How Do You Like Your Eggs? PFAS-Free, Please.
If you are an adult living in the United States, you have probably heard something about per- and polyfluoroalkyl substances, better known as PFAS. What I think many people still do not appreciate is just how widespread these chemicals have become, likewise how difficult some of them are for both the environment and our bodies to get rid of.
PFAS are not one chemical. They are an enormous family of synthetic fluorinated compounds that have been used because they can confer some remarkably useful properties: resistance to oil, grease, stains, water, and heat. These properties have made PFAS useful in everything from industrial manufacturing and firefighting foams, to waterproof clothing, food packaging, stain-resistant materials, and certain nonstick applications.
They are incredibly useful, but unfortunately some of the same chemistry that makes them work so well also makes them remarkably persistent. For example, two of the best studied PFAS are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). Estimates vary, but a systematic review found human elimination half-lives generally ranging from about 1.5 to 5.1 years for PFOA and 3.4 to 5.7 years for PFOS.¹
Yes, you read correctly. Years!
That means exposure today does not necessarily become yesterday's problem tomorrow. And this is not some rare exposure confined to people working in a fluorochemical factory. In a Johns Hopkins study performed in Baltimore, researchers analyzed umbilical-cord serum from 299 newborns. PFOA was detected in 100% of the samples and PFOS in 99%.² These were newborn babies. They had never eaten fast food out of a grease-resistant wrapper, bought waterproof clothing, cooked breakfast in a nonstick skillet, or made a decision about what water filtration system to install in their kitchen. They were exposed before they ever took their first breath. That fact alone doesn't prove that those concentrations caused harm. It does, however, demonstrate how successfully these manufactured chemicals have worked their way into our environment and subsequently into us. And that brings us to the questions that actually matter:
What do these chemicals do to our bodies?
How much is harmful?
What don't we know yet?
What can we reasonably do about it?
The Part That Concerns Me Most Is What We Don't Know
Bad news first.
When you start digging through the PFAS literature, you very quickly realize that certainty is difficult to come by. We have animal studies. We have cellular studies. We have mechanistic research. We increasingly have large epidemiological studies looking at PFAS concentrations in humans and associations with different diseases. What we generally do not have are controlled experiments exposing human beings to PFAS and then waiting decades to see what happens (for obvious ethical reasons). That means much of the human literature is observational.
Observational science is important, but association does not automatically equal causation. People with higher PFAS levels may differ from people with lower levels in ways researchers cannot perfectly measure. Different PFAS behave differently. Exposure often occurs as mixtures. And the biology of PFAS metabolism can differ considerably between laboratory animals and human beings. We should be appropriately humble about those limitations. But humility works in both directions.
We should not claim causality where causality does not exist. We should also not claim safety where safety is not explicitly demonstrated.
There are thousands of compounds that fall under broad definitions of PFAS, yet meaningful human epidemiological research exists for only a small fraction of them. Sadly, we know considerably more about legacy compounds such as PFOA and PFOS than we do about many of the compounds that have followed them. And even within the better-studied PFAS, the evidence is not perfectly uniform. Still, epidemiological and toxicological research has raised concerns involving lipid metabolism, immune function, liver function, fetal growth and development, reproductive outcomes, blood pressure, and certain cancers.3
One particularly interesting signal involves the immune system. A systematic review and meta-analysis examining vaccine responses found associations between increasing concentrations of several PFAS, particularly PFOA, PFOS, and PFHxS, and lower antibody concentrations following certain vaccinations, with some of the stronger findings occurring in children.4
There is cancer concern as well. In 2023, the International Agency for Research on Cancer evaluated the available evidence and classified PFOA as carcinogenic to humans and PFOS as possibly carcinogenic to humans.5
That does not mean having PFOA in your blood means you are going to develop cancer. If that were the case, majority, if not nearly everyone in the US would suffer this fate based on the aforementioned epidemiological data.
Fortunately, it doesn't work that way. Cancer, cardiovascular disease, metabolic disease, neurodegenerative disease, and most chronic illnesses develop through complicated interactions between genetics, age, behavior, environment, and innumerable biological events over years or decades. No one gets to look backward at age 75 and identify every molecule that tipped the scale one direction or another. But that is also why I think environmental exposures deserves some attention. Our inability to precisely quantify an individual's future harm is clear reason for me to take these things as seriously as reasonably possible.
There Is Another Reason These Chemicals Make Me Uncomfortable
There is something biologically interesting about PFAS. Many PFAS are poorly metabolized or not appreciably biotransformed at all in humans. Instead of being readily broken apart by our normal metabolic machinery, their elimination can depend on processes such as biliary and urinary excretion. Certain PFAS bind strongly to proteins, and kidney transport systems can actually reabsorb some of these molecules after they have been filtered, helping contribute to their prolonged residence in the body.6
Our physiology has not historically encountered these particular manufactured molecules over long periods of time. That fact by itself does not establish toxicity, but when you combine novel chemistry with biological persistence, widespread exposure, observed health associations, and large gaps in long-term human data, I think prudence becomes a very reasonable response.
Put more simply:
If a chemical stays in my body for years, has evidence suggesting potential biological harm, and we still have substantial uncertainty about its long-term effects, I would rather have less of it in me than more.
GenX Made This Much Less Theoretical for Me
I am particularly familiar with this issue because I live in the Wilmington, North Carolina area. For years, PFAS containing wastewater from fluorochemical manufacturing upstream entered the Cape Fear River, the primary drinking-water source for much of our region. One compound that became almost synonymous locally with the problem was hexafluoropropylene oxide dimer acid HFPO-DA, commonly referred to by the trade name GenX.
GenX was introduced in part as an alternative to older PFAS chemistry such as PFOA. This is where the story becomes frustrating. A newer chemical may have advantages over the chemical it replaces. GenX, for example, appears to remain in human blood for much less time than PFOA. But shorter persistence does not automatically mean biologically harmless. Animal studies involving GenX have continued to demonstrate biological effects, particularly involving the liver and lipid and bile-acid metabolism.7 Human outcome data remain far less developed.
Even more interestingly, when researchers actually examined the blood of Wilmington residents in the GenX Exposure Study, GenX itself was not detected above the study's reporting limit. What they did find were several other previously poorly understood fluoroethers associated with the Cape Fear River contamination. Three of those compounds were detected in more than 85% of participants, while legacy PFAS such as PFOA, PFOS, PFNA, and PFHxS were found in nearly everyone studied.8 That finding captures the problem exceptionally well. We tend to talk about "GenX" or "PFOA" as though we are confronting one molecule at a time. We aren’t. We are dealing with a continually evolving family of chemicals, many of which have considerably less human health data than the compounds they replaced.
In a later analysis of New Hanover County residents, the duration of drinking-water exposure was associated with higher serum concentrations of all seven PFAS examined. People drinking municipal water that had undergone additional home filtration, or drinking nonmunicipal water, generally had lower PFAS concentrations than those drinking municipal water without additional filtration.9
That gets my attention because these aren't hypothetical people in an environmental-health textbook. These are people living where my family lives!
The Good News
There actually is good news.
Human concentrations of several legacy PFAS have fallen significantly in the United States as manufacturing practices and exposures have changed.¹0 That is encouraging for a very important reason:
Exposure is modifiable.
This is not a story in which the conclusion has to be, "PFAS are everywhere, therefore there is nothing we can do.” Nor do I think there is capability to achieve some impossible state of environmental purity. I genuinely hate the avoidance game when it comes to health. Once you start looking, you can find something potentially concerning everywhere: PFAS, microplastics, pesticides, heavy metals, air pollution, endocrine-active compounds, food-contact chemicals, and the list goes on. Without ballast, sobermindedness, environmental health becomes environmental anxiety. I have no interest in living that way, and I certainly don't want to encourage other people to live that way. Very simply:
Reduce unnecessary exposure.
Take this health category seriously, but within reason. If I can remove an unnecessary variable from my family's long-term health equation without creating ten other problems, why wouldn't I?
Start With the Water
For many people, drinking water is a very meaningful place to start. This is particularly true if you live in an area with known PFAS contamination. Granular activated carbon, or GAC, can remove many PFAS from water through adsorption onto an enormous porous surface area. Reverse osmosis (RO) is another effective technology and can remove a wide variety of PFAS.
Performance varies depending upon the PFAS involved, the filter design, the water chemistry, the age of the filter, flow rates, and maintenance. Short-chain PFAS can be particularly difficult for some activated-carbon systems. A recent review of point-of-use filtration emphasized that real-world performance is variable and that inadequately maintained filters may lose substantial effectiveness.¹1 We installed a reverse-osmosis system years ago in our own home. In theory, wonderful. In reality, we have four kids and a long list of things competing for our attention. There have absolutely been periods where those filters stayed in the system longer than they should have. That illustrates something I talk about frequently in health:
The system matters more than the intention.
You can be an incredibly motivated person. You can deeply care about your family's health. You can read every paper in PubMed. But you still only have so much attention to expend every day.
So automate as much as possible.
Put the replacement filters on subscription.
Put the filter change on the calendar.
Keep the replacement cartridge where you can actually find it.
Build systems so that doing the healthier thing becomes easier than forgetting it. I hope one can see how that principle matters far beyond PFAS.
What About the Nonstick Pan?
This brings us back to the egg. Nonstick cookware is probably the PFAS-related product most people immediately recognize. Historically, PFAS such as PFOA have been involved in fluoropolymer manufacturing, and PFAS have been identified in various food-contact materials. PFAS-containing or fluorinated grease-resistant materials have also been used in food wrappers, microwave-popcorn bags, paper products, and other packaging, with evidence that some compounds can migrate from food-contact materials into food.¹2 I want to be measured here. Your modern nonstick skillet is not necessarily the largest PFAS exposure in your life, and I don't think the evidence justifies telling someone to panic and throw every nonstick pan in the trash tonight. But cookware is an exposure choice over which I have almost complete control. So personally, I see little downside to removing the variable. We primarily use stainless steel and cast iron.
Cast iron is cheap, practically indestructible, and with a little cooking oil works incredibly well. Stainless steel is similarly durable and versatile. You buy these things once and they can last decades. A little extra-virgin olive oil, avocado oil, butter, or whatever cooking fat fits what you are making, and your eggs will survive.
We switched years ago, and it wasn’t particularly difficult or expensive. Surprisingly, I’m quite impressed with the quality of food I can produce using some of our stainless and cast iron utensils. In my opinion, they far outperform the previous non-stick items they replaced in many applications.
Then Look at the Easy Consumer Choices
PFAS have been used wherever manufacturers needed water, grease, oil, or stain resistance. That has historically included some:
waterproof or water-resistant clothing;
stain-resistant carpets and furniture;
food packaging;
cosmetics and personal-care products;
cleaning and surface treatments;
outdoor equipment;
and numerous industrial and specialty products.
One particularly important labeling trap is assuming "PFOA-free" or "PFOS-free" means “PFAS-free." It likely doesn’t. It simply means that those particular legacy compounds were not used. Marketing can be very deceptive. Maintain a wary eye. When practical, I prefer products whose manufacturer specifically states that they are made without intentionally added PFAS or fluorinated treatments. In the western hemisphere there is generally good alternatives that one can find that will be explicitly PFAS free. Sometimes this takes a little homework, but it isn’t impossible.
Can We Get PFAS Out Once They're Already in Us?
This is another fascinating part of the biology. Women, particularly menstruating women, have often been observed to have lower serum concentrations of some long-chain PFAS than men. Pharmacokinetic modeling suggests that menstrual blood loss is one route of elimination, although pregnancy, placental transfer, breastfeeding, and other sex-related differences also contribute.¹3 This leads to the obvious male solution: Bloodletting… That’s a joke. Please do not intentionally bleed yourself to remove PFAS.
Interestingly though, someone essentially did study it. A randomized clinical trial involving Australian firefighters with elevated PFAS exposure compared plasma donation, whole-blood donation, and observation. Both donation strategies reduced serum PFAS concentrations compared with observation, with plasma donation producing the larger reductions for the primary PFAS studied.¹4
Prudence, Not Panic
I think environmental-health is actually really important and should be taken seriously, but within reason. Not panic driven, but measured prudence.
What if the intervention is switching from one frying pan to another? What if it is installing an appropriate water filter when you already know your drinking-water source has PFAS? What if it is choosing the jacket without intentionally added PFAS when both jackets are sitting beside one another on the rack? I don't need proof that choosing the second jacket will extend my life by 13.6 days. I simply need enough evidence to conclude that one choice plausibly removes an unnecessary exposure at reasonable cost or effort. The way I think about this is essentially an exercise in uncertainty.
Imagine two otherwise identical paths.
On one path, I maintain unnecessary chronic exposure to a persistent chemical associated with adverse biological effects and for which large gaps in long-term data remain. On the other path, I reasonably reduce that exposure without materially harming my quality of life. I know which path I would rather take. That doesn't mean the first path guarantees disease. It doesn't mean the second path guarantees health. It means I am reducing uncertainty where I reasonably can. That is prudence.
Play the Long Game
You will probably never know whether buying the stainless-steel skillet mattered. You will never meet the 75-year-old version of yourself who drank different water, slept an hour less every night, exercised three days less each week, ate differently, or accumulated a slightly different set of environmental exposures. That alternate person doesn't exist for comparison. Preventive health is frustrating that way. The consequences of today's decisions often occur years or decades later, and we almost never get to see the counterfactual. That reality can breed complacency, but I think it should do the opposite.
Our food, water, air, movement, sleep, relationships, metabolic health, and environmental exposures interact with our biology repeatedly, day after day, for decades. Some variables matter enormously. Others might matter very little. Our responsibility is to identify the important ones as best we can, remove unnecessary risk where practical, build systems that make good decisions easier, and then get on with living.
And yes, if I can cook my eggs in cast iron, drink appropriately filtered water, be a little more selective about the products my family repeatedly uses, and decrease our long-term exposure…. I’ll take them eggs PFAS-free, please.
References
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Apelberg BJ, Goldman LR, Calafat AM, et al. Determinants of fetal exposure to polyfluoroalkyl compounds in Baltimore, Maryland. Environmental Science & Technology. 2007;41(11):3891-3897. doi:10.1021/es0700911.
Xing WY, Sun JN, Liu FH, et al. Per- and polyfluoroalkyl substances and human health outcomes: an umbrella review of systematic reviews with meta-analyses of observational studies. Journal of Hazardous Materials. 2024;472:134556. doi:10.1016/j.jhazmat.2024.134556.
Crawford L, Halperin SA, Dzierlenga MW, et al. Systematic review and meta-analysis of epidemiologic data on vaccine response in relation to exposure to five principal perfluoroalkyl substances. Environment International. 2023;172:107734. doi:10.1016/j.envint.2023.107734.
Zahm S, Bonde JP, Chiu WA, et al. Carcinogenicity of perfluorooctanoic acid and perfluorooctanesulfonic acid. The Lancet Oncology. 2024;25(1):16-17. doi:10.1016/S1470-2045(23)00622-8.
Niu S, Cao Y, Chen R, et al. A state-of-the-science review of interactions of per- and polyfluoroalkyl substances (PFAS) with renal transporters in health and disease: implications for population variability in PFAS toxicokinetics. Environmental Health Perspectives. 2023;131(7):076002. doi:10.1289/EHP11885.
Yoo HJ, et al. Perfluorooctanoic acid (PFOA) and hexafluoropropylene oxide-dimer acid (GenX): hepatic stress and bile acid metabolism with different pathways. Ecotoxicology and Environmental Safety. 2023;258:115001. doi:10.1016/j.ecoenv.2023.115001.
Kotlarz N, McCord J, Collier D, et al. Measurement of novel, drinking water-associated PFAS in blood from adults and children in Wilmington, North Carolina. Environmental Health Perspectives. 2020;128(7):077005. doi:10.1289/EHP6837.
Cuffney M, Wilkie AA, Kotlarz N, et al. Factors associated with per- and polyfluoroalkyl substances (PFAS) serum concentrations in residents of New Hanover County, North Carolina: the GenX Exposure Study. Environmental Research. 2023;237(Pt 2):117020. doi:10.1016/j.envres.2023.117020.
Botelho JC, et al. Per- and polyfluoroalkyl substances (PFAS) exposure in the U.S. population: NHANES 1999-March 2020. Environmental Research. 2025;120916. doi:10.1016/j.envres.2025.120916.
MacKeown H, Magi E, Di Carro M, Benedetti B. Removal of perfluoroalkyl and polyfluoroalkyl substances from tap water by means of point-of-use treatment: a review. Science of the Total Environment. 2024;954:176764. doi:10.1016/j.scitotenv.2024.176764.
Ramírez Carnero A, Lestido-Cardama A, Vazquez Loureiro P, Barbosa-Pereira L, Rodríguez Bernaldo de Quirós A, Sendón R. Presence of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in food contact materials and its migration to food. Foods. 2021;10(7):1443. doi:10.3390/foods10071443.
Gomis MI, Vestergren R, MacLeod M, Mueller JF, Cousins IT. Historical human exposure to perfluoroalkyl acids in the United States and Australia reconstructed from biomonitoring data using population-based pharmacokinetic modelling. Environment International. 2017;108:92-102. doi:10.1016/j.envint.2017.08.002.
Gasiorowski RE, Forbes MK, Silver G, et al. Effect of plasma and blood donations on levels of perfluoroalkyl and polyfluoroalkyl substances in firefighters in Australia: a randomized clinical trial. JAMA Network Open. 2022;5(4). doi:10.1001/jamanetworkopen.2022.6257.
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