For the first time, scientists reviewed 26 types of per- and polyfluoroalkyl substances (PFAS) and found that they all display at least one characteristic of cancer-causing chemicals that can alter crucial bodily functions. The new study comes on the heels of alarming laboratory tests that detected many of these “forever chemicals” in tap water sampled across the country and suggest that fluorinated compounds in the PFAS family have contaminated virtually every major source of drinking water in the United States.
PFAS are in a broad group of chemicals used in an array of consumer products and industrial processes for their nonstick, stain-repellent and waterproofing properties. The substances trace their chemical roots back to perfluorooctanoic acid (PFOA), the chemical originally used to make Teflon for non-stick cookware.
PFOA and perfluorooctanesulfonic acid (PFOS), the chemical originally used to make 3M’s Scotchgard, were phased out after PFAS pollution contaminated local communities and raised mounting environmental health concerns. Both PFOA and PFOS are categorized as PFAS, but today, there are hundreds of other PFAS chemicals. The industry has introduced dozens of new compounds it claims are safer for humans and the environment because they made up by shorter, less-complex chains of fluorinated carbons.
However, at least one class of replacements, known as GenX chemicals, caused tumors and damage to the liver, kidney and immune system in animal studies, according to the Environmental Protection Agency (EPA). Now a new study released by the Environmental Working Group suggests more than at least a dozen different PFAS compounds display some of the same “key characteristics” of PFOS and PFOA that are linked to an increased risk of cancer.
PFOS and PFOA are the most well studied PFAS, and have been linked to a number of health problems, including increased cholesterol levels, liver dysfunction and weakened immune systems in children. The International Agency for Research on Cancer classified PFOA as a “possible human carcinogen” and the EPA says there is some evidence to suggest PFOS and PFOA may increase cancer risks.
Scientists have long suspected that closely-related PFAS chemicals pose similar health risks, but few have undergone rigorous safety testing, and data on how the substances react in the bodies of humans and animals tends to be scant. Still, millions of people are exposed to PFAS from a multitude of sources, including food packaging and drinking water.
“The short-chain and replacement chemicals, while they are not complete in data, do exhibit some of the similar characteristics as the well studied ones, and that’s concerning because we know we are exposed to them in drinking water, for example,” said Alexis Temkin, an Environmental Working Group toxicologist and the primary author of the new study.
Temkin worked with researchers at Indiana University to review all the publicly available data on 26 different PFAS chemicals, including PFOS and PFOA. The team found “strong evidence” that multiple PFAS suppress the immune system and interfere with cell growth and hormonal signaling, all factors associated with carcinogenicity.
While PFOS and PFOA displayed five characteristics associated with an elevated risk of cancer, the rest of the PFAS substances under review displayed at least one of these key characteristics. This suggests they may be safer than the original PFAS chemicals, but not safe enough to subject the public to widespread exposure. Temkin said the majority of PFAS the team reviewed have what’s known as “receptor mediated effects” that may alter critical bodily functions such as hormonal signaling and cell growth.
““The majority of them have what’s called receptor mediated effects,” Temkin said. “A lot of these chemicals can either bind or interact with receptors that control cell growth, or hormonal signaling like the estrogen receptor, which can play a role in breast cancer and reproductive organ cancers,” Temkin said.
To be clear, the study did not determine that PFAS cause cancer, but there is evidence to suggest that various PFAS substances act similarly to known cancer-causing substances by disrupting bodily systems. People are exposed to toxins all the time, and determining cancer risk is complicated. Temkin said more research is needed to understand how these chemicals may contribute to health problems and how the body reacts to different combinations of various PFAS substances.
“We have multiple routes of exposure, but not complete safety testing data,” Temkin said, adding no knew tests were conducted for the study and the researchers did not use data obtained from the industry, which often shields research from the public.
PFAS are “persistent” chemicals, which means they do not break down easily in the human body and the environment, allowing contamination to spread indefinitely. Last month, the EWG released laboratory tests of tap water sampled from 44 cities and towns across the country, and 43 came back positive for some level of various PFAS substances. Some of the highest levels were detected in major metropolitan areas, including New Orleans, Miami and Philadelphia.
The only tap water free of PFAS was sampled from Meridian, Mississippi, which draws its water from deep underground wells. Alongside previous tests and research, the findings suggest that major sources of drinking water such as rivers and lakes are contaminated with small but detectable levels of “forever chemicals” that will remain in the environment for years. Thanks to PFAS persistence and various sources of PFAS pollution, scientists now believe everyone living in the U.S. likely has some level of PFAS in their bodies.
Politicians and regulators are now scrambling to address a silent public health crisis that is only growing in scope as scientists continue to uncover new information about the health dangers of PFAS and its pervasiveness in the environment.
The EPA has a PFAS “action plan,” but the agency only recently began the regulatory process for setting mandatory federal limits for PFOS and PFOA in drinking water. The regulations could be years in the making and would not cover hundreds of additional PFAS chemicals, which Congress recently added to a national database that tracks toxic substances released into the environment. President Trump has threatened to veto legislation passed by House Democrats that would require the EPA to establish tough standards for PFAS in drinking water and designate PFOS and PFOA as hazardous substances under federal law. The EPA would have five years to determine whether other PFAS should be classified as hazardous, but the legislation is stalled in the Republican-controlled Senate.
The EPA has come under fire for dragging its feet in responding to PFAS and now says regulators are investigating polluters on criminal charges. Environmentalists recently sued the Department of Defense for using incinerators to destroy firefighting foam containing PFAS that has contaminated Air Force bases across the country, in part because nearby residents were concerned about the spread of pollution. That’s an alarming sign that there is no easy fix for cleaning up chemicals that tend to stick around and turn up everywhere.
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