Research Helps Clean Up a Water Supply
Tillett, Tanya, Environmental Health Perspectives
Many of the conveniences of modern life are made possible with man-made compounds. One such chemical, perfluorooctanoic acid (PFOA), has a broad spectrum of use, from the manufacture of non-stick cookware to aerospace technology. PFOA's persistence in the environment is troubling, especially given studies demonstrating that exposure to the compound can cause developmental delays and cancer in lab animals. Thus, when PFOA was detected in the water supply of Little Hocking, a village located across the Ohio River from and downwind of a Washington, West Virginia, fluoropolymer manufacturing facility, researchers at the University of Pennsylvania NIEHS Center of Excellence in Environmental Toxicology (CEET) felt compelled to investigate. The contamination was first reported to Hong Zhang, a local doctor enrolled in a practicum residency for physicians in occupational and environmental medicine at the university.
According to CEET deputy director Edward Emmett, who also directs the center's Community Outreach and Education Core, the research team's immediate focus was on determining whether, how, and to what extent Little Hocking residents were being exposed to PFOA. The CEET investigators joined with community partners Grand Central Family Medicine in Parkersburg, West Virginia, and the Decatur Community Association in Cutler, Ohio, to design a study, recruit study participants, and collect data. The group applied for and received an environmental justice grant from the NIEHS, and began work in July 2004.
The investigators distributed questionnaires to a random sampling of residents who used either private or public drinking water sources, and examined blood serum samples to assess PFOA concentrations. PFOA water concentrations were obtained from the Ohio EPA. Levels averaged 3.55 ng/mL in 2002-2005, some of the highest ever reported in public water supplies in the United States.
Overall, blood serum analysis showed that the residents' levels were 60-75 times higher than in the general U.S. population. The investigators found that serum PFOA was especially high in those who ate more home-grown fruits and vegetables. Emmett says it is unclear if this was due to PFOA making its way into the fruits and vegetables themselves, or to PFOA in water used for cooking, canning, and cleaning.
An air dispersion model based on estimated emissions from the Washington plant revealed that serum PFOA levels were no different for those people living in areas with higher air concentrations than for those living where there was minimal PFOA in the air. …