See more of the story

Smoky air blowing into the state from wildfires scorching Canada and the western United States is making it hard for many Minnesotans to breathe and elevating health risks for those with underlying conditions such as asthma, COPD and allergies.

But even people in good health are experiencing watery eyes, stuffy noses and coughing and sneezing brought on by several days of poor air quality, said Dr. Bryan Williams, a pulmonologist with M Health Fairview.

"It's not a lot different than breathing in secondhand smoke," he said. "You may be wondering, 'Why am I congested and why don't I feel good?' "

Lungs and eyes are among the body's most sensitive organs, Williams said, and prolonged exposure to pollution can bring on irritation and symptoms often associated with allergies, especially for children, the elderly and people who spend a lot of time outdoors.

A slight reprieve is in store for Saturday as winds shift and usher in clearer air, but smoky conditions aren't likely to disappear anytime soon, said Nick Carletta, a meteorologist with the National Weather Service in Chanhassen.

"It will be hard to be totally [smoke] free until the fires are put out," he said.

The Minnesota Pollution Control Agency (MPCA) expects Canadian wildfires to worsen through the summer, and the drought that has gripped the region shows no signs of ending. The MPCA, which issued four smoke alerts in July, is likely to issue more in the coming weeks or months, said David Brown, MPCA air quality forecaster and meteorologist.

"This wildfire smoke event was historic, probably the worst one we've experienced, and I think it probably opened a lot of people's eyes," he said.

With toxic air drifting across much of the nation, people should pay close attention when air quality alerts are issued, said Dr. Andrew Stiehm, a pulmonologist with Allina Health's United Lung and Sleep Clinic in St. Paul.

"There is a lot more stuff in the air that we are not used to inhaling," he said. Smoke puts more carbon monoxide into the air. When heat and sunlight mix with exhaust from cars and industry, ozone levels rise. Heat and humidity compound the problem.

"The air is more viscous, and it's harder to get it in and out," Stiehm said. "Add the smoke and you have more problems. This stuff can cause lungs to act up with spasms, coughing and shortness of breath."

Research published in the January issue of Proceedings of the National Academy of Sciences shows that during a large wildfire, smoke can account for 25% of dangerous air pollution in the United States. Winds pick up particles emitted from burning trees and vegetation and carry them thousands of miles. Some research suggests that breathing in environmental pollution can increase the chances of suffering a heart attack, Stiehm said.

The ongoing pollution has not sent people rushing to emergency rooms, but Stiehm said many of his patients are using their inhalers a lot more often. During air quality alerts, people should stay indoors as much as possible, he said, and watch if symptoms develop and don't abate.

"Watch to see if you cough more while exercising, or if you have cold-like symptoms that don't go away in five to seven days," Stiehm said. "That might be a sign they are being impacted. It's severity and duration."

That is when it may be time to see a doctor, he added.

For most, however, the hazy summer may just feel like an early arrival of allergy season, with itching eyes and noses and respiratory discomfort. "Smoke can bring that and the intensity can raise that quickly," said Williams, the M Health Fairview pulmonologist.

If there has been a silver lining, it's that the murky skies delivered a slight break from the sizzling weather. Temperatures were a few degrees cooler than forecast this week as the haze obscured the sun. Smoke will often stay at higher levels in the atmosphere, Carletta said, but as the temperatures shoot into the mid- and upper 90s this weekend, chances are greater the smoke will reach the surface level, creating a repeat of this week's heavy haze.

"For my patients, this was a terrible week and they could not leave the house," Williams said. "You can't take clean air for granted."

Tim Harlow • 612-673-7768