Former EPA, NIEHS directors criticize WHO’s draft PFAS drinking water guidance

Former directors of the National Institute of Environmental Health Science (NIEHS) and of the U.S. EPA’s Office of Science and Technology have criticized the World Health Organization’s draft drinking water guidance for two per- and polyfluoroalkyl substances (PFAS), according to a press release from the Green Science Policy Institute.

The directors, Betsy Southerland and Linda Birnbaum, claim the draft guidance exhibits a “striking and inappropriate disregard of the best available science,” and they recommend the guidelines be extensively revised to protect public health, as published in their viewpoint in Environmental Science & Technology.

WHO’s draft recommends a limit of 100 ppt for PFOS and PFOA in drinking water — a level 25 times higher than that recently proposed by the U.S. EPA.

The press release claims that the discrepancy between the two agencies’ guidelines is largely because WHO eschewed calculating health-based values in favor of technology-based values. As a result, WHO’s draft ignores the large body of human and animal health studies to focus on remediation technology capabilities and costs. The authors also argue that the draft’s technological basis appeared to be “arbitrary” with no specific evidence that these levels are the lowest that can be reliably achieved.

The viewpoint comes nearly six months after more than 100 scientists sent a letter to the WHO urging a complete overhaul or withdrawal of the draft guidance and requesting disclosure of its authorship and potential conflicts of interest.