Chronic exposure to pollution A new study shows that wildfires are linked to tens of thousands of deaths annually in the United States.
The study, published Wednesday in the journal Science Advances, found that from 2006 to 2020, long-term exposure to small particles from wildfire smoke contributed to an average of 24,100 deaths annually in the lower 48 states.
“Our message is: Wildfire smoke is very dangerous. It is an increasing threat to human health,” said Yaguang Wei, study author and assistant professor in the Department of Environmental Medicine at the Icahn School of Medicine at Mount Sinai.
Other scholars who have studied the death toll from Forest fire smoke We were not surprised by the results.
“Their estimates are reasonable,” said Michael Jerrett, a professor of environmental health sciences at the University of California, Los Angeles, who was not involved in the study. “We need more of them. Only if we conduct multiple studies with many different designs do we gain scientific confidence in our results.”
In this paper, the researchers focused on deaths associated with chronic exposure to fine particulate matter, or PM2.5 – The main concern is forest fire smoke.
These particles can settle deep in the lungs and enter the bloodstream. Short-term exposure can cause coughing and itchy eyes, but in the long term, it can exacerbate existing health problems and lead to a range of chronic and fatal health problems, including respiratory disease, cardiovascular disease, neurological disease, and premature death.
“PM2.5 wildfire smoke has emerged as a major environmental hazard in the United States, and is driven by increased frequency and severity of wildfires due to… Climate changesaid Min Zhang, a postdoctoral student at the Icahn School and author of the study.
Coupled with decades of forest mismanagement, increased development in fire-prone areas has expanded the “wildland-urban interface,” increasing the risk of wildfires with real consequences for human health, Jerrett said.
“Nobody’s going to have ‘death by wildfire’ on their death certificate unless they’ve actually been burned by a fire or a tree has fallen on them or something like that,” Jerrett said. “But many of the people who die from this exposure are actually more vulnerable. This is a real life lost. This is not an abstract, arbitrary statistical concept.”
The study authors analyzed the relationship between average annual exposure to PM2.5 from wildfire smoke and deaths by county in the lower 48 counties. They used federal mortality data across 3,068 counties for all causes of death and several specific causes — circulatory, neurological and respiratory diseases, as well as mental and behavioral disorders, tumors, endocrine, nutritional and metabolic diseases.
They also included deaths related to falls and transportation accidents — which are unlikely to be related to wildfire smoke — to ensure their observations were not biased by other things.
“We found no association between car accidents and falls, while we found statistically significant effects for other diseases,” Wei said. Deaths from Nervous Diseases saw the greatest increase with exposure to these particles.
How clear the association between particulate matter exposure and death varies by season and demographics. A stronger association emerged during colder periods, and people in rural areas and younger communities appeared to be more at risk.
The researchers also found that for every 0.1 microgram per cubic meter increase in PM2.5 in all these places, about 5,594 people die each year.
Jerrett said the study made use of a large population and that it included most causes of death in the United States, but he said the county-level data could have led to over- or under-estimates because wildfire smoke is so dynamic. “It doesn’t just cover a large county at one time. There will be parts of the county that will make it much worse.”
He added that the study also did not take into account other important factors, such as whether the person was a smoker or not.
“I really like that they looked at both smoke and non-smoke PM2.5,” said Kai Chen, an associate professor of environmental science at the Yale School of Public Health who has also studied the topic. Various research has found that PM2.5 from wildfire smoke has greater health impacts than pollution from other sources, such as automobile emissions, Chen, who was not involved in the study, said in an email.
the The Trump administration is rolling back climate change policyAlthough the most destructive wildfires are becoming more frequent, largely due to global warming, they pose serious risks, the study authors said. Quantifying the deadly threat that wildfire-generated PM2.5 poses to human health demonstrates the need for effective and urgent mitigation strategies, supported by EPA monitoring and regulation, they said.
Chen agreed, saying: “This highlights the importance of controlling wildfires caused by PM2.5, which are not currently regulated by the EPA as they are typically viewed as natural disasters.”
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