WILDFIRE SMOKE FROM CANADA BLANKETS ONE-THIRD OF U.S.

Forecasters reported that smoke from wildfires in three Canadian provinces has spread across roughly one-third of the United States, with minimal impact on air quality except in New England, parts of New York, and the Midwest.

On Tuesday, alerts were issued for areas in Canada and the adjacent U.S., warning of haze that brought dangerous levels of particulate pollution to Minnesota. The smoke extended from the Dakotas through the Ohio Valley, reaching the Northeast and as far south as Georgia, according to the National Weather Service’s Weather Prediction Center in College Park, Maryland. The haze was particularly dense in New York and New England.

“Much of the smoke is aloft in the upper atmosphere, so in a lot of areas, there aren’t air quality issues,” said the National Weather Service’s Marc Chenard on Wednesday. “But there are air quality issues as far south as New York and Connecticut, where it’s thicker and in the lower atmosphere.”

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.

“We have some challenging days ahead of us,” 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. “It will affect everyone at some level, all walks of life,” Liu said. “It’s bad.”

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.