Eaton Fire smoke exposed 7 million residents to lead 80 times above normal, study finds
Caltech-led research in Science Advances links the toxic January 2025 plume to burning homes, vehicles and infrastructure
A study published in Science Advances finds that smoke from the Eaton Fire, which tore through Altadena on 7 January 2025, carried airborne lead roughly 80 times above normal atmospheric levels, exposing about 7 million Los Angeles residents to concentrations above 50 nanograms per cubic meter on 9 January. Led by atmospheric chemists Haroula Baliaka and Nga Ng at the California Institute of Technology, the research attributes the toxic load to the urban fuel burned: homes, vehicles and infrastructure rather than vegetation.