The C8 Health Project: Design, Methods, and Participants
Frisbee, Stephanie J., Brooks, A. Paul, Jr., Maher, Arthur, Flensborg, Patsy, Arnold, Susan, Fletcher, Tony, Steenland, Kyle, Shankar, Anoop, Knox, Sarah S., Pollard, Cecil, Halverson, Joel A., Vieira, Veronica M., Jin, Chuanfang, Leyden, Kevin M., Ducatman, Alan M., Environmental Health Perspectives
BACKGROUND: The C8 Health Project was created, authorized, and funded as part of the settlement agreement reached in the case of Jack W. Leach, et al. v. E.I. du Pont de Nemours & Company (no. 01-C-608 W.Va., Wood County Circuit Court, filed 10 April 2002). The settlement stemmed from the perfluorooctanoic acid (PFOA, or C8) contamination of drinking water in six water districts in two states near the DuPont Washington Works facility near Parkersburg, West Virginia.
OBJECTIVES: This study reports on the methods and results from the C8 Health Project, a population study created to gather data that would allow class members to know their own PFOA levels and permit subsequent epidemiologic investigations.
METHODS: Final study participation was 69,030, enrolled over a 13-month period in 2005-2006. Extensive data were collected, including demographic data, medical diagnoses (both self-report and medical records review), clinical laboratory testing, and determination of serum concentrations of 10 perfluorocarbons (PFCs). Here we describe the processes used to collect, validate, and store these health data. We also describe survey participants and their serum PFC levels.
RESULTS: The population geometric mean for serum PFOA was 32.91 ng/mL, 500% higher than previously reported for a representative American population. Serum concentrations for perfluoro-hexane sulfonate and perfluorononanoic acid were elevated 39% and 73% respectively, whereas perfluorooctanesulfonate was present at levels similar to those in the U.S. population.
CONCLUSIONS: This largest known population study of community PFC exposure permits new evaluations of associations between PFOA, in particular, and a range of health parameters. These will contribute to understanding of the biology of PFC exposure. The C8 Health Project also represents an unprecedented effort to gather basic data on an exposed population; its achievements and limitations can inform future legal settlements for populations exposed to environmental contaminants.
KEY WORDS: C8, environmental contamination, perfluorocarbons, PFOA, toxic tort settlement. Environ Health Perspect 117:1873-1882 (2009). doi:10.1289/ehp.0800379 available via http://dx.doi.org/ [Online 13 July 2009]
Perfluorooctanoatic acid (PFOA, or C8) is one member of the class of man-made perfluorocarbon (PFC) compounds. PFOA exists as an alkyl acid (PFOA), an ammonium salt (ammonium perfluorooctanoate (APFO)], or as a dissociated conjugate base [perfluorooctanoate (PFO)]. A closely related PFC is perfluorooctanesulfonate (PFOS; C8 sulfonate, or C8S). Additional, related PFCs include C5 [perfluoropentanoic acid (PFPeA)], C6 [perfluorohexanoic acid (PFHxA)], C6 sulfonate [perfluorohexane sulfonate (PFHS)], C7 [perfluoroheptanoic acid (PFHpA)], C9 [perfluorononanoic acid (PFNA)], C10 [perfluorodecanoic acid (PFDA)], C11 [perfluoroundecanoic acid (PFUnA)], and C12 [perfluorododecanoic acid (PFDoA)]. PFCs are used as plasticizers, wetting agents, and emulsifiers during the manufacture of fluropolymers, including products that impart nonstick heat resistance to cookware or breathable yet waterproof properties to fabrics. PFCs may also result from the metabolism or environmental breakdown of fluorinated telomers, including chemicals, used to coat commercial food packaging and for stain-resistant treatment tor fabrics and clothing. PFOA may also be a residual impurity in personal care products.
PFCs and health. PFOA and other PFCs persist in the environment and are found in groundwater and surface water worldwide (Yamashita et al. 2008). They are present in blood and other tissues of animal species throughout the world, including remote regions (Tao et al. 2006). Recent publications have extensively reviewed and summarized the known toxicologic properties, environmental distribution, and potential health concerns related to PFOA (Kennedy et al. …