Overview:
- A new tool suggests Canadian wildfires in 2023 may have caused 169 deaths in Michigan, including two dozen in Detroit.
- One expert warns wildfire smoke risks are not fully understood, and some studies show it's more harmful than other particulate pollution.
- Residents and leaders are urged to take smoke threats seriously and limit exposure.
Wildfire smoke led to at least 169 deaths in Michigan last year, according to published Cornell University data. The data show a high level of mortality across the Midwest and Northeast, especially in large cities like Detroit, Chicago and New York City.
The findings give a sense of the toll the 2023 wildfires took in states where residents were unaccustomed to dealing with wildfire smoke.
Alistair T. Hayden, an assistant professor in Cornell University’s Department of Public and Ecosystem Health who worked on the mapping tool, said that more needs to be done to prepare residents for the growing threat of wildfire smoke, the dangers of which are still not fully understood.
“The location of impact is really changing rapidly,” Hayden said. “People should be prepared for wildfire smoke, even if they live very far from traditionally fire-prone areas.”
Hayden said the smoke is many times more dangerous than the flames themselves and that it can cause illness or death while the smoke wave is occurring, as opposed to cigarette smoke, which can take decades to cause health issues. Children, seniors and those with lung and other health conditions are among those most vulnerable to the impacts of wildfire smoke.
Giving an up-to-date picture of smoke risk
The mapping tool is intended to provide a very recent snapshot of the health dangers residents may be experiencing. Hayden said it can otherwise take months or years to get a sense of the impact of smoke, whereas the map makes estimates of fatalities available within 24 hours.
The map uses national and global data to determine individual risk from wildfire smoke, looking at factors like age and pre-existing conditions such as asthma. So, it wouldn’t account for the vulnerability to smoke impacts in places like Detroit, where the asthma rate is 46% higher than the state as a whole.
Still, based on population alone, the mortality estimation tool found Metro Detroit was the most heavily impacted part of Michigan in 2023, with more than two dozen fatalities.
Hayden stressed that researchers are still working to understand the risks posed by wildfire smoke, but that it appears to be deadlier than other types of fine particulate matter (PM 2.5) pollution.
Fine particulate matter, which can also come from sources like smokestacks and roads, is 30 times smaller than a human hair, allowing it to lodge itself in lung cells and move into the bloodstream. It’s associated with cardiopulmonary illnesses, premature mortality and mental health issues.
Some research has found that the PM 2.5 from wildfires is potentially more toxic than fine particulate matter from other sources, containing substances that worsen inflammation and increase the risk for developing Alzheimer’s, dementia and Parkinson’s disease.
“PM 2.5 literally just tells you the size of the particles. It doesn’t tell you what’s in those particles,” Hayden said.
The shape of the particles and what they’re made of could both contribute to negative health impacts, Hayden said. He also noted that it’s not just trees being burned in wildfires, but structures with vinyl siding, plastics and electronics like televisions, sending chemicals into the smoke plume.
How Michiganders can stay safe during a smoke wave
Although Michigan faces a future with more wildfire smoke, there’s also a growing body of research and best practices that the residents can draw on to keep themselves and their communities safe.
Hayden encouraged residents to recognize the serious risk posed by smoke and head indoors on bad air quality days, using store-bought air filters or do-it-yourself filters that can be easily and relatively inexpensively assembled with a box fan, furnace filter and duct tape.
He said residents should keep an eye on the airnow.gov website for updates on current smoke risks and air quality. Experts have advised people to wear N95 or KN95 masks outside on smoky days.
Decision makers in Michigan and other eastern states may also want to consider the work done in the West to address health risks from wildfire smoke. For example, a plan from Washington state environmental and health authorities guides schools on when they should limit or cancel outdoor activities or consider canceling school based on the government’s Air Quality Index, which assesses the risk from different pollution levels.
“It’s really hard to factor in human behavior,” Hayden said of the potential for communities to take proactive measures and limit mortality. “If everyone does take the recommended protective actions, they’re able to get inside, put on respirators, use air filters, close the doors and windows, then we might expect a lower death rate.”