By EWG Research Analyst Paul Pestano, M.S. and Senior Scientist Olga Naidenko, Ph.D.
In March, DuPont
, the behemoth chemical company whose factories have polluted groundwater in several communities in West Virginia, Ohio and New Jersey, agreed to pay $8.3 million to provide water filters for 4,800 homes in southern New Jersey.
In all three locations, DuPont's plants contaminated drinking water with perfluorooctanoic acid (PFOA or C8), an industrial chemical that is persistent in humans and the environment and has been linked to endocrine disruption, reproductive toxicity, damage to the immune system and elevated risk of cancer and heart disease.
Now, two new published studies have provided fresh evidence of PFOA's potential to cause harm even at low levels. And yes, this is something to pay attention to, since PFOA belongs to a class of chemicals called perfluorochemicals, or PFCs, that have been found in over 98% of all Americans.
PFCs and Early Menopause
One recent study done at West Virginia University's School of Medicine found a link between PFC levels in a woman's body and the timing of the onset of menopause. Adjusting for other factors that can affect the timing of menopause, such as age, smoking and exercise level, the study found that increased exposures to PFCs correlated with lower levels of sex hormones -- and earlier menopause.
Lead author Dr. Sarah Knox told EWG in a phone interview, "We believe these results are clinically disturbing. They're a red flag."
While the levels of PFOA in the women studied were higher than the national average, the level of PFOS in participants was similar to that commonly found in the U.S. population.
As in all epidemiological studies, establishing causality remains a challenge, so follow-up research will be essential. Scientists are necessarily cautious about drawing definitive conclusions, and this study does not prove definitely that it was PFCs specifically that caused early menopause. The results agree with findings in laboratory animal and occupational studies.
Low-dose PFOA Exposure and Breastfeeding
The mice were given drinking water containing PFOA, much like the water that residents of the polluted communities have been drinking for years. What is most noteworthy, however, was that PFOA was found to affect mice at levels nearly ten times lower than the levels found in humans drinking PFOA-contaminated water.
The U.S. Environmental Protection Agency is requiring companies to phase out use and manufacture of PFOA by 2015, but by then, certain populations will have been drinking tainted water for decades.
What can you do?
Even without exposure to PFOA-contaminated drinking water, PFC concentrations slowly build up in the body from a lifetime of exposure to PFC-containing consumer products such as food packaging
or stain-resistant and waterproof clothing
. Although long-term exposures cannot be reversed overnight, it makes sense to take small steps to minimize exposures.