Climate LA Wildfires Air Pollution

During the peak of the 2025 Los Angeles fires, approximately 7 million residents were exposed to airborne lead concentrations over 24 hours that exceeded 80 times the normal background level, according to a new study published Wednesday in the journal Science Advances. Researchers from the California Institute of Technology compared the chemical composition of the plume from the Eaton fire with smoke from a fire that mostly burned vegetation and found that the urban smoke had more lead, arsenic and other toxic metals linked to burning vehicles, building materials and electronics. The study authors say smoke exposure frameworks and emergency response protocols should be revised as more fires burn into cities due to climate change and urban expansion.