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Guideline levels for PFOA and PFOS in drinking water: the role of scientific uncertainty, risk assessment decisions, and social factors

Journal of Exposure Science & Environmental Epidemiology (2019) | Download Citation



Communities across the U.S. are discovering drinking water contaminated by perfluoroalkyl and polyfluoroalkyl substances (PFAS) and determining appropriate actions. There are currently no federal PFAS drinking water standards despite widespread drinking water contamination, ubiquitous population-level exposure, and toxicological and epidemiological evidence of adverse health effects. Absent federal PFAS standards, multiple U.S. states have developed their own health-based water guideline levels to guide decisions about contaminated site cleanup and drinking water surveillance and treatment. We examined perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) water guideline levels developed by the U.S. Environmental Protection Agency (EPA) and state agencies to protect people drinking the water, and summarized how and why these levels differ. We referenced documents and tables released in June 2018 by the Interstate Technology and Regulatory Council (ITRC) to identify states that have drinking water and groundwater guideline levels for PFOA and/or PFOS that differ from EPA’s health advisories (HAs). We also gathered assessment documents from state websites and contacted state environmental and health agencies to identify and confirm current guidelines. Seven states have developed their own water guideline levels for PFOA and/or PFOS ranging from 13 to 1000 ng/L, compared to EPA’s HA of 70 ng/L for both compounds individually or combined. We find that the development of PFAS guideline levels via exposure and hazard assessment decisions is influenced by multiple scientific, technical, and social factors, including managing scientific uncertainty, technical decisions and capacity, and social, political, and economic influences from involved stakeholders. Assessments by multiple states and academic scientists suggest that EPA’s HA is not sufficiently protective. The ability of states to develop their own guideline levels and standards provides diverse risk assessment approaches as models for other state and federal regulators, while a sufficiently protective, scientifically sound, and enforceable federal standard would provide more consistent protection.

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This research was supported by the National Science Foundation (SES 1456897), the National Institute of Environmental Health Sciences of the National Institutes of Health (P42ES027706 and T32ES023679), California Breast Cancer Research Program (21UB-8100), and the Broad Reach Foundation. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Science Foundation, the National Institutes of Health, or other funders. We are grateful to individuals in state and federal regulatory offices who answered questions and provided documents during our research. We thank Cole Alder, Elizabeth Boxer, Walker Bruhn, and Amanda Hernandez for their research assistance, and the Editor and two anonymous Reviewers for their exceptionally helpful comments.

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  1. Department of Sociology, Whitman College, Walla Walla, WA, USA

    • Alissa Cordner
  2. Silent Spring Institute, Newton, MA, USA

    • Vanessa Y. De La Rosa
    • , Laurel A. Schaider
    •  & Ruthann A. Rudel
  3. Department of Sociology and Anthropology, Northeastern University, Boston, MA, USA

    • Vanessa Y. De La Rosa
    • , Lauren Richter
    •  & Phil Brown
  4. Department of Health Sciences, Northeastern University, Boston, MA, USA

    • Phil Brown


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Correspondence to Alissa Cordner.

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