Wildfire toxins can linger for weeks on household surfaces: study

As smoky summers become more common in B.C., a new study shows toxins from wildfire smoke can linger on surfaces in your home for weeks.

Researchers at Portland State University looked at some highly toxic compounds in wildfire smoke and how long they remained in air filters and on common household surfaces like cotton and glass.

They found levels of polycyclic aromatic hydrocarbons (PAHs) remained elevated for weeks after exposure.

“They are associated with a wide variety of long-term adverse health consequences like cancer, potential complications in pregnancy and lung disease,” said Elliot Gall, associate professor in Mechanical and Materials Engineering at PSU. 

“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 … 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 good news is the study found common household cleaners are great at getting rid of the toxins that have accumulated on surfaces — laundering clothes or using glass cleaner on a drinking glass greatly reduced the compounds left after a simulated wildfire smoke event.

However, researchers pointed out air filters, unlike glass and cotton, can’t be cleaned and need to be replaced after extremely smoky days.

The study suggests while public messaging about wildfire smoke mainly focuses on reducing exposure by staying inside, closing windows, running air filters, and wearing a mask, we should also consider what to do after a smoke event, including cleaning surfaces.