At the height of the wildfires in Los Angeles County, atmospheric concentrations of lead, a neurotoxin, reached an average of 100 times higher even miles from the flames, according to early detailed measurements obtained by The New York Times. The level of chlorine, which is toxic even at low concentrations, reached 40 times the average.
The increased levels highlight the added danger of wildfires when cars, homes and other structures burn, researchers said. Lead is often found in paint and pipes used in older homes, and chlorine and other chemicals are formed when plastic melts or burns.
These fires were a “wake-up call,” says Haroula Baliaka, Ph.D. candidate in atmospheric chemistry at the California Institute of Technology is part of a new nationwide effort to monitor chemicals in the air in real time. They are “no longer just burning trees and grass,” he said. “They are urban fires fueled by the materials that make up our homes and cities.”
As climate change, along with new development, increases the chance that wildfires will strike more densely populated areas of the world, concerns about the spread of toxic substances will increase.
For Los Angeles, toxic smoke means that the death toll from the fires, as well as long-term health burdens, could increase. Breathing in lead can damage the brain and nervous system, especially in children. Airborne lead levels observed during the fires were more than three times the safety limits set by the Environmental Protection Agency. Chlorine can damage the lungs and airways.
In general, high levels of particulate matter in wildfire smoke are associated with increased risk cardiovascular and respiration diseases and death.
The latest measurements come from a new federally funded national monitoring network GOODlast year began measuring a wide range of air pollutants in real time. Readings from fires in the Los Angeles area were recorded at the network's monitoring station in Pico Rivera, several miles from active fires.
Nga Lee Ng, an atmospheric scientist at the Georgia Institute of Technology and the network's principal investigator, who also goes by the name Sally, said wildfires are more of a focus for scientists studying air pollution. Professor Ng said the urban nature of many of these fires meant the smoke would have “very different components, more toxic particles”.