Environmental Testing, Biomonitoring and Partnerships: A Public Health Intervention Story to Address PFAS Groundwater Contamination in Minnesota

Oral Presentation

Prepared by C. Huset1, J. Nelson2, J. Kelly3
1 - Minnesota Department of Health, Public Health Laboratory, 601 Robert Street N, Public Health Lab, St Paul, Minnesota, 55155, United States
2 - Minnesota Department of Health, Chronic Disease and Environmental Epidemiology, Golden Rule Building, 85 East Seventh Place, Suite 220, St Paul, Minnesota, 55101, United States
3 - Minnesota Department of Health, Environmental Health, 625 Robert Street N, P.O. Box 64975, St Paul, Minnesota, 55164-0975, United States

Contact Information: carin.huset@state.mn.us; 651-201-5329


Background: Perfluoroalkyl substances (PFAS) were discovered in private and municipal drinking water wells in groundwater testing in Washington County, Minnesota conducted by the Minnesota Department of Health (MDH) and the Minnesota Pollution Control Agency in 2004. The source of contamination was nearby waste disposal facilities. The initial PFAS of interest measured by MDH Public Health Laboratory (PHL) were perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS); five other PFAS including perfluorobutanoate are now routinely monitored. Public health interventions to reduce community exposure to PFAS through drinking water included installation of large-scale granular activated carbon filters at a water treatment plant and private wells, provision of bottled water and access to municipal water.
Methods: Using data gathered through environmental monitoring and agency expertise in laboratory methods, environmental science and epidemiology, MDH initiated a biomonitoring project in 2008. The project measured seven PFAS in serum of 196 long-term residents of the affected area to assess whether the interventions were effective at reducing PFAS exposures in the community. Two additional biomonitoring studies were conducted in 2010 and 2014 in the same population. In 2014, the project also included 156 residents who moved to the community post-interventions. PFAS analysis was conducted by MDH PHL using liquid chromatography tandem mass spectrometry.
Results: Serum concentrations of the three most common PFAS (perfluorohexanesulfonate, PFOS, PFOA) were higher than national background levels, but declined 34-59% between 2008-2014. This decrease is similar to what would be expected based on studies in other communities and estimated half-lives. Serum concentrations in the newer residents were similar to national background levels. These findings indicate that the interventions to reduce drinking water exposure to PFAS in this community were effective. The biomonitoring projects illustrate the value of collaboration in using environmental monitoring, laboratory and environmental science, and epidemiology to inform and develop sound biomonitoring science.