Air Levels of Lead and Chlorine Soar as LA Wildfires Burn

At the height of the Los Angeles wildfires, atmospheric levels of lead, a neurotoxin, reached 100 times higher, even miles away from the flames, as measured by first details obtained by The New York Times. Chlorine levels, which are also toxic at low concentrations, reached 40 times the average.

The spiking levels highlight the dangers of wildfires when cars, houses and other structures burn, researchers said. Lead is often found in paint and pipes used in older homes, but chlorine and other chemicals are released from plastics when they melt or burn.

These fires are an “awakening,” says Haroula Baliaka, Ph.D. candidate in atmospheric chemistry at the California Institute of Technology, who is part of a new nationwide effort to monitor airborne chemicals in real time. “They are no longer just burning trees and grass,” he said. “They are urban wildfires, fueled by the materials that make up our homes and our cities.”

As climate change, along with new developments, increases the risk of wildfires in densely populated areas of the world, concerns about toxic emissions may increase.

For Los Angeles, the toxic smog means the death toll from the fires could increase, as well as the long-term health burden. Breathing in lead can damage the brain and nervous system, especially in children. The level of lead in the air found during the fire was three times the safety limit set by the Environmental Protection Agency. Chlorine can damage the lungs and respiratory system.

In general, high levels of smoke pollution are associated with increased risk of cardiovascular and respiratory disease and death.

The latest measurements come from a federally funded national monitoring network called ASCENT, started last year to measure a variety of air pollutants in real time. The readings from the Los Angeles County wildfires were taken from the network’s monitoring station in Pico Rivera, several miles away from the active fire.

Forest fires are becoming a bigger focus for scientists studying air pollution, said Nga Lee Ng, who also uses the pseudonym Sally, an atmospheric scientist at the Georgia Institute of Technology. and principal investigator in the network. The urban nature of many of these fires means the smoke “will have a very different composition, a lot more particulate matter,” Professor Ng said.