Wildfires are dangerous. And some of the threats come not from the flames themselves but from inhaling the tiny toxic particles in wildfire smoke. 

“They are small enough that they can penetrate deep into the respiratory system, so they can get to the lungs, and then from there to the bloodstream, and affect other organs,” says Rosana Aguilera, a post-doctoral scholar at the University of California, San Diego. 

In a recent study, her team looked at 14 years’ worth of hospital records across a large area of Southern California. 

They found that during wildfire smoke events, hospitals had a 10% increase in admissions for respiratory conditions such as asthma and COPD.

Their findings suggest that wildfire smoke may be even more toxic than previously thought. 

The extent of the danger may vary depending on the fire’s intensity and what burned – for example, which tree species and if buildings were in the fire’s path. 

“There are other chemicals and compounds found in those buildings, so all those chemicals are released,” she says.

Aguilera says that when smoke levels are high, people should stay inside and put on a mask if they need to go outdoors, so they can breathe as little of the dangerous smoke as possible.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media