Four decades’ worth of data from the National Interagency Fire Center shows that while the annual number of wildfires in the U.S. has remained relatively around the range of 70,000, their intensity and consumption of acreage both increased.
That’s according to researchers at Oregon State University, who said this uptick also applies to the frequency of wildfire smoke, a development that endangers kids in public schools and childcare centers.
Researchers studied air quality data in the U.S. from 2006 to 2023, and saw that the average number of smoky days at public schools shot up from 6.8 a year to 54.4. For childcare facilities, the spike went from 9.4 to 112.2.
And while many wildfires occur in the western states, wind can spread harmful smoke and other particulate matter across hundreds, even thousands of miles, said Molly Kile, an environmental epidemiologist with the OSU College of Health.
“And the prevailing wind blows from west to east, so it all goes downwind,” she said.
Children and infants are particularly susceptible to wildfire smoke, explained Kile. “They have a higher inhalation rate, meaning that they breathe in more air per pound of body weight than an adult does. And also their bodies are still growing, so as a life stage they’re uniquely vulnerable.”
Particulate matter of 2.5 micrometers or smaller – referred to as PM2.5 – can be inhaled deeply into the lungs and even enter the bloodstream, an OSU news release states. “It is a known cause of cardiovascular disease and is linked to the onset and worsening of respiratory illness.
“As climate change exacerbates wildfire risk, PM2.5 emissions from fires have surged to the point that wildfires now account for almost half of all PM2.5 across the United States and have negated air quality improvements in multiple regions,” the OSU release continues..
Kile said there’s an environmental justice angle as well.
“We found that rural schools and also those schools that were serving low-income students were experiencing more smoke days compared to the urban schools, or those schools that had higher income,” said Kile. “So it is also about trying to get resources ideally, where it's needed the most.”
Stephanie Foster, the study’s corresponding author and scholarly activity program manager in Samaritan Health Services’ Research Development Office, stated that due to the amount of time students spend in schools and childcare centers, those places are important for safeguarding children’s health.
“We found that the buildings where children spend much of their day do not consistently protect them from air pollution,” Foster said in the release. “But educational facilities are places where coordinated preparedness plans, air filtration, indoor air quality monitoring and changes to activities during smoke events could reduce exposure.”
Kile said this is a solvable problem, with educators and childcare operators putting in new or upgraded air purification and HVAC technology if funding allows.
Other partners in the study included Andrew Larkin, Megan MacDonald, Megan McClelland and Perry Hystad of the OSU College of Health and Parichehr Salimifard of the OSU College of Engineering. Their research was supported by the National Institute of Environmental Health Sciences.
The full research is outlined in the latest edition of the journal, Environmental Research.
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