Thick smoke from the hundreds of wildfires scorching western Canada has blanketed the city of Vancouver, sounding alarm over dangerous air quality levels on par with cities in China or India, Agence France-Presse reports.

“It’s very, very hazy outside,” Vancouver air quality official Francis Ries told AFP. “We used to see the mountains (on the city’s north shore), but now we can’t see them at all.”

According to officials, the smoke drifted in more than a week ago from the 563 fires across the western province of British Columbia. It is expected to last several more days, triggering the longest air quality alert in the seaport’s history.

Some of the smoke is also coming from wildfires scorching northern California.

The smoke has brought hazardous levels of fine particulate matter, higher than those in Beijing and more than double the amount of what’s safe for health, AFP reports.

Poor air quality can be especially dangerous for infants, the elderly, and people with diabetes, or lung or heart disease.

All summer the U.S. and Canada have been battling massive wildfires, exacerbated by hot and dry weather. This month, two wildfires in Northern California grew to be the largest in the state’s history.

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