Risks from ash and air pollution remain for people returning after wildfires. Here’s how to stay safe

As people return to the structures spared from Los Angeles wildfires, experts warn that they should be careful of the air inside and be especially cautious when cleaning up. Smoke, ash and all the toxic chemicals that come with both can seep into even well-sealed homes.

As some people return to the structures spared from Los Angeles wildfires, experts warn that they should be careful of the air inside and especially cautious when cleaning up. Smoke, ash and all the toxic chemicals that come with both can seep into even well-sealed homes and pose risks to health. “There’s a lot that has potentially happened to affect poor air quality in your home, even if you haven’t suffered any physical damage to the home itself,” said Katherine Pruitt, national senior director for policy at the American Lung Association. “The fumes and the ash, the particles that are going to be in your indoor environment, are not safe to breathe. You especially don’t want to come into contact with the ash in your lungs, eyes or skin.” Los Angeles Public Health has declared a local health emergency for the entire county due to the fires. It prohibits the use of air blowers, including leaf blowers, in order to reduce health risks due to the ash and particulate matter from smoke. Wildfires burn a lot more than trees and grass. The burned cars and structures can release toxic chemicals. Even after fires die down and smoke dissipates, walls, floors, furniture and other indoor surfaces may absorb toxic chemicals and smoke. These surfaces can off-gas for weeks or even months, studies show, although that will reduce over time. Wildfires contribute to harmful fine particle pollution, which is at levels bad for human health in the area even before the wildfires. The American Lung Association’s State of the Air report for 2024 listed the Los Angeles area as one of the top 10 cities polluted by year-round particle pollution. It’s been No. 1 for ozone pollution for decades, Pruitt said. With the wildfires now on top of that, the air quality index has been sitting at “unhealthy” levels for many parts of Southern California for several days.