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DEVELOPMENTAL TOXICITY OF PFOS AND PFOA
Citation:
LAU, C. S. DEVELOPMENTAL TOXICITY OF PFOS AND PFOA. Presented at 8th Annual National Forum on Contaminants in Fish, Baltimore, MD, September 18 - 21, 2005.
Description:
Perfluoroalkyl acids (PFAA) are fully-fluorinated organic chemicals with a carbon backbone (typically varying from C-4 to C-14) and a functional group (usually carboxylic acid or sulfonic acid). These chemicals are man-made, exceptionally stable to metabolic and environmental degradation, and possess surfactant properties that lead to wide consumer and industrial applications. These uses include coatings for fabrics, carpets, and paper products approved for food contact, fire-fighting foam, and production of fluoropolymers and fluoroelastomers. The most widely used PFAA acids in commerce are the C-8 forms such as Perfluorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA) and the telomer alcohol (which is metabolized to PFOA). Both PFOS and PFOA have been detected recently in humans and wildlife. Importantly, these chemicals are readily absorbed but poorly eliminated. In humans, elimination half-lives of 5.4 and 3.8 years have been estimated respectively for PFOS and PFOA. In 2003, production of PFOS was phased out by its manufacturer, but it has been replaced in commerce by PFOA primarily and other PFAA of different carbon chain length. Developmental toxicity studies with PFOS and PFOA have been conducted in our laboratory in the past few years with rodent models. Both chemicals produced maternal toxicity; deficits of maternal weight gains and liver enlargement were common features. Neither chemical was remarkably teratogenic and effects of prenatal exposure were mostly comprised of delayed development. Newborns from PFOS-treated rats and PFOA-treated mice were delivered live but neonatal mortality was observed in the ensuing hours and days, in a dose-dependent manner. A similar pattern of postnatal growth retardation was seen with PFOS and PFOA treated pups. Our results therefore suggest developmental toxicity for both C-8 PFAA, and underscore potential common mechanisms of toxicity shared by the entire class of these chemicals. This abstract does not necessarily reflect EPA policy.