According to a new study, increasingly fierce forest fires in the western United States are affecting the region’s air quality, as wildfires now account for half of air pollution during the worst years of the year. ‘fires.
Scientists at Stanford University and UC San Diego have found that toxic smoke feathers, which can cover western states for weeks as forest fires are extinguished, are reversing decades of gains in reducing pollution. of the air. Although heat deaths were previously predicted to occur as the worst consequence of the climate crisis, researchers say air pollution caused by smoke could be just as deadly.
“For many people in this country, forest fires will be the way they experience climate change,” said Marshall Burke, an associate professor of earth sciences at Stanford and one of the study’s authors. “The contribution of forest fires to poor air quality has doubled in the last 15 years in the west.”
Fine particulate air pollution, known as PM2.5s, was already known to take four months to the lifespan of average Americans. And health researchers are just beginning to understand the dire health consequences added by the increased exposure to smoke from large stretches of the American population.
Forest fire seasons have become increasingly brutal in the American West, exacerbated by the climate crisis. The 2020 fire storms were among the worst in recorded history, with 31 people killed, 10,000 buildings destroyed or damaged and more than 4 acres burned in California alone. Large strips of Colorado, New Mexico, and Arizona were also burned.
After California residents endured a month of orange-brown air full of small dangerous particles, another group of Stanford researchers tracked the dramatic increase in hospitalizations for things like strokes, heart attacks and asthma.
Bibek Paudel, a postdoctoral researcher at Stanford Asthma Clinic, found that hospitalizations for stroke and related conditions increased 60 percent in the five weeks following lightning-related fires that began sending smoke into northern California. last August. The number of missed pregnancies also doubled in the weeks following the fires, a surprising finding that researchers are still interpreting. Paudel also found significant increases in heart attacks and juvenile hospitalization for respiratory diseases.
“I don’t think people know the long-term effects of fire smoke on health,” said Mary Prunicki, research director at Stanford’s Sean N Parker Center for Allergy & Asthma Research.
For decades, air quality in the United States has improved due to reductions in vehicle and factory pollution, required by the Clean Air Act. But in the last 40 years, the amount of land burned in forest fires has quadrupled, according to Burke’s study.
The study, published in the Proceedings of the National Academy of Sciences, combined data from satellite images of smoke plumes with measurements obtained from ground-based air monitors, which record local air pollution, to model the total exposure to smoke. The study included all states west of (and including) New Mexico, Colorado, Wyoming, and Montana.
Satellite images can detect smoke plumes as they travel across the country. But it is difficult to know if they are low enough to affect ground air quality, so the study created statistical models of how pollution changed at specific locations after fire events, combining satellite information Beds, air monitors and data models.
“Everyone knows that fires produce dirty air, so it’s no surprise,” Burke said. “What we have been able to do in this study is quantify the importance of this contribution. And we’ve found that it’s really investing a lot of the progress that’s been made across the country in improving air quality. ”
Surprisingly, the study found that fire smoke spreads the effects of air pollution to whiter and richer populations. Historically, low-income communities have been hardest hit by air pollution, often because their homes are closer to highways and factories. But smoke spreads pollutants over much wider areas. Burke said the western United States, where more forest fires occur, is also usually whiter and richer than other regions of the country.
As feathers travel the country, pollutants can harm even people living away from fires, in the midwest or east.
“Fire smoke is a load that is distributed much more evenly than the rest of the pollution,” Burke said.
However, other research has shown that low-income populations may be more affected when smoke blankets a region, because their smaller, older homes offer them less protection.
Ironically, one of the future solutions to all this smoke may be to light more fires.
The increase in forest fires is due in part to warmer temperatures and drier conditions, but there is a growing consensus that it is also the result of national fire suppression policy, rather than occasionally letting the fire burn. land.
“There’s a lot of fuel on the ground,” Burke said. “Climate change is drying it up and making it much more flammable.”
Burke said the policy of using prescribed burns, which involves lighting carefully controlled fires to clean up part of the brush, could be an important strategy to reduce forest fires and reduce exposure to hazardous smoke in the coming years.
“The benefits can be quite large, but there are several key issues that need to be studied,” he said.
Otherwise, “in regular business, years like 2020, which historically wasn’t in the rankings, can become much more than the norm,” he said. “It’s a terrible thing to think about.”