Tens of millions of Americans experienced at least a day last year shrouded in wildfire smoke. Entire cities were blanketed, in some cases for weeks, as unprecedented wildfires tore across the Western U.S., causing increases in hospitalizations for respiratory emergencies and concerns about people’s longer-term health.
A new study finds those concerns are well founded.
Researchers with the Scripps Institution of Oceanography at the University of California, San Diego say that the tiny particles released in wildfire smoke are up to 10 times more harmful to humans than particles released from other sources, such as car exhaust.
The research, published in the journal Nature Communications Friday, paints a worrisome picture for Americans living on a fire-prone continent, especially as climate change amplifies fire risk worldwide.
“[Air pollution] has been decreasing in some regions of the U.S.,” says Rosana Aguilera, a postdoctoral scholar and one of the study’s co-authors. “This is not the case in wildfire-prone areas.”
Aguilera and co-author Tom Corringham looked at hospital admissions data over 14 years in Southern California and compared that to spikes in air pollution during strong wind events. They found that pollutants from wildfire smoke caused up to a 10% increase in hospital admissions.
“We’re pretty aware of the physical costs of wildfire, in terms of firefighting costs and damage to property,” Corringham says, referencing the more than $10 billion lost in damages and efforts to corral California’s fires last season. “But there’s been a lot of work that has shown that the health impacts due to wildfire smoke are on the same order of magnitude, or possibly even greater, than the direct physical cost.”
The findings are particularly concerning, he says, given the increase in wildfire activity that California and other states have experienced in recent years, and the expectation that wildfires will become more intense and frequent as the climate warms.
An NPR analysis of air quality on the West Coast found that 1-in-7 residents experienced at least one day of unhealthy air conditions last year. For weeks, the smoke was so thick in parts of Oregon, Washington and California that public health officials urged people to stay indoors and avoid physical activities. That smoke drifted east, creating hazy skies and an oddly vibrant sun as far away as the East Coast.