WebMD: Why should we be worried about them?
Temkin: Peer-reviewed studies have linked exposure to these chemicals with weakened immune systems and lower vaccine effectiveness; low birth weights; endocrine disruption; thyroid disorders; increased cholesterol; hypersensitivity and greater risk of autoimmune diseases; and an increased risk of testicular, kidney, liver, and pancreatic cancers.
WebMD: How widespread are they, and where are they found?
Temkin: The CDC has found these chemicals in the blood of virtually all Americans. Last year, an American Red Cross study found that the blood of the average American has 4,300 parts per trillion, or ppt, of PFOS and 1,100 ppt of PFOA. (The two chemicals are types of per- and polyfluoroalkyl substances.)
These chemicals are found in upholstery treatments, carpet treatments, waterproof clothing, furniture, cosmetics, dental floss, nonstick cookware, food wrappers, sludge, food, and water.
WebMD: The New Food Economy did some testing and found PFAS chemicals in “green” molded fiber takeout bowls. Are the levels of chemicals they found cause for concern?
Blum: We don’t know the answer, but we believe that since PFAS chemicals will never break down in the environment and the ones that have been studied are toxic, we should only use them when they’re necessary, and they’re not necessary for food takeout containers.
Temkin: The results of this study help us understand where and how PFAS chemicals are used. When these bowls are composted, PFAS can contaminate the soil and potentially end up in the foods it is used on, or contaminate water, creating future exposures. There is a risk that PFAS can transfer to food in the bowls, which may be another source of PFAS exposure in the American diet.
WebMD: How dangerous are these chemicals?
Temkin: In June 2019, Linda Birnbaum, director of the National Institute for Environmental Health Sciences, suggested that the safety threshold for PFOA in drinking water should be as low as 0.1 parts per trillion, which is 700 times lower than the safety level set by the Environmental Protection Agency.
And a 2013 study by Philippe Grandjean, MD, of the Harvard School of Public Health, and Esben Budtz-Jórgensen, PhD, of the University of Copenhagen, made a recommendation for PFOA and PFOS in drinking water of 0.3 ppt. Grandjean published a case study on how regulatory guidelines and legal limits for the most-studied PFAS chemicals have decreased substantially since they first were proposed a decade ago.