WASHINGTON - Scientists at the Environmental Working Group and Indiana University have for the first time conducted a review of 26 fluorinated chemicals, or PFAS, and found that all display at least one characteristic of known human carcinogens.
The study, published today in the International Journal of Environmental Research and Public Health, found that the most well-studied PFAS compounds - PFOA, formerly used by DuPont to make Teflon, and PFOS, formerly an ingredient in 3M's Scotchgard - exhibit up to five key carcinogenic characteristics.
"Our research has shown that PFAS impact biological functions linked to an increased risk of cancer," says Alexis Temkin, Ph.D., EWG toxicologist and the primary author of the new study. "This is worrisome, given that all Americans are exposed to PFAS mixtures on a daily basis, from contamination in water, food and everyday products."
Americans are exposed to hundreds of cancer-causing chemicals, many of which can build up in the body over time. Changes in the body, such as hormonal dysregulation and weakened immune system, increase cancer risk, and PFAS chemicals cause many such changes. The International Agency for Research on Cancer classifies PFOA as a possible human carcinogen. The U.S. Environmental Protection Agency says both PFOS and the PFOA replacement chemical GenX show evidence of carcinogenicity.
"Data from animal and epidemiological studies point to human health risks for PFAS, especially an elevated risk of cancer," said Lisa Kamendulis, an associate professor at Indiana University and one of the authors of the study.
PFAS chemicals never break down in the environment and can stay in the human body for many years. According to the new study, some so-called short-chain and replacement PFAS, touted by the chemical industry as safer alternatives to long-chain PFAS, exhibited the same key characteristics as the toxic chemicals they were designed to replace.
"We should focus on preventing cancer by preventing human exposure to potential carcinogens," said Olga Naidenko, Ph.D., vice president for science investigations at EWG. "Cancer causes staggering costs to society, and compelling evidence tells us that exposures to toxic chemicals in the environment are a significant risk factor."
In the C8 Health Project, which studied more than 70,000 people who lived or worked in the mid-Ohio Valley, where drinking water was contaminated with PFOA, elevated PFOA levels in the body were associated with greater risk of non-Hodgkin lymphoma and kidney, testicular, prostate and ovarian cancers.
In January, laboratory tests commissioned by EWG found the toxic PFAS chemicals in the drinking water of dozens of U.S. cities. Some of the highest PFAS levels detected were in samples from major metropolitan areas, including Miami, Philadelphia, New Orleans and the northern New Jersey suburbs of New York City.
Drawing on results from those tests and new academic research that found PFAS widespread in rainwater, EWG scientists believe PFAS is likely detectable in all major water supplies in the U.S., almost certainly in all that use surface water. EWG's tests also found chemicals from the PFAS family that are not commonly tested for in drinking water.
EWG's tap water samples, collected from May to December 2019, were analyzed for the presence of 30 different PFAS compounds by an accredited independent laboratory. That's five times as many chemicals as were tested for, from 2014 to 2015, in an EPA-mandated program that grossly underreported the true extent of contamination. On average, six or seven different PFAS chemicals were detected in samples.
In addition to elevated risk of cancer, exposure to PFAS chemicals is also linked to other serious health concerns, including reproductive and developmental harms, and reduced effectiveness of vaccines. Independent scientific studies have recommended a safe level for PFAS in drinking water of 1 part per trillion, a standard that is endorsed by EWG.
The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action.