PFAS: The Forever Chemical That Kills
PFAS 'forever chemicals' constantly cycle through ground, air and water. By the 1960s, animal studies conducted by 3M and DuPont revealed that PFAS chemicals could pose health risks. But the companies kept the studies secret from their employees and the public for decades ...
What are PFAS?
"PFAS (per- and polyfluoroalkyl substances) are a class of chemicals that companies add to a wide variety of consumer products to make them non-stick, waterproof, and stain-resistant. There are currently more than 4,700 different PFAS chemicals on the market, making them among the most ubiquitous synthetic chemicals in the world" (PFAS Exchange)
How am I exposed to PFAS?
Unfortunately, there are many ways to become exposed to PFAS chemicals, most notably through the air you breath and the water you drink. Living close by a plant that PFAS produced plant is certainly cause to assume you may have been exposed to these contaminants. See the "Get PFAS Blood Test Tab" for more information on assessing your level of exposure.
Water consumption can be a significant source of PFAS among exposed populations. To help protect human health, the U.S. Environmental Protection Agency (EPA) recommends PFOA and PFOS levels in drinking water should not exceed 70 parts per trillion (ppt)6 . PFAS levels in drinking water have been found to vary significantly, depending on the geographic area and water treatment processes7 . For example, drinking water samples (N = 36,149) across the United States contained PFOS and PFOA levels ranging from below detection to 101–349 ppt for PFOA and 201–1,800 ppt for PFOS, with detectable levels in 33 states" (Batelle)
What products contain PFAS?
"PFAS are present in a multitude of products across a variety of industries, including nonstick Teflon™ cookware coatings, water-, grease-, and stain-repellents and fire-retardants for clothing, as well as textiles, carpeting, and lining paper products, such as takeout containers. 3M was one of the first companies to use PFAS in their products. In fact, Perfluorooctanesulfonic acid (PFOS) was the primary ingredient in Scotchgard™ fabric and carpet treatment, which is one of 3M’s most popular products" (http://nsglc.olemiss.edu/)
Why PFAS Last Forever:
"PFAS were only identified as chemicals of emerging concern in the early 2000s, when improving analytical methods were able to detect PFAS at lower concentrations than ever before in the environment. These methods also established that these chemicals were not going anywhere. This is because the carbon-fluorine bond, which comprises the chain of the PFAS, is one of the strongest bonds in organic chemistry, which makes the chemical very stable and difficult to break down. Their incredible stability has led to concerns regarding bioaccumulation and biomagnification, earning them the nickname 'forever chemicals'" (http://nsglc.olemiss.edu/).
The Difficulty of Interpreting Exposure
"Interpreting toxicological effects of PFAS is especially difficult due to the sheer number of PFAS in existence. Strategies such as read-across, whereby toxicological effects from one substance can be inferred to be similar to other substances with the same chemical structure and functional groups, can be used to develop toxicological information for PFAS which are lacking data. Common health effects from PFAS exposure include changes in birth weight, decreased fertility, decreased vaccination response and, in the case of PFOA, testicular and kidney cancer. PFAS also have the potential to bioaccumulate in plants and animals, and studies have shown that these exposures are not isolated to specific regions or geographic areas. Instead, they occur worldwide. There are currently no federal regulations under the Safe Drinking Water Act for PFAS, however the Environmental Protection Agency (EPA) has issued a lifetime health advisory of 15 parts per trillion for both PFOS and PFOA. Regulatory determinations are currently underway for establishing maximum contaminant levels for PFOS and PFOA in drinking water. As information regarding the toxicity of PFAS became more widely available, concern regarding the presence of PFAS in drinking water has grown (http://nsglc.olemiss.edu/).
The Harmful Effects of PFAS
Kidney cancer, testicular cancer, breast cancer, liver damage, ulcerative colitis, thyroid disease, endocrine disorders, low sperm count and mobility, fertility issues and developmental effects affecting unborn children are just some of the harmful effects of PFAS.
"Biomarkers of Exposure Understanding exposures to harmful chemicals and relationships between exposures and health effects is often best accomplished using biomarkers. The most widely used biomarker of PFAS exposure in humans is serum or whole-blood PFAS concentration2 . It is noteworthy that correlations may differ across moieties. Potential non-invasive biomonitoring samples such as urine, hair, and nails have shown varied reliability and validity across exposure levels and PFAS compounds16. Health Outcomes Considerable epidemiological research has been conducted to understand the possible adverse health effects of PFAS in humans, ranging from adverse biological function to frank disease. These studies have focused on highly exposed communities, workers at PFAS production or use facilities, and the general population. Most of these studies have focused on PFOS and PFOA, and a few other PFAS, investigating blood PFAS levels in the selected population in relation to adverse health endpoints. The health effects most commonly studied and reported are immunological, developmental or reproductive, hepatic, hormonal, and to a lesser extent, carcinogenic. Immunological Effects Investigations of immune system responses related to PFAS exposure have included asthma, allergic disorders, ulcerative colitis, infectious diseases, vaccine response, and autoimmune disorders. Of these outcomes, evidence suggests PFAS reduces vaccine efficacy in children, decreasing antibody production. However, this association may vary based on vaccine type, and is less clearly understood among adults compared to children. Other associations between PFAS exposure and immunosuppression are also evident, particularly for PFOA and PFOS. A few studies suggest PFOA may be related to increased risk of ulcerative colitis, an autoimmune disease that causes inflammation in the colon, and asthma2 . The evidence for other immunological health effects such as allergies is mixed, requiring further research18,19. Developmental and Reproductive Effects Studies examining fetal exposure and health outcomes, including rate of growth, obesogenicity, and neurodevelopment, have had mixed results, while studies of birth weight suggest a small reduction in birth weight associated with elevated PFAS10. Decreased fertility has also been linked to elevated serum PFOA and PFOS levels" (Battelle).
"Hepatic Effects Multiple reports summarizing current PFAS knowledge indicate a possible relationship between PFOA, PFOS, perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDeA), and increased total and LDL cholesterol2,10,19. There may be a biphasic dose-response-curve for PFAS and total cholesterol. Specifically, lower levels of PFOA were associated with higher increases in total cholesterol levels, suggesting changes in effect based on dose/serum level2 . Research also suggests an inverse relationship between elevated serum PFAS and reduced HDL18. Similarly, while there is conflicting evidence for an association between PFOS and triglyceride levels2,19, an overall pattern of positive association is emerging18,19. Endocrine Disruption Recent research has increasingly identified PFAS compounds as endocrine disruptors. Increased PFOA serum levels have been linked to an increased risk of thyroid disease, but this association was not found when examining perfluorohexanesulfonic acid (PFHxS), PFNA, or PFDeA2. A few additional studies have explored perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA) and found positive associations with thyroid disease18. Thyroid stimulating hormones, when disrupted, may result in frank disease outcomes such as Graves’ disease or benign pituitary tumors. In addition to disease, there are other reproducible adverse health effects associated with pre-clinical changes in thyroid function. For example, serum PFAS is likely associated with altered thyroid hormones20,21,22. Research has also examined relationships between PFAS and metabolic function, uric acid levels or hypertension, and insulin function. However, this research is limited, and additional studies are needed to understand the impact of PFAS on these endocrine and metabolic endpoints2,19. Cancer Studies have explored the association between PFAS blood levels and increased risk for numerous types of cancer, including colorectal, prostate, ovarian, melanoma, pancreatic, bladder, kidney, lung, testicular, breast, colon, and liver cancer. While many of these studies have been inconclusive, and results rely on non-standardized exposure assessments, studies evaluating populations with increased exposure to PFOS and PFOA have found a greater risk for testicular and kidney cancer2 . However, research on cancer outcomes remains limited. The International Agency for Research on Cancer concluded that PFOA is possibly carcinogenic23, and the U.S. EPA determined that there is suggestive evidence of carcinogenic potential of PFOA and PFOS in humans24,25. Despite these findings, the Michigan Panel noted that “cancer may not be the most sensitive health outcome to guide regulations for the protection of public health" (Batelle).
