Toxic fallout from LA fires will damage both land and sea

SANTA MONICA, Calif. ? The dolphins splashing in the sparkling waters off the Pacific Coast Highway are soon going to get an unwelcome ? and unhealthy ? surprise.
Next time it rains, miles of canyons and hillsides charred by wildfires will send debris rushing down ravines and through drainage ditches into the Pacific Ocean.
"It’s devastating, devastating," said Marjan Khonsari, a 30-year Santa Monica resident and co-founder of Kapowui Surf Lessons. "The whole ecosystem is going to change."
The wildfires of the past two weeks will leave Los Angeles with an unprecedented environmental catastrophe that will linger for years, experts say, from the toxic ash settling in backyards and playgrounds to asthma attacks, drinking water contamination and even an increased risk of dementia, which studies have tied to wildfire particulate exposure.
Human swimmers and surfers have already been told to remain out of the water, and the toxins will likely have long-term impacts on water quality and marine life, including on dolphins.
The debris from 12,000 burned houses and businesses is so toxic that homeowners could be banned from cleaning up their own property. Based on how authorities have handled similar ? but smaller ? fires, homeowners may be required to depend on specially certified workers to sift through the debris for any remaining valuables and to ready sites for reconstruction.
In many cases, people who can't or don't want to rebuild will become part of the growing number of climate refugees forced to relocate following natural disasters supercharged by climate change.
It all hits particularly hard in a environmentally conscious, health-forward community, where coffee shops offer both recycling and composting, restaurants warn diners that fried food can cause cancer and birth defects, and parking garages have signs warning people that car exhaust can make you sick.
But these wildfire toxins, which include benzene, styrene, formaldehyde and cadmium, aren't the kind of chemical that can be easily purged with a $16 "Royal Defense" smoothie from upscale grocery Erewhon. A 2024 study found that wildfire smoke already kills an estimated 10,000 Californians annually, compared with 4,000 traffic-related deaths.
Downhill into Santa Monica Bay
Four narrow, twisting road miles up to nearly 1,000 feet above the ocean, smoke rose over the small mountain community of Topanga this week. A longtime hippie gathering spot, Topanga escaped the worst of the Palisades Fire. But flames did engulf some houses and burn through the canyon that connects to the Pacific Coast Highway.
Between distributing gas, coffee and propane to cut-off residents, community volunteer Seth Monk, 41, worried about the impacts downhill. Any debris caught by the rain will wash straight down the canyon, beneath or over the Pacific Coast Highway, and right into Santa Monica Bay. At the fire's worst, he said, it looked like a volcano exploding above the canyon.
"So much of the forest and the wildlife has been burnt down," said Monk, a meditation teacher. "All that stuff's just going to go into the ocean."
Topanga Canyon is no stranger to mudslides and rockfalls. The road carved up the canyon was closed for months last summer after heavy rains sent a cascade of rocks across the pavement, forcing residents to make a lengthy detour to reach Santa Monica. In the days after the Palisades Fire, rocks again began tumbling onto the road, blocking portions of lanes in several locations.
"We are due for some rain and it’s going to be really bad," said Khonsari, the surf-shop founder. "Once it rains, everything is going to run into the ocean."
Asbestos kitchen tiles turned to dust, cars burned to their frames
The lack of rain this winter played a significant role in allowing the Palisades Fire to grow so big, so fast. After several years of wet winters that spurred the growth of brush and grass, the rain stopped and the vegetation dried out.
Beverley Auerbach and her husband lived in Pacific Palisades since 1980, and they'd seen many fires encroach over the years. But when they got the alert to prepare for evacuation, they preemptively packed up their cars and headed toward Santa Monica.
The 1.5-mile drive from their Palisades home down to Temescal Canyon usually takes about six minutes. It took Auerbach 45 minutes this time. And she was one of the lucky ones. Dozens of her neighbor who waited until later were forced to abandon their cars in a traffic jam on the short stretch of road, running to safety before the fire torched them.
All across Palisades, burned-out cars sit on melted tires, their aluminum engine blocks puddled onto the ground. Electric cars and their batteries filled with rare earth elements burned to their frames.
Auerbach's house was one of hundreds destroyed by the fire, along with the houses of 30 of her friends and neighbors in the Alphabets neighborhood. Ironically, she said, they'd all talked for years about how to live more eco-conscious lives. Many people bought electric cars, installed solar panels, reduced their yard water use, she said.
She's not in a rush to get back to the neighborhood, though: In the 1990s, she and her husband removed the asbestos kitchen tiles installed in the house when it was built, but many of her neighbors hadn't. Thinking about the contamination in their neighborhood, she wondered how it will all get cleaned up: "It's full of plastic, asbestos, all kinds of stuff."
Residents face cleanup of 'highly toxic' debris
Officials have not yet said when residents of the Palisades and other hard-hit areas may be allowed to return, in part because they are likely still developing a protocol to manage an influx of grieving people to places that are dangerous to be around.
Public health authorities have already banned people from using leaf blowers to clean up ash because of the inhalation risk, and are advising returning residents to wipe down countertops and other surfaces, and to use a mop to remove ash from floors, instead of a vacuum.
"Windblown dust and ash contain small particles that may cause irritation or exacerbate pre-existing health conditions, particularly for children, older adults, pregnant individuals, and those with heart or lung conditions," the Los Angeles County Public Health Department said.
Residents whose homes survived are eager to return to their property, belongings and normal routine. And those who lost their houses are eager to scour the debris fields for belongings that might have survived, from jewelry locked in fireproof safes to beloved art or vintage cars.
One expert told USA TODAY that residents should start thinking about their neighborhoods in terms of the dangerous "burn pits" once used by the military in Iraq and Afghanistan to dispose of waste. Another said residents should avoid even touching the remains of their homes.
"Residents should not, not, not, go home and sift through the debris," said Katie Arrington, a disaster recovery expert who has been helping manage the aftermath of a suburban Denver 2021 wildfire that destroyed about 1,000 homes. "It is highly toxic debris. It’s the mixing all the materials together, along with it burning. It’s not just your house, but your neighbor's houses, your car in the driveway."
Arrington, who works for Boulder County's Recovery and Resiliency Division, said just removing the debris from homes destroyed in the 2021 Marshall Fire took six months, and required the expertise of contractors licensed to handle the waste.
In most cases, she said, workers had to remove at least three inches of dirt from people's yards in order to reduce the ash and toxin contamination to acceptable levels. That work, which averaged $40,000 to $60,000 per house, was funded by a combination of homeowners insurance and federal, state and local grants.
"That is going to be critical for anyone who wants to rebuild, for animals and kids and for the future," Arrington said.
'Toxic chemicals deposited all over Los Angeles'
Experts say the severity of wildfires across the United States, particularly in the west, have been growing because of climate change. But there's also been increasing risk along what's known as the wildland-urban interface, putting more and more homes in danger.
While scientists have a good handle on the problems posed by wildfire smoke that comes from burning vegetation, there's relatively little research yet complete on the effects of large-scale urban fires.
Environmental toxicologist Luke Montrose, an assistant professor of environmental and radiological health sciences, studies the impact of wildfire smoke on people and communities. He said studies have shown the health risks wildland firefighters are exposed to ? almost none ever wear any sort of respirator or N95 mask even during the thickest smoke ? and worries about the risks residents face when wildfires torch entire neighborhoods.
A study of Montanans exposed to wildfire smoke for six weeks in 2017 found their lung function was impaired for at least two years following that exposure, Montrose said. And that was just smoke from burning trees ? not houses or cars or grocery stores.
"In general, this is more similar to burn pit exposures than it is to forest fires," he said of the Palisades and Eaton fires. "It's just a pile of garbage that's being burned and when that fire rips through houses and cars and trees, it's going to be putting out more and varied toxic chemicals. … You add in heavy metals, things like lead, all of your building materials, foams and plastics and carpet and asphalt."
David Michaels, the former head of federal workplace safety regulator OSHA said authorities face tough decisions in the coming days, weeks and months. Scientists know the debris is toxic, and so is the ash coating the homes that remain standing, but residents need to go home soon, he said.
"This is ash that’s contaminated with huge numbers of toxic chemicals, being deposited all over Los Angeles, including playgrounds and backyards. And children’s bodies are at much greater risk," said Michaels, a professor at George Washington University School of Public Health and a commissioner with the National Commission on Climate and Workforce Health.
Michaels said the United States needs to have a reckoning both about the risks and the causes of these urban firestorms. Employers, he said, must accept that workers cannot be forced back to their jobs while such high health risks remain, and society needs to come to terms with the reality that climate change is making such fires worse.
"We haven’t recognized this as a national problem in the United States yet and we need to. Many of our nation's residents are having their lives disrupted and impacted by the climate crisis and we have a responsibility to take care of them," he said. "The impacts, especially on children, will be very great."
Marine life at risk
In Santa Monica, the sparkling waters that draw surfers, swimmers and anglers represent decades of painstaking work by nonprofits like Heal the Bay to reduce pollution and runoff. Over the past several decades, marine life has rebounded. Dolphins are no longer a rare sight, but frequent and curious companions to surfers riding the waves rolling off the Pacific and onto the coast's miles of sandy beaches.
Marine-life experts say the toxic runoff can have both acute, immediate impacts on the fish and other aquatic life living in the bay, along with long-term impacts like widespread die-offs. The scope of the damage will depend on how much runoff occurs.
Environmental advocates are also worried about the impact of Gov. Gavin Newsom's decision to temporarily suspend some coastal environmental regulations in the name of speeding recovery and rebuilding efforts.
Khonsari, the surf shop founder, said she's had to cancel hundreds of lessons already, keeping her instructors safely on shore so they don't get eye infections or worse from contaminated water. With the COVID-19 pandemic squarely in the rearview mirror and tourism rebounding, she'd planned on 2025 being a boom year.
And then the Palisades burned.
"Everything was just going in such a positive direction and it’s going to be utterly devastating to see what happens to the marine life," she said. "We are due for some rain and it's going to be really bad."
This article originally appeared on USA TODAY: How toxic debris from LA fires could ignite another disaster