The spiking levels underscore the added danger from wildfires when cars, homes, and other structures burn, researchers said. Lead is often present in paint and pipes used in older homes, while chlorine and other chemicals are generated when plastic melts or combusts.

Extreme fire growth’ warnings in place as firefighters battle new blazes - Evacuation orders have been issued as a new brush fire explodes near the U.S.-Mexico border, while Donald Trump expected to s