Thousands of firefighters have been battling wildfires across 45 square miles of densely populated Los Angeles County. The two largest fires, the Palisades Fire in Pacific Palisades and the Eaton Fire near Pasadena, remain active. One of the latest, the Hughes Fire in the Castaic area, has prompted evacuation orders for tens of thousands of people.

The death toll from the wildfires plaguing the Los Angeles area in the United States has risen to 29. The coroner’s office announced on Monday evening that one person died in hospital over the weekend as a result of the “Palisades’’ fire on the western edge of Los Angeles.

One of the biggest cleanup challenges from the Southern California fires is lithium-ion batteries, which can explode after damage or exposure to heat. The batteries are found in electric vehicles, which abounded in some burned neighborhoods, including Pacific Palisades.

Scientists have linked a lithium battery plant fire in California earlier this month to a surge in heavy metals found in nearby soil.

Elevated concentrations of heavy metals have been detected at the Elkhorn Slough Reserve by scientists from San Jose State University.