Busy wildfire season exposing millions in the US to dangerous smoke

Heavy smoke from several large wildfires blazing in Canada and Minnesota is expected to engulf large swaths of the Midwest and Northeast U.S. this week, exposing millions of people to dangerous air pollution.

Over 100 wildfires currently are burning in Canada and winds are carrying the smoke southeast. Warnings about dangerous, unhealthy air extended Wednesday from Minnesota through Toronto and into New York. Unusually hot summer temperatures were expected too.

Related: Doctors warn of health risks as wildfire smoke drifts across Utah

The best advice is to stay indoors to avoid both the smoke and the extreme heat, said Tyler Hasenstein, meteorologist with the National Weather Service in Chanhassen, Minnesota.

“Those two things coinciding with each other is not good from a health perspective,” he said.

Rangers try to get thousands of campers out of remote Minnesota wilderness

In far northeast Minnesota, rangers were trying to warn people that the Boundary Waters Canoe Area Wilderness was closed because about 17 fires caused by lightning were burning around the vast wilderness accessible primarily by canoe.

The area was closed Tuesday and rangers estimated anywhere from 6,000 to 10,000 people were still inside the 1.1-million-acre (445,000-hectare) wilderness, which is almost the size of Delaware, Superior National Forest spokesperson Joy VanDrie said.

“It’s an arduous job,” VanDrie said of rangers and campers having to canoe for hours or even carry their boats over land to evacuate.

VanDrie didn’t know when the area might reopen. Minnesota officials said some fires in the Boundary Waters will be allowed to burn indefinitely but will be monitored to ensure they don’t threaten people or property.

Even the Canadian Air Force pitched in. They were rescuing two groups of youth campers Wednesday who had crossed the border and appeared to be safe, Minnesota Gov. Tim Walz said.

Severe drought and heat have led to a busy wildfire season

Dan Westervelt, associate professor at Columbia University’s Climate School, said severe drought conditions combined with heat in Canada and the U.S. have created “a perfect storm for really dry conditions to provide a lot of fuel for these wildfires to burn.” Research shows warming temperatures from burning coal, oil and gas are making fires more frequent and intense.

High levels of fine particulate matter in the air from wildfire smoke may be unhealthy for sensitive groups, such as children and people with heart or lung conditions. The particulates can cause shortness of breath, coughing, dizziness or fatigue and aggravate heart and lung diseases and other chronic health issues.

Experts suggest wearing a N95 mask if you have to be outside and keeping your indoor air cleaner by closing windows and running an air purifier or air conditioner.

It’s been a particularly busy and deadly fire season in the U.S. About four dozen large fires are currently burning across 15 states, from Minnesota and North Carolina to Colorado, Utah, Idaho, Oregon and California, according to the National Interagency Fire Center.

Prolonged drought and record-low snowpack levels combined to make conditions ripe for rapid fire growth. More than 16,800 people are assigned to fighting blazes across the county. The fires have burned over 5,678 square miles (9,138 square kilometers) — more than the size of Yellowstone and Grand Canyon national parks combined, the agency said.

Smoke spreads as officials warn wildfires could burn for months

In Minnesota, officials warned large fires could burn for months. In Minneapolis, the high Wednesday was expected to be 96 degrees F (36 C) and temperatures above 90 F (32 C) were expected the rest of the week.

“It could well be we’re having significant fires throughout the summer until we have snow. Snow would be a good thing,” said Patty Thielen, director of the state Department of Natural Resources.

Officials in Michigan and Wisconsin warned residents about air quality issues that could last for days and the problems extended even to Maine, where residents were reporting a yellowish and brownish color in the sky.

The most intense smoke could spread as far south as Washington, D.C., by midday Thursday.

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Associated Press writers Susan Montoya Bryan and Jeffrey Collins contributed to this report.

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