The destruction caused by wildfires on the West Coast is highly visible, immediate, and relatively localized to the vicinity of the blazes.
But the dangers of air pollution from the smoke generated by the fires can be more widespread and long-term, potentially impacting Central Illinois.
University of Illinois finance professor David Molitor is also the director of the Health Care Research Initiative at the university’s Gies College of Business.
“When the wildfire burns, it produces these smoke plumes that, depending on the wind patterns, can drift for hundreds or even thousands of miles from their source,” said Molitor.
“We have found that over the past decade or so, on average, most parts of Illinois experience 40 or more days of smoke per year.”
Molitor says air pollution studies have found that particulate matter is the most harmful substance we breathe. He says over the past few decades, air quality in the U.S. has improved dramatically through efforts to reduce things like vehicle emissions and pollutants from power plants.
That leaves natural occurrences, such as wildfires, as a primary source of particulate matter.
“When you measure how much of this particulate matter comes from smoke, just of all the different sources of particulate matter, it's almost 20% of the particulate matter in the air is coming, we estimate, from wildfire smoke,” said Molitor. “So, wildfires, it turns out, are just a really important source of this of air pollution. It's not just an issue for the West Coast or certain parts of the country; the smoke really is an issue all across the United States.”
It's an issue, Molitor says, that can lead to a range of health concerns.
“These tiny particles that, when inhaled, go deep into the lungs, can penetrate the cell membranes, get into the bloodstream, and they cause stress at the cellular level throughout the body,” he said. “When people are exposed to higher levels of fine particulate matter, there's a whole host of adverse health outcomes that it can cause: Respiratory issues, heart attacks, even recent research suggests that there can be effects on brain health.”
Molitor says wildfires in North America generally occur in California, the Pacific Northwest, and western Canada. But then the health threats they exacerbate tend to spread widely.
“For any particular fire, there's kind of two things that matter for smoke. One is, how much smoke is the fire producing? It turns out these fires are producing a lot of smoke,” said Molitor. “Then the second thing is the wind patterns, which way is the wind blow? Prevailing winds in the United States, on average, they tend to go from west to east and, to some extent, from north to south.”
He says the possible health concerns in the middle of the country from fires burning far away can come as a surprise or an afterthought for many.
“I think if you were to ask most people that live in the Midwest, even to say how many days in a year do you think Illinois is covered by a smoke pool, I think 40 days of smoke would surprise most people [as] being pretty high,” he said.
Molitor says varying densities of the wildfire smoke still have similar levels of health risks.
“I knew that exposure to wildfire smoke could have some pretty serious health consequences. But I was curious, ‘Is that only coming from the really thick smoke? What about the lighter smoke?’” he said. “If you look at the impact that light, medium and thick plumes have on pollution levels, the medium and thick plumes carry substantially more air pollution than the light smoke plumes.
“So then we turn to the health impacts to say, ‘Well, if you have a thick plume that carries five times as much pollution as a light plume, does the thick plume have times bigger health impacts than the light plume?’ And it turns out that the answer is no. The thick plumes are worse for your health than light plumes, but they're actually not that much worse. The health impacts kind of level off.”
