Michigan’s air quality declined dangerously earlier this month due to wildfire smoke from Minnesota and Canada. 

Pollutants in the smoke can have long-term health consequences for humans, pets, and wildlife. However, for trees themselves the health effects are less consequential.  

Wayne State University forestry professor Dan Kashian says that while our tree canopy is important for converting carbon dioxide into life-supporting oxygen, days or even weeks of heavy smoke plumes is unlikely to harm Michigan’s trees. He says the main effect would be on the amount of sunlight on smokey days. 

Kashian says,  “Trees need to photosynthesize…anything that affects the amount of light that they’re receiving is going to affect how well they can grow.”

According to Kashian, harmful pollutants from wildfire smoke can settle on leaves but are often washed away by rain without lasting harm to the tree’s health.  

“But when you’re talking about a couple of days of heavy smoke like this, especially when it’s hot, it can actually help them because they don’t really like really high temperatures either,” Kashian says.

This story is a part of WDET’s ongoing series, the Detroit Tree Canopy Project.

The wildfire smoke that covered Michigan skies is costing the state money. According to an Analysis from an East Lansing based Anderson Economic Group, the smoke cost the state’s economy $4 billion in losses. We are second only to the state of New York which estimated a $5 billion loss. 

The firm said that Michigan had the largest impact based on the size of its economy. Proximity could be the reason why.  

How did this happen? Well, industries that rely on outdoor work like transportation and construction contributed to these losses greatly.  Outdoor events and attractions closed as well which also points to a decrease in tourism and fewer customers at businesses that depend on the outdoors.  

The Michigan Department of Natural Resources had to tell campers with reservations that they should cancel. They also waived cancellation fees and issued refunds.   

But the losses may be ending soon as it appears the smoky haze has lifted.

As of Wednesday, the Air Now’s Air Quality index showed the air quality was between 0-50 which means the air in Michigan is in a good range. At one point last week, Michigan was rated the most polluted air quality in the world with Detroit’s air quality index at 724—for reference, anything over 301 is hazardous. 

According to the Michigan Department of Environment Great Lakes and Energy as the weather system moves about the improvements are expected to continue.  

To stay up to date on air quality, you can check EGLE’s MiAir Quality Index Dashboard or use the US Air Quality Index called Air Now.  

Additional headlines for Wednesday, July 22, 2026

Global company joins Detroit’s downtown

A company from Japan is planting their roots in Detroit. The company Nagase America opened their Mobility Solutions office in downtown Detroit.

 According to the publicly traded company, they will provide innovative materials and components that enhance vehicle comfort, performance, and efficiency.  

In a YouTube Short video, Mayor Sheffield describes how this move will expand Detroit’s global reach.

“Today sends a powerful message that a global company with nearly 190 years worth of experience had many choices where they could go and grow and expand. You could’ve expanded anywhere but you chose our talent our downtown and our future. It speaks volume of the confidence you have in our city. Your decision brings you closer to more customers, partners and innovators while strengthen Detroit’s position as a global mobility hub.”

The company says it plans to use Detroit as a long-term strategic foundation for its North American mobility operations. 

Detroit’s 325th birthday

And the 3-1-3 is turning 3-2-5. July 24^th marks the city’s 325^th anniversary.

You might be thinking, how is that possible? America just turned 250 years old! Well, it was originally founded French explorer Antoine de la Mothe Cadillac in 1701. Detroit transitioned from French to British control in 1760, and later became part of the United States following the American Revolution. 

The Detroit Historical Society is celebrating the milestone in conjunction with anniversaries for the Detroit Historical Museum and Dossin Great Lakes Museum.  

The Detroit Historical Society will host a daylong community block party on Friday, July 24 with free admission to the museum. And the Dossin takes the baton and continues the fun on Saturday, July 25, a maritime-themed “dock” party that will also include family activities, music, ice cream, food trucks and free museum admission.

Listen to the latest episode of the “Detroit Evening Report” on Apple Podcasts, Spotify, NPR.org or wherever you get your podcasts.

Smoke from wildfires in Ontario and Minnesota has been lingering in Michigan skies. 

Some of it started on July 7, when lightning struck the woods of northern Minnesota. Those fires burned so hard the Forest Service shut the Boundary Waters completely. And the fires went both directions. One crossed into Canada, another crossed out of it, into Minnesota.

Meanwhile, four Republicans in Michigan’s delegation wrote to Canada’s prime minister last week, demanding Canada manage its forests better. They say they are done “accepting apologies in place of action.” This comes as the U.S. Forest Service, the agency that manages federal forests and firefighting on this side of the border, faces significant budget cuts under the Trump administration’s latest proposals.

Bobbie Scopa fought fire for 45 years. She started as a seasonal firefighter in 1974 and finished as an operations section chief: the person on a major fire who decides where the crews go, and where nobody goes at all. She’s the author of “Both Sides of the Fire Line,” and she hosts the podcast Bobbie on Fire. 

She joined Robyn Vincent on The Metro to explain why these fires are harder to stop than they used to be, and why she thinks Americans are asking the wrong question about them.

Hear the full conversation using the media player above.

Listen to The Metro weekdays from 10 a.m. to noon ET on 101.9 FM and streaming on-demand. Never miss an episode — subscribe to The Metro on Apple Podcasts, Spotify, YouTube, or NPR, or wherever you get your podcasts. Have thoughts? Email the show at metro@wdet.org.

More from The Metro

Wildfire smoke at times last week made Detroit’s air quality the worst in the world — that’s in a place that consistently gets terrible grades for heavy pollution.

So, how is our health impacted by poor air quality?

Dr. Garen Wolff is an allergy and immunology physician at the Detroit Medical Center. She says people with asthma are having to use inhalers too often.  

“It should be (used) less than twice a week, but when we have poor air quality for long periods of time, I have patients using their rescue inhaler every day and that’s not healthy for the lungs to do,” says Wolff.

Dr. Wolff spoke with The Metro’s Robyn Vincent about the health consequences of breathing smoke-filled air.  

Listen to The Metro weekdays from 10 a.m. to noon ET on 101.9 FM and streaming on-demand. Never miss an episode — subscribe to The Metro on Apple Podcasts, Spotify, YouTube, or NPR, or wherever you get your podcasts. Have thoughts? Email the show at metro@wdet.org.

More from The Metro