What you need to know about PFASs
Most contaminants share a common trait: If you stop their release, then the ecosystem will dilute concentrations or degrade the contaminants until they are no longer a threat to human health or the environment. A greater focus on poly- and perfluoroalkyl substances (PFASs), though, is showing that these compounds appear to move great distances freely and never break down.
PFASs are manmade, yet they have been detected in the Arctic Circle and other remote locations such as open ocean waters, indicating that they travel via wind and water. Exposure to PFASs is already so widespread that they were detected in 95 to 100 percent of human blood samples in 1999-2000 and 2003-2004. Due to the strength of their bonds, PFASs are not easily biodegraded by exposure to water, wind, or other factors present in the environment. This combination of factors could create an enormous problem for the scientific and medical communities if it is confirmed that PFASs increase the likelihood of certain medical conditions in humans, even as new production of these compounds is waning.
PFASs are a broad group of chemicals used to make products more resistant to stains and water damage. Industrial quantities of PFASs—the two most popular being perfluorooctanoic acid (PFOA), which is used to make DuPont’s Teflon; and perfluorooctane sulfonate (PFOS), used to make 3M’s Scotchgard—have been manufactured since the 1940s.
PFASs are very stable in the environment, low in volatility, and resistant to biodegradation, photooxidation, direct photolysis, and hydrolysis. Because of this, they are ubiquitous: PFASs have been used in firefighting foams for suppressing gas fires, nonstick pans, Gore-Tex and other waterproof clothing, electrical wire casings, fire- and chemical-resistant tubing, plumbing thread seal tape, eyeglasses, tennis rackets, stain-proof coatings for carpets and furniture, fast-food wrappers, microwavable popcorn bags, bicycle lubricants, satellite components, ski wax, car seats, tents, shoes, and pizza boxes. They have also been used as friction reducers in the aerospace, automotive, building and construction, and electronics industries. The massive insertion of PFASs into everyday products has led to widespread human exposure.
Food and water ingestion are the primary sources of human exposure to PFASs. Another common exposure is from PFAS-treated carpets and upholstery—especially for children through hand-to-mouth transfer. Research suggests that exposure from consumer products is usually low, especially when compared to exposure through contaminated drinking water or occupational exposure.
People working where PFASs are made or used are often exposed to higher levels than the general population. Higher-risk occupations include chemical plant workers, carpet layers, and certain firefighters. Some communities near facilities where PFASs were previously manufactured show high levels of these substances in drinking water supplies, which can lead to high rates of ingestion for these populations. Similarly, PFASs have been released into soil and groundwater in areas where firefighting foams containing the substances were used (on military bases, in particular).
Once present, the most commonly used PFASs remain in the human body for many years; elimination half-times in humans are 3.8 years and 5.4 years for PFOA and PFOS, respectively. It should be noted that although recent monitoring data continues to show widespread human exposure, the U.S. Department of Health and Human Services has observed that the levels of PFASs in Americans’ blood appear to be declining.
The ubiquity of PFASs and the associated health and environmental consequences have caught the insurance industry’s attention. While coverage for this exposure is generally available in site-pollution policies, underwriters are increasingly cautious. Sites that manufacture PFASs are obvious higher-risk exposures, but underwriters are also scrutinizing manufacturers that used PFASs in their own products and even facilities that simply used products containing PFASs, like firefighting foams. In most cases, the risks at these locations have not been quantified as PFASs are not commonly tested for in soil and groundwater sampling or in waste streams and wastewater treatment systems.
There have been no definitive studies linking the presence of PFASs in the body to any specific disease or disorder, but testing on animals has produced results that have concerned government agencies and the insurance industry—and led to a spate of lawsuits, mostly unresolved, relating to PFAS exposure. In animal studies, some PFASs disrupt endocrine activity; reduce immune function; cause adverse effects to the liver, pancreas, and thyroid; create changes to blood cholesterol and triglyceride levels; and cause developmental problems in offspring exposed in the womb. PFASs potentially acting as “endocrine disrupters” has been of particular concern since other such disrupters, such as the pesticide DDT, have been shown to cause cancers and birth defects in humans.
PFASs can be disposed of by filtering to separate solids from liquid waste and then disposing of the dry PFAS solids in an approved industrial solid waste landfill, or incinerating them at temperatures of 800°C. Alternatively, public water systems can treat PFAS-impacted water with activated carbon or reverse osmosis systems. As a general rule, though, PFASs in air or water go untreated unless localized land use and sampling verify that there are very high levels present in the community.
Today, PFASs are considered “emerging contaminants” and are not subject to federal regulation. This is because, under the Safe Drinking Water Act, it takes years of study to develop enough data on toxicity for agencies like the Environmental Protection Agency (EPA) to enact regulations, and also because there are so many poly- and perfluoroalkyl variants that it is difficult to assess the risk potential across the entire chemical class.
In 2012, the EPA listed a number of perfluoroalkyl compounds—including prominent PFASs such as PFOA and PFOS—as suspected drinking water contaminants. In May 2016, the EPA published health advisory guidelines for PFOS and PFOA that suggest prolonged exposure over 70 parts-per-trillion can cause health problems; this is equal to about a drop of water in 20 Olympic-sized swimming pools. Since 2013, an EPA-mandated testing program has detected elevated levels of the chemicals in 52 public water systems across the country. Those systems had at least one sample contaminated with either PFOA or PFOS at an amount greater than the new lifetime health advisory level.
Meanwhile, states like Minnesota, Michigan, and Alabama have issued advisories cautioning consumers to either stop or limit eating fish from waters containing PFOA or PFOS. Many states, such as Michigan, have set non-enforceable exposure thresholds even lower than the EPA (in Michigan, it is 11 parts-per-trillion for PFOS and 42 parts-per-trillion for PFOA; levels that were exceeded in two of the state’s larger water systems). In New Jersey, which was the first state to issue guidance on thresholds for PFASs, the state’s Department of Environmental Protection announced it will set drinking water standard criteria at 14 parts-per-trillion and 13 parts-per-trillion for PFOA and another PFAS, called PFNA, respectively.
Chemical manufacturers have recently become responsive to concerns about PFASs and have begun phase-outs of these compounds. In 2006, eight major companies agreed to participate in the EPA’s voluntary PFOA Stewardship Program, which required commitments to reduce facility emissions and production of PFOA and related chemicals, and to work toward the eventual elimination of these substances. The chemical industry has responded to these phase-outs by shifting production to next-generation perfluoroalkyl compounds with smaller carbon chains. Small-chain compounds, while still persistent in the environment, are generally less toxic and less bio-accumulative.