Millions Of Residents Exposed To Toxic Metals From LA Fires, Study Shows
As homes ignited and burned down during the 2025 Los Angeles fire, millions of California residents were exposed to a high concentration of airborne toxic metals, a new study discovered.
As homes ignited and burned down during the 2025 Los Angeles fire, millions of California residents were exposed to a high concentration of airborne toxic metals, a new study discovered.
Almost two years ago, wildfires spread through southern California killing at least 31 people and destroying 16,000 structures — but the extent of the blaze’s far-reaching effects remained unclear. Researchers measured the chemical signatures emitted between urban fires and wildfire smoke to find approximately 7 million Californians inhaled deadly heavy lead poisoning in the air during the first 24 hours of the devastating fires, a study published Wednesday in Science Advances found.
Researchers measured particles present in the smoke every hour during the fires’ blaze and recorded the data in the Atmospheric Science and Chemistry mEasurement NeTwork (ASCENT), according to the study.
ASCENT is the U.S.’s first measurement network able to measure the chemical composition of airborne particles in real time, a researcher told the Associated Press.
The researchers compared the chemical makeup of the smoke from the LA fires with smoke from a 2024 wildfire in Riverside County which mostly burnt vegetation, the study reported. By contrasting the measurements in these two smoke plumes, scientists found the LA fire contained 50 times more lead, three times more arsenic and seven times more halogens. At the peak of the burning, about 7 million people were exposed for a full day to lead levels more than 80 times the typical average, the study found.