PFAS (per- and polyfluoroalkyl substances), the non-degrading “forever chemicals,” are again in the news following the March 14th proposal by the EPA to lower the enforceable levels of PFAS in drinking water to 4 parts per trillion (ppt) for each of the two most common PFAS compounds, PFOA and PFOS.
Four other common PFAS compounds cannot exceed “a Hazardous Index of 1.0” (no units given).
They also propose a “goal” for PFOA and PFOS of zero ppt and of 1.0 ppt for the PFAS mixture, an amount that is vanishingly small. This health-based goal, though non-mandatory, is founded on identified risks of cancer and indicates there is really no safe level of exposure to these compounds. PFAS are also linked to increased cholesterol levels, abnormal liver enzyme profiles, reproductive damage, and depressed immunity, including ineffective vaccination in children.
Presently Vermont allows a Maximum Contaminant Level of PFAS in drinking water of 20 ppt for the combination of five PFAS compounds, including PFOS and PFOA.
More than 9,000 PFAS compounds exist, and, in addition to their high chemical stability, they are remarkably mobile in the environment. PFAS are notoriously prevalent in the groundwater around landfills, and even Thetford has its share thanks to the closed Upper Valley Regional Landfill in Post Mills. Contaminants leaching from the landfill have been monitored in water from peripheral test wells since 2001 when the landfill was capped to stop further water infiltration. However the State did not test for PFAS until 2018, and they only measured one well, the most distant from the landfill. PFAS was detected at 21 ppt — just above the VT allowed level of 20 ppt. In 2021 that same well showed almost a doubling of PFAS levels to 39.77 ppt. Another well, never before tested, showed 20.07 ppt in 2020. There is too little data to draw conclusions. In light of the EPA’s proposal to enforce lower PFAS levels, it is imperative that this testing be continued and extended to nearby private wells, particularly since the landfill’s impervious cap is aging.
The report of PFAS in a well at Thetford Academy in 2021 might be an anomaly, but it shows these chemicals can crop up in places other than landfills. In fact, PFAS have been found in the drinking water and ground water of more than 2,800 communities. But the true scale of contamination is likely much greater, because PFAS have been around for almost 80 years.
in 1946 the chemical giant DuPont introduced Teflon, a slippery coating made from PFAS. People were delighted by the innovation of the non-stick frying pan. Today PFAS are ubiquitous in consumer products such as baby textiles (bedding, bibs, changing pads, nursing pillows, etc.), sports shoes, waterproof jackets, dental floss, swimwear, cookware, electronics (like smudge-resistant touch screens), food packaging, pet food bags, cosmetics, carpets, greaseproof and waterproof coatings like Scotchgard, and products like GoreTex. PFAS-based waxes on skis and snowboards leave a trail of forever chemicals wherever they are used.
PFAS are also utilized in military equipment, house construction, automobiles, solar panels, rechargeable batteries, and medical devices. The list goes on. The most notorious ones, PFOA and PFOS, are components of fire-fighting foams for flammable liquid fires because they have surfactant properties that allow the foam to spread and suppress the fire. This use makes the foams a major source of PFAS pollution worldwide.
The plethora of everyday uses is at odds with the fact that PFAS have been suspect from the start. In 1950 the 3M corporation, one of the foremost manufacturers of PFAS, had evidence that PFAS — which are not biodegradable — can build up in the blood of mammals. By the 1960s both 3M and DuPont were aware that PFAS posed health risks. But they continued to conceal this from their employees and the public. A 1965 study on rats by DuPont showed that PFAS caused abnormal changes in organs, and in 1966 the FDA thankfully rejected a petition by DuPont to use PFAS as a food additive. Liver damage from PFAS in food packaging was shown in a study by DuPont in 1973, and in 1977 3M found that the water-repellent PFOS, used in their Scotchgard fabric treatment, was “more toxic than anticipated.” By 1989 workers exposed to PFAS at 3M facilities were showing elevated cancer rates. The movement of PFAS through the food chain was documented by scientists at 3M in 1998, and in 1999 a 3M researcher called PFOS “the most insidious pollutant since PCBs.”
Indeed, since these studies, PFAS have been found in 99% of Americans and in more than 330 wildlife species from the poles to the tropics, including rare, threatened, and endangered animals. High levels are present in freshwater fish.
Large amounts of PFAS get into the environment from manufacturing and industrial sources, firefighting, landfills, and other waste disposal. Trash incinerators that were not designed to burn PFAS have caused widespread pollution of downwind areas with PFAS, for instance, in Cohoes, NY. In fact, it is doubtful that incineration can actually destroy PFAS. The EPA writes in a technical bulletin, “PFAS compounds are difficult to break down due to fluorine’s electronegativity and the chemical stability of fluorinated compounds. Incomplete destruction of PFAS compounds can result in the formation of smaller PFAS products ….”
On an everyday level, the water-repellent coating of any PFAS-treated item such as outerwear or furnishings emits PFAS dust, and this is exacerbated by aging of the item and washing.
The EPA has until September 3, 2024, to finalize the proposed new drinking water standards. After that, drinking water utilities will likely have three to five years to comply. The proposed standard is limited to six notorious PFAS compounds. Water treatment technologies installed to comply with the new regulations will mean other PFAS will effectively be treated, too, which will reduce total PFAS levels in drinking water. But beware, not all filters do a good job.
Under mounting pressure, 3M says it will end the manufacture of PFAS and discontinue their use in its products by the end of 2025. But there has been no statement from DuPont. An estimated 47,000 tons of PFAS have already been released from consumer products into the environment.
One can limit exposure to PFAS by avoiding fast food and greasy carryout food in PFAS-lined “paper” containers; GoreTex and other stain- or water-repellent clothing or fabric with the labels Teflon, Scotchgard, Polartec, Stainmaster, and others; microwave popcorn bags (PFAS treated interior); stain-repellent soft furnishings and sprays; kitchen utensils containing PTFE; and some dental floss, e.g. Glide.
And the wristband of the Apple Sport Watch contains PFAS, too.