Rate of decline in serum PFOA concentrations after granular activated carbon filtration at two public water systems in Ohio and West Virginia

Environ Health Perspect. 2010 Feb;118(2):222-8. doi: 10.1289/ehp.0901252.


Background: Drinking water in multiple water districts in the Mid-Ohio Valley has been contaminated with perfluorooctanoic acid (PFOA), which was released by a nearby DuPont chemical plant. Two highly contaminated water districts began granular activated carbon filtration in 2007.

Objectives: To determine the rate of decline in serum PFOA, and its corresponding half-life, during the first year after filtration.

Methods: Up to six blood samples were collected from each of 200 participants from May 2007 until August 2008. The primary source of drinking water varied over time for some participants; our analyses were grouped according to water source at baseline in May-June 2007.

Results: For Lubeck Public Service District customers, the average decrease in serum PFOA concentrations between May-June 2007 and May-August 2008 was 32 ng/mL (26%) for those primarily consuming public water at home (n = 130), and 16 ng/mL (28%) for those primarily consuming bottled water at home (n = 17). For Little Hocking Water Association customers, the average decrease in serum PFOA concentrations between November-December 2007 and May-June 2008 was 39 ng/mL (11%) for consumers of public water (n = 39) and 28 ng/mL (20%) for consumers of bottled water (n = 11). The covariate-adjusted average rate of decrease in serum PFOA concentration after water filtration was 26% per year (95% confidence interval, 2528% per year).

Conclusions: The observed data are consistent with first-order elimination and a median serum PFOA half-life of 2.3 years. Ongoing follow-up will lead to improved half-life estimation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Caprylates / blood*
  • Charcoal / chemistry*
  • Female
  • Filtration / methods*
  • Fluorocarbons / blood*
  • Humans
  • Male
  • Middle Aged
  • Ohio
  • Water Pollutants, Chemical / blood*
  • Water Purification / methods*
  • Water Supply / analysis*
  • West Virginia


  • Caprylates
  • Fluorocarbons
  • Water Pollutants, Chemical
  • Charcoal
  • perfluorooctanoic acid