This week’s rainstorms in Southern California resulted in debris flows and mudslides, especially in the areas near last month’s fires, but they also may have affected the spread of toxic elements released by the destruction.
It’s a possibility researchers from the University of Southern California are examining after they previously found elevated levels of lead in fire-ravaged areas.
Their initial findings pointed to high levels of the heavy metal near burn sites, which makes sense, given lead’s presence in older paints and some types of batteries that were destroyed by the fires.
But the high winds and other factors helped the lead-containing ash spread widely, and even if it wasn’t detected elsewhere in great quantities, any lead exposure is dangerous, as the Mayo Clinic explains.
“Even small amounts of lead can cause serious health problems,” with larger amounts possibly resulting in death,” according to the clinic.
Fortunately, much of the lead-containing ash was likely washed away in the recent rains, reducing one of the primary risks: inhaling toxic dust.
“[Airborne ash] is somewhat mitigated by the recent rains, which should at least help to keep too much of the ash from resuspending into the air, and it’s something that the cleanup crews are just going to have to be aware of as they seek to clear out all of that burned material from Altadena,” said Seth John, an associate professor of earth sciences. “They’ll have to be very careful when doing so, not to resuspend that ash back up into the air where people could be exposed to it.”
John pointed out that the rainfall can be a double-edged sword, reducing the airborne danger but picking up ash and its dangerous elements and compounds in rivulets of water and dispersing them widely and unpredictably.
“Some of that will get washed into the gutters and then go into the rivers and out into the ocean,” John said. “Some of it may sort of escape that and just be be contained in Altadena and presumably eventually be cleaned up during the remediation process.”
Josh West, a professor of earth sciences and environmental studies whose home was partially destroyed in the Palisades Fire, used his property as an example of how tricky that cleanup can be, pointing out that sandbags and other protective items near his home are trapping some of the ash, while other potentially hazardous fire detritus was moved onto other properties or even swept all the way to the Pacific Ocean.
This is where Los Angeles’ long history with pollution comes into play.
As West detailed, “there’s a long-term history of lead accumulation that has to do with all kinds of things, everything from leaded gasoline to leaded paints, a lot of industrial uses over many decades, and even though we phase many of those out, lead has accumulated in the environment.”
And after action last year by the federal government, the number of sites that are contaminated with lead likely rose a great deal. The EPA decided last year to lower the screening level for lead in soil from 400 parts per million to 200 ppm, meaning more locations are considered contaminated, even if they were considered safe only a couple of years ago.
When the lead-containing ash settles on those locations, its likely to further contaminate them, and serious action will be required to remediate those areas before they can be used safely again.
“It doesn’t just disappear,” said West. “So I would say we’re exposed to it all the time. I think what’s concerning is that it’s like many, many things…The cumulative effect over time matters,” meaning lead poisoning becomes more likely as more of the metal is encountered over a lifetime, instead of the primary risk factor being how much a person was exposed to at a single time.
So if someone’s lead-contaminated back yard is never remediated, the home’s residents could still be accumulating toxic lead in their bodies years later, and that could play a part in serious health issues.
“Lead persists for an extremely long amount of time,” agreed Sam Silva, assistant professor of earth sciences, civil and environmental engineering, and population and public health sciences. “If you do nothing about it, lead will stick around for quite some time. It doesn’t just go away like like some other compounds might. It doesn’t just blow away with the wind.”
The scientists are also worried about the possible contamination of the Pacific Ocean and, if the lead does make to the Pacific, what happens to it and how it affects the ecosystem. Further testing of both land and sea will be key to determining the risk posed to the public.
In the meantime, the scientists suggest the public follow a few tips for safety — they’re listed below — and remember that in the aftermath of fires like these, lead is just one of multiple possibly hazardous compounds.
Burned plastic, arsenic, other heavy metals and a variety of other substances could also be dangerous, so protecting yourself and your loved ones is of utmost importance.
“We tested for lead,” Silva explained. “There are loads of other potential contaminants that we just haven’t tested for yet … Lead is not the only potential contaminant that can come from fires, and so it’s still worth it to pay attention to what we hear from the state and local governments about what is and isn’t safe.”
How to protect yourself and your family
- When near burn areas and sites of possible airborne ash, wear personal protective equipment. LAist suggests the following:
- Tight-fitting N95 mask or P100 respirator
- Rubber gloves
- Long-sleeve shirt and pants
- Socks and shoes
- Eye protection
- Wet ash before you try to clean it up, as it can otherwise be disturbed and go airborne again
- If you grow your own fruits and vegetables, be sure to rinse it thoroughly before eating
- If your pet encounters ash, wipe its feet clean and give it a bath, if necessary
- Use an air purifier to help clean the interior of your home, where toxins could be trapped and unable to escape
