There is growing concern about PFOA and PFOS levels in US drinking water. In November 2017, the EPA issued a Technical Fact Sheet addressing PFOS and PFOA, the most widely studied of the PFAS group of chemicals. It is worth noting that both of these contaminants are detectable by Lishtot’s proprietary water tester, the TestDrop Pro.
The PFAS group is made up of two subgroups: perfluoroalkyl substances and polyfluoroalkyl substances. PFOS and PFOA are perfluoroalkyl substances (compounds for which all hydrogens on all carbons (except for carbons associated with functional groups) have been replaced by fluorines). In contrast, polyfluoroalkyl substances are compounds for which some hydrogens (but not all) on the carbon atoms have been replaced by fluorines. PFASs are extremely persistent in the environment primarily because the chemical bond between the carbon and fluorine atoms is extremely strong and stable.
PFOS and PFOA are manmade and do not occur naturally in the environment. PFOS and PFOA are produced in large amounts in the US for use in a variety of industrial and consumer products. Because of their unique ability to repel oil and water, these chemicals have been used in: surface protection products such as carpet and clothing treatments; coatings for paper, cardboard packaging and leather products; industrial surfactants, emulsifiers, wetting agents, additives and coatings; processing aids in the manufacture of fluoropolymers such as nonstick coatings on cookware; membranes for clothing that are both waterproof and breathable; electrical wire casing; fire and chemical resistant tubing; and plumbing thread seal tape.
Through 2001, PFOS and other PFAS chemicals were used in the manufacture of aqueous film forming foam (AFFF), which is used to extinguish liquid hydrocarbon fires. Manufacturers of AFFF in the United States now use PFASs other than PFOS; however, existing stocks of PFOS-based AFFF remain in use. By 2002, the primary U.S. manufacturer of PFOS voluntarily phased out production of PFOS. In 2006, eight major companies in the PFASs industry voluntarily agreed to phase out production of PFOA and PFOA-related chemicals by 2015. The EPA is concerned about a limited number of ongoing uses of PFOA-related chemicals, which are still available in existing stocks and from companies not participating in the PFOA Stewardship Program. In addition, exposure can occur via goods that are imported from countries where PFOS and PFOA are still freely used.
PFASs have therefore been released into the environment through industrial manufacturing and the use and disposal of PFAS-containing products. During manufacturing processes, PFASs were released into the air, water, and soil in and around manufacturing facilities. Recently, PFOS and PFOA contamination has also been observed in facilities using PFAS products to manufacture other products. PFOS has been detected in surface water and sediment downstream of production facilities and in wastewater treatment plant effluent, sewage sludge, and landfill leachate at a number of cities in the United States. The environmental release of PFOS-based AFFF may also occur from tank and supply line leaks, use of aircraft hangar fire suppression systems, firefighting training activities, and use at airplane crash sites.
Because PFOS and PFOA are extremely stable and resistant to typical environmental degradation processes, they are persistent in the environment. They are widely distributed across all trophic levels and are found in soil, air, and groundwater at sites across the United States. They are known to bioaccumulate in humans and wildlife and are readily absorbed after oral exposure, accumulating primarily in the blood serum, kidney, and liver. Studies have found PFOS and PFOA in the blood samples of the general human population and wildlife, indicating that exposure to the chemicals is widespread. Reported data indicate that blood serum concentrations of PFOS and PFOA are higher in workers and individuals living near facilities that use or produce PFASs than in the general population. Potential exposure pathways include ingestion of food and water, use of consumer products or inhalation of PFAS-containing particulate matter (e.g., soils and dust) or vapor phase precursors. PFOA and PFOS have been found in drinking water supplies typically associated with manufacturing locations, industrial use or disposal.
The toxicity, mobility, and bioaccumulation potential of PFOS and PFOA result in potential adverse effects on the environment and human health. Toxicological studies on animals indicate potential developmental, reproductive, and systemic effects. Human epidemiological studies found associations between PFOA exposure and high cholesterol, increased liver enzymes, decreased vaccination response, thyroid disorders, pregnancy-induced hypertension and preeclampsia, and cancer (testicular and kidney). Human epidemiological studies found associations between PFOS exposure and high cholesterol and adverse reproductive and developmental effects. PFOS and PFOA are toxic to laboratory animals, producing reproductive, developmental and systemic effects in laboratory tests. The EPA found that there is suggestive evidence that PFOS and PFOA may cause cancer. The American Conference of Governmental Industrial Hygienists (ACGIH) has classified PFOA as a Group A3 carcinogen – confirmed animal carcinogen with unknown relevance to humans. The World Health Organization’s International Agency for Research on Cancer has found that PFOA is possibly carcinogenic to humans.
In general, PFOS and PFOA resist most conventional chemical and microbial treatment technologies. The most common groundwater treatment method is extraction and filtration through granular activated carbon filters.
In May 2016, the EPA established drinking water health advisories of 70 parts per trillion (PPT) for the combined concentrations of PFOS and PFOA. For water above 70 PPT, the EPA recommends that drinking water systems take steps to assess contamination, inform consumers, and limit exposure. In 2016, the Environmental Working Group published an analysis of EPA data, and reported that unsafe levels of PFOA/PFOS were found in public water systems serving 5.2 million people in the US. The analysis was based on monitoring reports submitted to the EPA by 52 different water systems spread out over 19 states and 2 territories. (While the EPA health advisory is set at 70 parts per trillion, Lishtot’s personal water tester is sensitive enough to detect 1 PPT.) As of late 2017, there are no US federal drinking water standards for PFOA or PFOS.
In 2018, using information gained through a Freedom of Information Act request, it was learned that the EPA, the White House, and the Department of Health and Human Services had decided to withhold the results of a PFOS/PFOA study done by the Agency for Toxic Substances and Disease Registry that had been planned for publication. The study showed that they endanger human health at a far lower level than the EPA has previously considered safe.
On May 22-23, 2018, the EPA hosted a National Leadership Summit in Washington D.C. to take action on PFAS in the environment. During the summit, participants worked to 1) share information on ongoing efforts to characterize risks from PFAS and develop monitoring and treatment/cleanup techniques, 2) identify specific near-term actions, beyond those already underway, that are needed to address challenges currently facing states and local communities, and 3) develop risk communication strategies that will help communities address public concerns with PFAS.
In the weeks following the summit, the EPA plans to travel to a number of communities impacted by PFAS. In so doing, the EPA intends to hear directly from the public how to best help communities facing this issue. Using information from the Summit, community engagements, and public input provided by the docket, the EPA plans to develop a PFAS Management Plan for release later this year, in Fall 2018.
There are many unanswered questions with regard to PFOA/PFOS and US drinking water and only some of those questions will be answered by the EPA in the coming months. In the interim, people have a right to know what’s in their water. Lishtot is encouraging anyone who can to click to view our Global Water Map to see if you are in an area that is potentially exposed. In addition, our personal water tester, the TestDrop Pro, can tell you quickly and efficiently whether your water contains unsafe levels of PFOA/PFOS. For more information or to place an order,click here.
Also, take a look at our FAQ section for answers to common user questions.