The National Atmospheric Deposition Program (NADP) National Trends Network (NTN), a Premier Model of Multi-Sector Partnerships, Working to Provide New Information on PFAS Deposition in Precipitation

Public and Private Environmental/ Public Health Laboratory Partnerships
Oral Presentation

Prepared by M. Shafer, M. Olson, J. Schauer
University of Wisconsin, State Laboratory of Hygiene, 2601 Agriculture Drive, Madison, WI, 53718, United States

Contact Information: [email protected]; 608 217 7500


Environmental contamination with perfluorinated alkyl substances (PFAS) has developed into one of this nation’s most significant environmental public health problems. Potential sources of human exposure to PFAS are poorly characterized for large segments of the U.S. population, particularly in rural communities. Human exposure to PFAS in rural and agricultural America may occur via sources and mechanisms common to residents of urban environments (e.g., exposure to consumer and personal care products), however, rural populaces, especially those who reside on or near agricultural operations, may be exposed via a suite of distinctive sources, including groundwater, soil, and dust. Many of these sources are directly linked to atmospheric deposition of PFAS.

There is only limited knowledge of the atmospheric transport and fate of PFAS compounds, precursors, and potential transformation products. The presence of PFAS in precipitation, including our recent measurements in National Atmospheric Deposition Program National Trends Network (NADP NTN) samples, indicates that precipitation is an important contributor to surface and groundwater contamination and may therefore represent a significant human exposure vector. The Wisconsin State Laboratory of Hygiene (WSLH), Wisconsin’s primary public health laboratory, was ideally positioned to assess the efficacy of the NADP-NTN network to provide precipitation data for PFAS. The WSLH operates the NADP program, our nation’s foremost long-term monitoring program of atmospheric chemistry, and processes samples from over 260 monitoring sites on a weekly basis. The NADP-NTN network is a premier model of multi-sector partnerships and cooperative effort, comprising over 110 federal, state, tribal and local governmental agencies, educational institutions, private companies and NGOs.

In this pilot study we performed PFAS measurements on precipitation samples from 34 sites across the nation, and in parallel conducted laboratory and field experiments designed to examine whether the NTN could support a national PFAS sampling program. Samples were analyzed for 36 PFAS compounds and dedicated experiments addressed systems blanks and stability/losses of the PFAS species in the NTN precipitation collectors. Concentrations of the detectable PFAS species were low, generally less than 1 ng/L, though the sum of PFAS species exceeded 4 ng/L at several sites. PFNA was the most frequently detected species, closely followed by PFOS and PFOA The presentation will focus on outcomes of the monitoring network evaluation and address the role of multi-sector partnerships (like NADP) in environmental health protection.