces for residents who face barriers accessing cleaner air and air filtration at home, according to Toronto Mayor Olivia Chow. Six locations are available: Metro Hall, Toronto City Hall, and the North York, Scarborough, York and East York Civic Centres. The air quality warning was issued Tuesday night, before a heat event in the city ended.

Environment Canada lifted a yellow-level heat warning for the city shortly before 4 p.m. Wednesday. Toronto ranked first in a list of the world's most polluted major cities as of Wednesday morning, according to a global ranking by IQAir, a Swiss air quality technology company. It has since dropped to second place behind Kinshasa in the Democratic Republic of Congo.

Environment Canada meteorologist Brian Owsiak said the smoke will likely "flush" out with the shift in wind direction coming later in the week or during the weekend. With files from Muriel Draaisma