Posted by Jonathan Portney on March 25, 2025
The Los Angeles wildfires have faded from the headlines, but their aftermath lingers—literally and figuratively—in the ash and soot now scattered across beaches and neighborhoods. As I dug into recent reports, two threads stood out: the hidden risks of post-fire contaminants and the growing role of global information systems in keeping us safer from future blazes. Here’s what I found, and why it matters.
The Palisades and Eaton wildfires torched 16,200 structures, leaving behind more than just charred rubble. Conservation biologist Ashley Oelsen, part of the Santa Monica Commission on Sustainability, has been on the case, spending $8,000 of her own money to test beach samples along Santa Monica. Her findings? Traces of heavy metals (copper, lead, zinc, aluminum), asbestos, lead paint, and even residues from lithium batteries in electric vehicles and solar panels. While these levels fall below official hazardous thresholds so far, the long-term health risks—like cardiovascular disease and reduced lung function—keep experts like Oelsen on edge.
The Los Angeles County Public Works ran its own tests in early March 2025, finding no hazardous waste in the debris, though minor traces of asbestos and heavy metals showed up (Capital & Main). Still, the picture’s far from clear. Jane Williams of California Communities Against Toxics draws a chilling parallel to post-9/11 New York, where thousands of first responders later faced cancer and other illnesses from toxic exposure. With the Biden-Harris administration recently lowering the EPA’s lead dust threshold in 2024—underscoring there’s no “safe” level of lead—the stakes feel higher than ever.
What’s striking is the uncertainty. Oelsen’s awaiting more results, and oceanographers like Craig Nelson from the University of Hawaii point to a gaping lack of regulation and research on these pyrogenic materials. Meanwhile, the LA County Department of Public Health has advised avoiding water and debris along an 8-mile stretch of coastline. It’s a messy, evolving situation—one that demands both caution and curiosity.
On the flip side, there’s a tool giving us hope: global information systems, specifically geographic information systems (GIS). These systems crunch data—think vegetation, terrain, fire history, and weather patterns—to map out fire risks with precision. Case in point: CalFire’s newly released 2025 fire hazard severity zone maps, finalized for Southern California on March 24, 2025 (KTLA).
These maps classify areas into moderate, high, or very high hazard zones, covering an additional 1.4 million acres statewide. They’re already shaping building codes, defensible space rules, and emergency planning for 3.7 million Californians. Built on a science-driven model updated after over a decade, they reflect how climate change is dialing up fire risks. The Los Angeles Times reported that Northern California alone saw 377,000 acres added to regulated zones earlier this year. It’s a big step toward prevention—and one that could indirectly cut down on the toxic fallout we’re seeing now.
Here’s where it connects: reducing fire frequency and severity through GIS-driven maps like CalFire’s could limit the spread of contaminants in the first place. Fewer burned structures mean less asbestos, lead, and lithium ash washing into our beaches and lungs. But the maps aren’t a silver bullet for cleanup. They excel at prevention, not at guiding the messy work of managing what’s left behind. That’s where we need a dual approach—pairing cutting-edge tech like GIS with robust, science-backed response plans.
The evidence suggests these maps will lower future fire risks, and that’s no small win. But as the LA fires show, the disaster doesn’t end when the flames do. Research into contaminants is still catching up, and policy hurdles—like the Trump administration’s proposed cuts to the EPA’s science arm—could slow us down.
Looking Ahead……
This is a tale of two challenges: the immediate threat of what’s left in the ashes and the long game of stopping fires before they start. The Capital & Main piece opened my eyes to the health stakes, while CalFire’s maps remind us that technology can tilt the odds in our favor. At JonathanPortney.com, I’ll keep digging into these intersections of science, policy, and the world we live in. What do you think—how do we balance the here-and-now with the what’s-next? Drop your thoughts below—I’m listening.
Sources:
- “The Disaster After the Disaster: Many Contaminants May Be Overlooked in the Wake of the L.A. Fires,” Capital & Main, March 25, 2025
- “CalFire releases new fire hazard map for 2025,” KTLA, March 24, 2025