Smoke from wildfires in Canada and the American West is starting to affect air quality in Michigan.
The smoke carries tiny particles of ash and soot called PM 2.5 -- flecks of particulate matter that are less than 2.5 microns in diameter, or about one-thirtieth the width of a human hair.
Stephanie Hengesbach, a meteorologist with the state’s air quality division, said those particles are especially dangerous for people with heart or lung problems.
“Be aware of it,” she advised. “Levels are higher than typical this time of year. When you breathe, it can become trapped into your lungs. That’s why it’s so important that people that have lung or breathing issues really be aware.”
Hengesbach said so far, levels of pollutants have stayed in the “moderate” range of the Environmental Protection Agency’s air quality index, but even that can be uncomfortable for people with sensitive lungs.
Those people should avoid strenuous exercise and stay indoors as much as possible while the sky is hazy, she said.
The weather patterns that carry smoke to Michigan are tough to predict, Hengesbach explained.
“Warm air rises. These smoke plumes are typically warm, so they’re going to rise up into the atmosphere, and they can get caught up in the upper level windflow. That’s why they can travel such far distances,” she said.
“Depending on the wind speed at upper levels, and if systems are coming through, sometimes those winds from upper levels can get pulled down to the surface.”
Hugh McDiarmid, a spokesperson for the state Department of Environment, Great Lakes and Energy, said most of the smoke over Michigan has been staying in the upper atmosphere.
“We had a couple one-hour spikes in certain areas of the state,” he said, “but it is not affecting air quality on a consistent basis, at least not yet.”
The smoke is visible on satellite imagery and in other forecasting software the air quality division is using to track it, said Hengesbach.
She’s expecting the plume to drift north over the Upper Peninsula and into Canada on Friday, but a new weather front could bring it back over the Lower Peninsula this weekend.
“It’s something that we’re honestly paying attention to daily,” Hengesbach said.
