Study Identifies Best Ways to Clean After a Wildfire

According to science and technology news website Phys.org, a recent study has helped identify the best ways to clean surfaces tainted with toxic compounds that remain after a wildfire event.

The study was published in the peer-reviewed journal Environmental Science & Technology by Elliott Gall, an associate professor in mechanical and materials engineering at Portland State University in Portland, Oregon. Researchers looked at the length of time polycyclic aromatic hydrocarbons (PAHs), which are harmful chemicals found in wildfire smoke, persisted on glass, cotton, and air filters, and how they could best be removed from those surfaces.

“[PAHs] are associated with a wide variety of long-term adverse health consequences like cancer, potential complications in pregnancy, and lung disease,” Gall told Phys.org. “So, if these compounds are depositing or sticking onto surfaces, there are different routes of exposure people should be aware of. By now, most people in Portland are probably thinking about how to clean their air during a wildfire smoke event, but they might not be thinking about other routes of exposure after the air clears.”

The study revealed that PAHs can remain at elevated levels on surfaces for weeks after an extreme smoke event—time that could also expose building occupants to increased health risks from the compounds.

But by laundering cotton materials just once, PAH levels were reduced by 80%. Via the use of a commercial glass cleaner, PAH levels on glass were reduced between 60% and 70%.

However, since air filters can’t be cleaned, there’s no choice other than throwing away and replacing filters after a wildfire event.

“Even if there’s potentially some more life in them, over time PAHs can partition off the filter and be emitted back into your space,” Gall told Phys.org.

She added that future studies were being planned to learn more about removing PAHs from other indoor surfaces, such as drywall or ceramic.