Wildfire smoke reverses progress on clean air, study shows. Here’s how it impacts Idaho

Nicole Blanchard
·2 min read

An increase in wildfire smoke over the last decade — spurred by a warming climate — is undoing years of progress on air quality in the U.S., according to a new environmental science study. Idaho is among the states bearing the brunt of the impact.

A team of environmental scientists from Stanford University created a model to determine the amount of PM2.5 particles — harmful small particulate pollutants found in wildfire smoke — present in the atmosphere on a daily basis between 2006 and 2020. The model looked at ground and satellite data to recreate the amount of smoke present each day and determine where smoke traveled.

The researchers found that the daily amount of PM2.5 particles created by wildfire smoke has increased by up to 5 micrograms per cubic meter of air in the Western U.S. since 2006. The Environmental Protection Agency’s daily standard for the pollutant — the highest level allowed per day before public health is significantly impacted — is 35 micrograms per cubic meter. The yearly average should not exceed 12 micrograms.

The study noted that the West is also seeing the biggest increase in the number of days with unhealthy levels of PM2.5, which it categorized as extreme smoke days. Those increases are particularly prevalent in states like Idaho and its neighbors, including California, Oregon, Washington and Nevada. Models from the study showed that smoke originating from wildfires in Oregon and Washington frequently ends up in Idaho.

A graphic created by a team of Stanford University researchers shows how the number of extreme wildfire smoke pollution days – when air is considered unhealthy for the general population – has increased in the West since 2006.
A graphic created by a team of Stanford University researchers shows how the number of extreme wildfire smoke pollution days – when air is considered unhealthy for the general population – has increased in the West since 2006.

The study’s authors said the impacts on air quality are a reversal from decades of air quality improvements across the U.S., thanks to stricter air quality standards and reductions in emissions. The new data reaffirms the results of a study released by Carnegie Mellon in 2019 that showed a decline in the country’s air quality after 25 years of improvements.

“People may be less likely to notice days with a modest increase in fine particulate matter from smoke, but those days can still have an impact on people’s health,” Marissa Childs, the study’s lead author, told The New York Times.

The researchers said a growing body of research points to potential health, labor and economic impacts from wildfire smoke. Recently, researchers with the University of Idaho and Boise State University began looking into how smoke could affect Idaho’s potato crops.

While the Boise area had a relatively smoke-free summer this year, local air quality experts told the Statesman last month they anticipate more smoke in the future.