Eaton Fire plume had lead levels 80 times typical, study finds

A Caltech study found that at the peak of the January 2025 Eaton Fire, about 7 million people in the Los Angeles area were in a plume with estimated 24-hour lead concentrations roughly 80 times typical levels. The estimate describes people living in the affected area, not confirmed individual exposure, and the study did not establish that anyone was poisoned or became ill. Researchers measured the plume’s chemical composition at one air-monitoring station in Pico Rivera. They compared the Eaton Fire data with measurements from a 2024 Riverside County fire that mostly burned vegetation. The Eaton plume contained about 50 times as much lead, three times as much arsenic and seven times as much halogen as the Riverside fire smoke, according to the study, published in Science Advances. The researchers used air measurements and population data to estimate the number of people in the plume’s path. The station recorded lead in fine particles; it did not measure how much any person inhaled, individual blood lead levels or health effects. The study’s findings therefore describe regional air conditions rather than personal doses or diagnoses. Lead levels rose in eastern Los Angeles and...