Toxic Teflon: Compounds from Household Products Found in Human Blood

"Better things for better living -- through chemistry." From the 1940s to the 1980s, E.I. DuPont de Nemours and Co. wooed customers with that slogan, one of the most memorable in American advertising. But today, two groups of DuPont products developed during that era -- fluorotelomers and fluoropolymers -- are showing how chemical-dependent "better living" can come at a high price.

DuPont and other companies use those synthetic compounds to make an extraordinarily wide range of products, including nonstick cookware (e.g, Teflon), grease-resistant food packaging (e.g., microwave popcorn and pizza boxes), stain-resistant fabrics and carpets (e.g., Stainmaster), shampoos, conditioners, cleaning products, electronic components, paints, firefighting foams, and a host of other artifacts of modern life.

But like many "better things" produced by industrial chemistry, these products can have disastrous side effects. The chemicals used to make them or that are released when they decompose are especially troublesome. They can easily escape to roam freely around the planet, persist in the environment, contaminate the blood of people and wildlife, change body chemistry, and are accused of causing health problems, including cancer.

Supermolecules

After decades of harnessing the almost miraculous properties of fluorotelomers and fluoropolymers, scientists are now showing that compounds that are used in their manufacture or thrown off when they break down -- fellow members of the perfluorochemical (PFC) family -- are turning up in people and animals all over the planet.

Although DuPont has never conceded that PFCs might cause health or environmental problems, the company has bowed to relentless and rising public pressure in recent years and moved to rein in its emissions. But whatever action is taken at this point, a class of molecules that did not exist on the planet before the 20th century is now here to stay.

Chemical properties that make PFCs so useful in industry also make them virtually indestructible in nature. For sheer persistence, two members of the family, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), stand out. They are not broken down by heat, light, or microbes. Other PFCs do break down, but in doing so, most of them end up giving off PFOA or PFOS.

Of these two compounds' many disturbing properties, the one setting off the most alarm bells is their potential for causing cancer. Studies reported by the Environmental Protection Agency (EPA) (some of them conducted in the labs of Du Pont and a former producer, the 3M Company) have shown that rats fed PFOA were more likely to develop tumors in the pancreas, liver, testicles, and mammary glands. PFOS has been linked to liver and thyroid cancer in rats. A 1993 study found that 3M workers involved in manufacturing PFOA were three times as likely to die of prostate cancer as those who weren't (the difference was statistically significant, but because of the small number of deaths overall, the researchers warn that "results must be interpreted catiously.") Two of 3M's own studies also showed increased, but statistically nonsignificant, increases in prostate-cancer causing problems among PFOA workers. An EPA-appointed science advisory board has recommended labeling PFOA as "likely to be carcinogenic" in humans. DuPont has responded by maintaining that the "weight of evidence suggests that PFOA exposure does not cause cancer in humans," not exactly the kind of seal of approval you'd want to bet your family's health on.

In addition to developing cancers, rats and other laboratory animals fed varying amounts of PFOA have shown significantly increased rates of miscarriage, weight loss, and thyroid problems. Offspring of females fed the chemical had delayed growth but extra-fast sexual maturation. PFOS has caused a range of diseases in lab animals and shown a strong tendency to concentrate in humans and the wildlife food chain, prompting 3M to phase that chemical out of its big-selling Scotchgard fabric protector and other products in 2000-2002.