DULUTH – Canadian wildfires filling Minnesota skies with smoke show no sign of easing, and Minnesota health officials are warning that hazardous air will continue blanketing the entire state into next week.

The Minnesota Pollution Control Agency is extending an air quality alert that was to end Friday afternoon until 3 p.m. Tuesday for the entire state. The worst of it will arrive on Saturday morning, with a "very unhealthy" air forecast for the Twin Cities metro area stretching in a broad area north to the Canadian border. The rest of the state is also under alerts of "unhealthy" or "unhealthy for sensitive groups."

Health officials said those with heart and lung conditions should limit their exposure outdoors, and everyone who can avoid exertion — indoors or outdoors — should do so. Heavy smoke that carries fine particulate matter can increase the chances of heart attack.

"It inevitably means there's going to be more heart attacks — usually emergency heart attacks," said Dr. Rory Farnan, an interventional cardiologist at Essentia Health in Fargo. "We tend to see it on bad air days in cities all over the world."

The smoke is streaming into Minnesota from uncontrolled fires on more than half a million acres in Ontario, and some of the largest are in remote areas about 150 miles north of Lake of the Woods.

"If you're experiencing smoke, you're probably getting it from the large fires on the Ontario/Manitoba border," said Chris Marchand, fire information officer for the Ontario natural resources ministry.

A cluster of smaller fires are burning on thousands of acres in Quetico Provincial Park, some just a mile from the Minnesota border. "In the larger scheme of things, we have larger fish to fry in terms of our larger regional situation," Marchand said. The Quetico fires are being observed but not actively battled, he said.

Already Ontario has had nearly twice as many fires this year — 976 — compared with its 10-year average. The same drought conditions that are plaguing Minnesota and the American West set the stage for an intense fire season in Canada this summer.

Biden calls fire summit

President Joe Biden convened a virtual meeting Friday with governors of several states where wildfires are an urgent issue and told Minnesota Gov. Tim Walz that he has been in contact with Canadian Prime Minister Justin Trudeau and mentioned "worrying about this from both sides of the border."

"We are coordinating as best we can," Biden said.

Between 20 and 30 new fires have been reported every day this week in Ontario, including a small lightning-caused fire in Quetico that sparked Thursday, Marchand said. There are a total of 151 active wildfires in northwest Ontario.

"We've been getting rain but it's not enough to address the underlying drought conditions," Marchand said. "If we can have a couple of days without new starts we can address the fires a lot better."

Firefighters from Connecticut and other states have poured into Minnesota to battle fires and keep an eye on the blazes in Quetico Provincial Park. While those fires are smaller, they have prompted closures in the Boundary Waters Canoe Area Wilderness and threaten to reach across the border near Iron and Crooked lakes and torch parts of the state's cherished wilderness.

Crews have already had a busy season battling blazes inside Superior National Forest, and there were nine active fires in the forest on Friday. The largest is the Fourtown Lake fire burning on 220 acres about 12 miles northeast of Ely, said Sarah Shapiro, a public information officer for the U.S. Forest Service.

Multiple out-of-state teams have assisted firefighting in Minnesota this season as "resources are spread thin across the state," Shapiro said. She estimates that they have about 93 firefighters on the ground across Superior National Forest. Some of these firefighters are from Michigan, Pennsylvania, Connecticut and New Hampshire.

For the fires burning in the state caused by lightning, Shapiro said there has been no recent growth, though fire danger remains high and plenty of work is still ahead.

"Mop-up operations take a long time," she said. "They need to feel with their hands for heat and put out any heat they find and repeat that process over and over."

Fire restrictions remain in place throughout the forest, and a number of areas have been closed.

From floods to droughts

Walz told Biden "our children couldn't be outside" as he spoke about Minnesota seeing some of the worst air quality readings the state has ever seen just the day before.

"Wildfires are causing the worst air quality on record in Minnesota, just as we're heading into our warmest and driest month," Walz said in a statement after the meeting. "Climate change is real, it's having a direct impact on Minnesotans' lives, and it requires all of us to work together."

Biden told the group that "wildfires are a problem for all of us, and we have to stay closely coordinated in doing everything we can for our people." Walz also focused attention on Minnesota's worsening drought situation. Governors from Wyoming, Montana, Idaho, Oregon, Washington and California joined him for the Friday event.

"Large portions of my state that are in drought, unprecedented drought, two years ago were in unprecedented flooding situations," Walz said during the meeting. "So these massive swings are going to continue on, and collaboration, communication and I think creative thinking like we're hearing here from a lot of these governors is going to be needed."

Staff writer Alex Chhith contributed to this report.

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