What We Know About PFAS and Your Health
You’ve probably heard about many of the contaminants we write about, such as lead, arsenic, pesticides. A little while ago, we introduced you to a family of chemicals that wasn’t on anyone’s radar: PFAS.
PFAS, or per- or poly-fluoroalkyl substances, are man-made chemicals found in all sorts of products, like nonstick cookware, firefighting foam, and stain-resistant fabrics. If they’re everywhere, why are we only learning about their health threats now?
For a long time, the scientific community did not know PFAS had negative health effects–though evidence suggests that industry has known they are harmful. Now, we’re realizing that the potential health effects are startling. What’s worse, these water- and lipid-resistant compounds are extremely stable, meaning that they don’t break down in the environment at all. This makes them very hard to get rid of, and they’ve started building up in out bodies.
We introduced you to PFAS before, but now we’re going to delve deeper into exposure routes and potential negative health effects. We’re going to focus on two that have been making headlines because they have the most researchand are the focus of EPA's new "PFAS Action Plan": perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS).
But the fact is, there are thousands of PFAS compounds–including GenX. The health effects are likely similar across many of these different PFASs, leading advocates nationwide to call for regulation on the class of PFAS compounds as opposed to one contaminant at a time.
Where do I encounter PFAS?
Because they were manufactured so widely for so long, PFAS are all over the United States. Common exposure routes include drinking contaminated water, ingesting contaminated soil or dust, eating fish from contaminated water (especially water with PFOS), eating food that was packaged in material containing PFAS, and using products like nonstick cookware. The good news is that very little PFAS can cross the skin, so showering and bathing in contaminated water is a low-exposure risk.
Drinking contaminated water can expose you, though. If you suspect your water may be contaminated, or you have little ones that like to drink the bath water, you should definitely test your tap water. Researchers estimate that over 6 million Americans drink water with PFOA and PFOS levels higher than EPA's health advisory (70 parts per trillion). Given that there are thousands more PFAS that were not measured in this study – the risk is likely higher than scientists are able to quantify.
While we are exposed to PFAS daily, the most vulnerable people are the workers who make or process PFAS, most often by inhaling dust with PFAS. Those who live near fluorochemical plants are the also likely to have high exposure levels. Around these plants, water is often contaminated with PFAS, according to a 2018 CDC toxicology report.
Though the US has stopped production of PFOA and PFOS, other countries still use them in manufacturing. Those products can find their way to our homes, schools, and offices, increasing our potential exposure. What’s more, other compounds can break down into PFOA and PFOS, which then remain in the environment indefinitely.
What are the health effects?
At this point, we’re still learning. Scientists are doing research to determine the precise health effects of PFOA and PFOS. Regulatory bodies, too, are beginning to set guidelines for safe consumption. In 2016, the EPA established drinking water health advisories of 70 parts per trillion (or 0.07 µg/L) for concentrations of PFOS and PFOA, individually or combined.
Though we are beginning to regulate these substances, almost everyone in the United States has some level of PFAS in their blood. Unfortunately, our bodies don’t readily break down PFAS. That means that once PFAS are in your blood, they stay there for years. Studies are still ongoing, but the CDC compiled potential health effects from existing research to identify a suite of different potential effects on the body:
Hepatic (liver) effects:
Endocrine (hormonal) effects
The clearest impact of PFOS and PFOA is on pregnant women, as unborn children can be exposed to PFAS in utero. The CDC studies also show that liver appears to be a particularly sensitive target, as it is in charge of getting rid of a lot of toxins. Of great concern, PFAS is linked to obesity risk–with animal and epidemiological studies indicating that endocrine disruption from PFAS can affect weight gain and obesity for the people exposed and potentially across generations.
As we said, though, there’s still a lot we do not know. Many of these studies were performed on lab animals, focusing mostly on oral exposure, with some inhalation studies. These are useful and scientists can make assumptions about how animal studies relate to human vulnerability, but humans likely respond to PFAS differently than lab rats. Thus some pathways between PFAS and health outcomes remain unknown.
Epidemiological studies help us identify links between PFAS exposure and population-scale health outcomes. Such studies estimate PFAS exposures in different populations and track associated health effects–though correlation is not causation, the findings of these studies suggest several potential health impacts (listed above) that merit deeper investigation.
What we’re learning
As PFAS get more attention, scientists and government agencies are trying to learn more about how to detect and remove PFAS. PFOS and PFOA are highly soluble in water, so they are hard to remove by normal methods. The EPA, however, is working on new methods to detect and remove these chemicals from water.
Only in 2018 did new, advanced methods for PFAS detection just get announced by EPA. These methods – EPA 537 v1.1– reflect progress on PFAS detection because they can test for up to 18 types of PFAS. Tap Score tests for PFAS use this approach. Newer approaches, however, are under development to capture the full range of potential PFAS in drinking water–including the Total Oxidative Potential assays to measure precursor compounds to PFAS.
As far as removal goes, the EPA has been researching three main methods for removal. One method is using activated carbon, a porous organic material often used for removing organic compounds from water. Another method is ion exchange treatment, which uses positively-charged compounds to attract the negatively-charged fluorine ions on PFOS and PFOA. The third is called high-pressure membranes, which includes techniques like nanofiltration and reverse osmosis. These membranes could filter out PFAS — and other chemicals — from water.
If you test your water and it comes up positive for PFAS, you can employ these EPA-researched treatments in your home at point of entry (where water enters your home) or point of use (e.g. faucets). Do not try at-home remedies for treatment. For example, boiling your water can actually concentrate PFAS.
We are just beginning to understand the extent of the health effects, so your best bet is limiting your exposure. At home, this includes avoiding non-stick cooking products, avoiding packaged food, and carefully checking labels on a variety of products.
Test before you treat
In summary, nearly everyone is exposed to some level of PFAS, but how much depends on your location. From a water perspective, we advocate testing your water before taking any action!