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Mason professor warns of health risks from Western wildfire smoke

September 25, 2020

Daniel Tong, an associate professor of atmospheric chemistry and aerosols in the Department of Atmospheric, Oceanic and Earth Sciences, is advising local residents to limit their outdoor activities because of the smoke from the Western fires.

Smoke from the enormous wildfires raging on the West Coast has made its way to our region, and a George Mason University researcher is warning residents in the metropolitan Washington, D.C., area to be very careful. 

Daniel Tong, an associate professor of atmospheric chemistry and aerosols in the Department of Atmospheric, Oceanic and Earth Sciences within Mason’s College of Science, is advising local residents to limit their outdoor activities because of potentially damaging particles mixed in with the smoke from the fires. 

“Smoke like this is made of very fine soot, which can go all the way down to the bottom of your lungs,” Tong said. “Even if the air quality reading is good, it only represents one aspect—mass concentration—of the aerosols. In fact, there are a lot of tiny particles suspended in the air.” 

Several of the nation’s Western states have been burning like never before in recent weeks, emitting a vast amount of black carbon (soot) and other particles into the air. Tong said that it generally takes a week for those particles to cross the continent and reach the East Coast. The smoke initially stayed high in the atmosphere, but has made its way to the ground in recent days, resulting in hazy conditions and more orange and red sunsets. 

Tong recommended that residents take extra precautions, as the conditions will last a few days unless washed out by rain or pushed away by clean air. 

“Note that masks for COVID-19 will not help—the particles are too fine to be filtered out,” he said. 

Daniel Tong can be reached at

For more information, contact John Hollis at 571-396-1578 or

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George Mason University is Virginia’s largest public research university. Located near Washington, D.C., Mason enrolls 38,000 students from 130 countries and all 50 states. Mason has grown rapidly over the past half-century and is recognized for its innovation and entrepreneurship, remarkable diversity and commitment to accessibility.