More than 212 active fires were burning in the country as of Tuesday afternoon, half of which were out of control, according to the Canadian Interagency Forest Fire Centre.
Smoke from wildfires burning in three Canadian provinces has covered about a third of the United States, forecasters said, but had little effect on air quality except in New England and parts of New York state and the Midwest.
Alerts were issued on Tuesday for parts of Canada and the neighbouring US, warning of the haze, which brought hazardous levels of particulate pollution to Minnesota, stretched from the Dakotas through the Ohio Valley, into the Northeast and as far south as Georgia, according to the National Weather Serviceโs Weather Prediction Center in College Park, Maryland. It was especially thick in New York and New England.
โMuch of the smoke is aloft in the upper atmosphere, so in a lot of areas, there arenโt air quality issues,โ said the National Weather Serviceโs Marc Chenard on Wednesday. โBut there are air quality issues as far south as New York and Connecticut, where itโs thicker and in the lower atmosphere.โ
Scores of wildfires have spread across Canada since the start of May. More than 212 active fires were burning in the country as of Tuesday afternoon, half of which were out of control, according to the Canadian Interagency Forest Fire Centre. So far, 2 million hectares (4.9 million acres) have burned. Most of the fires were in the west-central provinces of Manitoba, Saskatchewan and Alberta.
A water tanker air base was consumed by flames in Saskatchewan province, oil production has been disrupted in Alberta, and officials warned of worse to come, with more communities threatened each day.
โWe have some challenging days ahead of us,โ Saskatchewan Premier Scott Moe told a news conference, adding that the number of evacuees could rise quickly.
Yang Liu, a professor of environmental health at Emory University in Atlanta, said infants, the elderly and other frail people were most susceptible to the smoke, but emphasised that everyone is at risk. โIt will affect everyone at some level, all walks of life,โ Liu said. โItโs bad.โ
He said the smoke is comprised of small particles, some of them toxic, that are smaller than 1/40th of the width of a human hair and can get into the lungs and even dissolve into the bloodstream.
One of the worst spots for air quality in the northeastern US on Wednesday morning was Williamstown, Massachusetts, near the stateโs borders with Vermont and New York. It registered a โvery unhealthyโ reading of 228, according to IQAir, a website that monitors air quality around the world.
An air quality rating of below 50 is considered to be โgood,โ and readings between 100 and 300 are deemed โunhealthyโ to โvery unhealthy,โ while higher than that is considered โhazardous,โ according to the website.
The ratings in other parts of the US Northeast were much lower, with New York Cityโs standing at 56 on Wednesday morning and Washingtonโs registering at 55.
Air quality levels in some parts of the Midwest had also improved on Wednesday morning. Ely, near Minnesotaโs border with Manitoba, registered a โmoderateโ reading of 65, down from 336 on Tuesday. Minneapolis, which had ranked as the third-worst city in the world for air quality on Tuesday, with a 168 reading, was registering at 96.
