Where you live in LA can mean more ‘forever chemicals’ in your blood

There’s new evidence that your environment can play a significant role in how much you’re exposed to “forever chemicals,” a nickname for a group of harmful human-made substances that end up in your blood and are nearly impossible to get rid of.

University of Southern California researchers found in a study that some Angelenos, who lived near or too far from certain neighborhood factors, had a higher presence of chemicals in their bloodstream.

Why the study matters

Talk of “forever chemicals,” officially known as per- and polyfluoroalkyl substances (PFAS), is usually focused on our tap water supply. But these globally-used chemicals are in tons of consumer products, including grease-resistant food packaging, nonstick cookware, and waterproof clothing.

“You really need a more comprehensive way to deal with these chemicals because it’s not enough to give people clean water,” said Shiwen “Sherlock” Li, the study’s lead author and a postdoctoral researcher in the Keck School of Medicine’s Department of Population and Public Health Sciences.

The study worked with 446 Southern California residents, mostly in L.A. County, and looked at four major factors to see how they affected PFAS levels in their blood:

• Tap water
• Proximity to industrial polluters
• Proximity to Superfund sites (an EPA designation for certain toxic waste dump areas)
• Low access to fresh foods

Every factor was associated with a significant increase.

An illustration of government data that shows the distribution of detection of PFOA (a type of PFAS) in tap water, locations of Superfund sites and potential PFAS-polluting industrial sites.

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Courtesy Shiwen "Sherlock" Li

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Neighborhood low food access in different census tracts using data from the USDA Food Environment Atlas. One of the ways low access to food is defined is by 33% of the population living more than half mile from the nearest supermarket, supercenter, or large grocery store.

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Courtesy Shiwen "Sherlock" Li

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If the research participants lived in neighborhoods with contaminated drinking water, or lived far from a grocery store — meaning they’re likely more apt to eat packaged fast food — the increased ranged from 40% to 60%. Li said some types of PFAS even showed a more than 100% jump. Living within 3 miles of an industrial site that processes PFAS also showed higher blood levels.

Keep in mind, blood presence is measured in milliliters, and the baseline levels in the general population are very low. However, current research suggests even tiny volumes can contribute to adverse health effects.

Li works in environmental justice research and has long been interested in the neurotoxic effects of PFAS, including why they have greater effects on some people over others. While the study isn’t meant to show what areas in L.A. County have more PFAS, Li said it’s about how systemic factors can impact us.

“In my opinion, it’s harder to change individual behaviors,” Li said, “but if you can create clean environments for everyone, they don’t need any behavioral change in the first place.”

While the EPA is taking steps to remove PFAS chemicals in our water, Li hopes policymakers will use the study as evidence to support environmental cleaning efforts.

How PFAS can affect human health

Low-income neighborhoods especially already have water contamination and air pollution issues for other reasons, so linking it to PFAS potentially adds another reason for harsher health outcomes. For example, other studies have shown Southeast L.A. to have more contamination than other neighborhoods.

“If people are worried about lack of green space, lead issues, or water infrastructure issues, they should also consider PFAS,” Li said.

Dr. Lisa Patel, a clinical associate professor of pediatrics at Stanford Children's Health, said other studies have shown PFAS can raise your cholesterol, lower your antibody response to certain vaccines and increase risk for pregnancy-induced hypertension and preeclampsia.

“There are some small decreases in birth weight that have been noted from exposure to PFAS, and then there’s an increased risk of kidney and testicular cancer as well,” Patel said.

Patrick Allard, a professor in the Institute for Society and Genetics at UCLA, said PFAS chemicals have a “constellation” of other health effects, including a strong impact on the immune system. There are also questions about whether that could be linked to neurological disorders like ADHD.

“I mean, I could go on — cardiovascular effects, kidney defects,” he said. “It seems like you can make connections between PFAS and many kinds of health effects.”

Both experts echoed that while there’s been more research interest into PFAS, we still don’t have a good handle on how long it takes for these issues to play out because people are exposed in different durations, ways, and amounts.