A Caltech study estimates nearly seven million people breathed lead concentrations 80 times normal background for 24 hours. It measures exposure, not clinical cases, and shows that burning cities produce smoke unlike wildland fire.
Air quality turned moderate Friday as particles were trapped near the ground, while weekend heat raised ozone risk. The temporary preventive alert called for extra care by children and people with respiratory conditions.
Scripps researchers identified sediments near pH 12 and brucite around barrel-like objects between Palos Verdes and Santa Catalina. The finding confirms persistent alkaline chemical contamination, while its ecological scale and any food-chain risk still require investigation.