On March 4, 2020, scientists from the Environmental Working Group (EWG) and Indiana University published a peer-reviewed article investigating 26 per- and polyfluoroalkyl substances (PFAS) and finding that all exhibit at least one or more characteristics of known human carcinogens. The authors reviewed existing epidemiological, toxicological, and mechanistic data for the set of PFAS and applied the Key Characteristics of Carcinogens framework for identification of cancer hazards (FPF reported). The study concludes that there is “strong evidence that multiple PFAS induce oxidative stress, are immunosuppressive, and modulate receptor-mediated effects” as well as “suggestive evidence indicating that some PFAS can induce epigenetic alterations and influence cell proliferation.” The data also showed that PFAS are not genotoxic and do not generally undergo metabolic activation. Not enough information was available, however, to assess whether PFAS promote chronic inflammation, cellular immortalization, or alter DNA repair.
“Our research has shown that PFAS impact biological functions linked to an increased risk of cancer,” said Alexis Temkin, EWG toxicologist and lead author of the study, in the organization’s press release. “This is worrisome, given that all Americans are exposed to PFAS mixtures on a daily basis, from contamination in water, food and everyday products.” Two of the most well studied PFAS, perfluorooctanoic acid (PFOA; CAS 335-67-1) and perfluorooctanesulfonic acid (PFOS; CAS 1763-23-1), were found to exhibit up to five key characteristics of known carcinogens, which the authors write “can serve as research priorities for less-studied PFAS as well as sources of information for potential application of read-across approaches to unstudied endpoints for other PFAS class members.” Even with the existing data gaps surrounding human epidemiology and mechanistic aspects, the authors see the key characteristics approach as potentially “useful for categorizing the carcinogenic hazards of PFAS that have not undergone systematic testing.”
EWG (March 4, 2020). “Study: PFAS Act Similar to Known Cancer-Causing Chemicals.”
BuzzFeed News (March 4, 2020). “Here Are The Ways That PFAS Chemicals Might Cause Cancer, A New Study Says.”
American Chemistry Council (March 4, 2020). “EWG Approach ‘No Better Than Chance’ At Predicting Carcinogens.”
Amanda Ulrich (March 18, 2020). “PFAS study pointing to carcinogenicity sparks debate.” Chemical Watch
Temkin A. et al. (March 4, 2020). “Application of the Key Characteristics of Carcinogens to Per and Polyfluoroalkyl Substances.” Int. J. Environ. Res. Public Health, 17(5).