What You Should Know About the PFAS in Your Food
Can we keep these forever chemicals out of our diets?
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When asked about the relative risks of per- and polyfluoroalkyl substances (PFAS) exposure, Graham Peaslee recalls the story of an Australian firefighter who was being studied by a colleague.
“She got funding to do a blood study of 700 firefighters in South Australia,” Peaslee, an Emeritus professor at the University of Notre Dame, says. “She measured the PFAS in all of them, and she found that they were elevated relative to the general population, about 10–12 parts per billion instead of 5 [parts per billion]. And it was expected, because they [the firefighters] use AFFF [aqueous film-forming foam].”
AFFF is an expansive artificial foam used to extinguish fires. It’s become notorious in recent years for its high concentrations of PFAS.
“There are some firefighters with less than average PFAS, below 5,” Peaslee continues. “There were some averaging around 12. But the highest one was around 1,700. And he was more than double the next, which was around 700. So that one firefighter got a special visit.”
“She went out to visit him – he was in the suburb of Adelaide – and said, ‘What are you doing? Are you drinking the AFFF?’ And, no, indeed he’d never actually used AFFF. So why was he getting exposed? And this is an interesting story because it turned out he was a bodybuilder.”
“This was a residential fire station,” Peaslee explains, “where they lived for a week on base. [The fire department] made all the suburban fire stations have a professional gym, and they got a professional kitchen installed and lessons on how to cook. The firefighters responded to this very positively; they were in better shape, they ate better. And this one firefighter with 1,700 parts per billion in his blood was eating 5 organic egg yolks a day as part of his protein-building diet. Well, egg yolks are highly bio-accumulative. He got five fresh organic eggs a day because the station kept a bunch of chickens out the back. And they fed them the fresh organic wheat that they grew right in the backyard, which happened to be around an old test pit where they tested the foam…”
“So, the foam from 20 years ago, which he had never touched, was leaching into the wheat, which was being fed to the chickens, which accumulated [the PFAS] in their eggs. This guy ate five eggs a day and his PFAS was through the roof!”
While this story may seem specific to Adelaide firefighters, Peaslee says it teaches a broader lesson on PFAS exposure: what matters is location, location, location.
Concerned about the PFAS potential of those crab claws? It matters where those crustaceans were caught. Worried about the safety of your tap water? It matters what level of PFAS pollution is upstream, according to Peaslee.
But how is the average consumer meant to know the relative levels of PFAS contamination in their local area or, indeed, the area where their food is sourced? Well, that’s one of the many PFAS challenges to address, says Peaslee. Fortunately, the US Environmental Protection Agency (EPA) has just taken the first step.
PFAS and the EPA
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PFAS are a growing concern around the world. These substances were first mass-produced in the mid-20th century to waterproof consumer products like pans, paints and packaging. They’re now known as “forever chemicals” because they have an almost unbreakable highly fluorinated alkyl chain backbone that makes them extremely chemically stable and difficult to degrade naturally.
This hardiness is all the more troubling considering the recent wave of research linking the chemicals to cancers, high cholesterol and low birth weights.1-3 Avoiding the chemicals doesn’t seem to be an option, either; most Americans already have some levels of PFAS in their blood, according to the US Department of Health and Human Services.
To keep a closer eye on the rising contamination issue, the Biden Administration announced in April that it had finalized strict limits on six types of PFAS in drinking water – the first national limits of their kind in the US. Two common types of PFAS (PFOA and PFOS) now cannot exceed 4 parts per trillion in public drinking water, while 3 other PFAS chemicals (PFNA, GenX chemicals and PFHxS) are restricted to 10 parts per trillion.
The move was welcomed by many PFAS researchers, but few would say it was mission accomplished.
“It was nice to see the EPA take this kind of hazard index approach, but I have two minds about it,” says Megan Romano, an associate professor of epidemiology at the Geisel School of Medicine at Dartmouth. “Because regulating six [chemicals] together was a big step for the EPA; they’ve always gone chemical by chemical. But when we’re talking about a class of chemicals where there’s 12,000 or 15,000 depending on whose definition, 6 is a drop in the bucket.”
To fill that PFAS bucket up and make some real change, Romano says action will be needed to prevent PFAS from entering waterways and food systems in the first place.
“Once the PFAS get into the food chain, I think they’re going to end up in a lot of places,” she says.
“It’s really the upshot, unfortunately. So I think the key focus, from my perspective, is that we need to do more to keep it out of the food chain.”
Such further enforcement could take some time, however, if certain state PFAS policies are anything to go by…
The impact of state-level PFAS regulation
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“I went to a committee hearing at the State House of Representatives [in Indiana],” recalls Peaslee. “They’re considering a bill to relabel what is a PFAS in the state of Indiana. And I was shocked because, ‘What do you mean it's not a PFAS?’ There’s a scientific definition; this is a PFAS and that isn’t. Well, they wanted exemptions. ‘Polymers shouldn’t be called PFAS because they were different; they’re friendly PFAS’, etc.”
“It was just a couple guys in the economic community who said, ‘Look, we don't want to stifle our businesses. We want more jobs.’”
“I was surprised because I thought people would listen to arguments, and some did,” Peaslee says. “But the majority did not in that case. And that’s an example where the first state in the United States has redefined what a PFAS is to not include polymers or liquids or gases. A liquid PFAS is not a PFAS anymore. That’s a little frightening.”
Of course, Indiana’s trajectory is just one way that PFAS regulation can go. California, in contrast, has prohibited the sale of food packaging containing PFAS since 2023.
This geographic variation is befitting of the PFAS problem, according to Peaslee. Remember, it’s all about location, location, location.
“There was an FDA study, just to convince everybody they’re doing their job,” Peaslee says. “They went out and measured 500 food products – raisins and fresh fruits and vegetables and fish [etc.]. And what they found was only 4 or 5 really had PFAS in them, which meant that the food supply is safe in the United States. I mean, 93% don't have any PFAS. It really depends on where you are.”
“It really is too limited a study to make much of,” he admits. Nonetheless, given his own PFAS research and the work of others, he retains “the general theory that, in most places, the food isn’t contaminated. But there will be places where it is.”
One such place is off the coast of New Hampshire.
Researchers advise caution with PFAS dietary advice
Simple and Efficient Analysis of PFAS in Milk, Eggs and Infant Formula
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Back in April, Megan Romano and her colleagues published new findings on how PFAS were affecting the food chain in the waters of New Hampshire.4 After analyzing local seafood, they found that lobster and shrimp contained high levels of these forever chemicals; averages ranged as high as 1.74 and 3.30 nanograms per gram of flesh, respectively, for certain PFAS compounds.
The results were a little alarming but not unexpected, given the growing association with fish, aquaculture and PFAS. One study published in 2023 reported that PFAS were widely detected in freshwater fish across the US.5
Again, though, what likely matters more than food type is food location, and that’s a point that might be getting lost in the growing seafood paranoia, says Romano.
“It’s a little bit tricky, because we have spent more time testing seafood,” she says.
“I’d hate for seafood to get a bad rap because it was the first that we tested. We haven’t tested a really broad spectrum of food to understand where all those food-based sources might be.”
To reflect this caveat, Romano concluded her study by advising that New Hampshire consumers keep their whole diet varied.
“We do know from studies of the general population in the US that folks who eat more seafood, meat, chicken and dairy tend to have higher concentrations of PFAS in their blood,” she told Technology Networks at the time. “This really underscores the importance of eating a balanced diet that includes a wide variety of healthy foods so that, for example, no single protein source makes up too great a portion of your overall diet.”
What does this mean for PFAS in food?
The field of PFAS research is still in its infancy, but a few key points have already become salient. In low quantities, the chemicals are unavoidable. In high quantities, occupation and location are paramount risk factors. In the US, the EPA has begun efforts to track such hotspot locations but much more work will be needed to map the world’s kernels of PFAS pollution – and even more regulatory work will be needed to curb the production of the chemicals in the first place.
In the meantime, Romano’s dietary advice may be the most workable for avoiding ingesting high amounts of forever chemicals and risking the consequences that a certain Adelaide firefighter had to endure.
“That gentleman, he was healthy at the time they interviewed him,” Peaslee recalls, “but he went in for medical treatment to try and lower his PFAS levels. They put him on some blood thinners. Basically, he had to donate blood and throw it away every two weeks as often as he could stand it.”
About the interviewees
Graham Peaslee is a concurrent professor of chemistry and biochemistry and physics at the University of Notre Dame. He is also the co-founder and chief technology officer of UMP Analytical, a chemical testing company specializing in PFAS and connecting university equipment to business needs. Since 2019, he has been a fellow of the American Chemical Society.
Megan Romano is an associate professor of epidemiology at the Dartmouth Geisel School of Medicine. Her research and the work of her lab, the Romano Lab, primarily explores the effects of environmental endocrine disrupting chemicals exposure during the sensitive windows of pregnancy and gestation, on breastfeeding and early life growth.
References:
1. Li H, Hammarstrand S, Midberg B, Xu Y, Li Y, Olsson DS, Fletcher T, Jakobsson K, Andersson EM. Cancer incidence in a Swedish cohort with high exposure to perfluoroalkyl substances in drinking water. Environ Res. 2022. doi: 10.1016/j.envres.2021.
2. Liu B, Zhu L, Wang, M, Sun Q. Associations between Per- and Polyfluoroalkyl Substances Exposures and Blood Lipid Levels among Adults—A Meta-Analysis. Environ. Heal. Persp. 2023. doi: 10.1289/EHP11840
3. Kashino I, Sasaki S, Okada E, Matsuura H, Goudarzi H, Miyashita C, Okada E, Ito YM, Araki A, Kishi R. Prenatal exposure to 11 perfluoroalkyl substances and fetal growth: A large-scale, prospective birth cohort study. Environ. Intern. 2020. doi: 10.1016/j.envint.2019.105355
4. Crawford KA, Gallagher LG, Giffard NG, et al. Patterns of seafood consumption among New Hampshire residents suggest potential exposure to per‐ and polyfuoroalkyl substances. Expos. and Heal. 2024. doi: 10.1007/s12403-024-00640-w
5. Barbo N, Stoiber T, Naidenko OV, Andrews DQ. Locally caught freshwater fish across the United States are likely a significant source of exposure to PFOS and other perfluorinated compounds. Environ. Res. 2023. doi: 10.1016/j.envres.2022.115165
