Risk communication and policy for emerging contaminants: The challenge of perfluorochemicals

Emerging contaminants present an added challenge for risk communication about exposures to toxic substances. When “what we don't know” looms much larger than “what we do know,” it is difficult to gain the trust and confidence of the communities we serve. Additionally, the lack of robust toxicological data can lead to temporary guidance numbers for evaluating levels of chemicals. These challenges arise out of limited toxicological knowledge and changes in health-based criteria that reflect advancing science, lack of understanding of environmental fate and transport, and ongoing site investigation. A current example of risk communication for emerging contaminants is groundwater contamination from perfluorochemicals (PFCs) in Washington County, Minnesota. An extensive program of groundwater sampling of public and private wells has found that concentrations of PFCs exceed MDH guidelines in more than 100 private wells, an industrial plant well, and some municipal wells. Measures to prevent or reduce exposure to PFCs include bottled water, whole house granular activated carbon (GAC) filters, a municipal GAC filter system and extension of municipal water service to new areas. This presentation will explore the challenges of risk communication for emerging contaminants and interim guidance through the example of PFCs, including:1.Preparing the target audience for continuing change and developments, 2.Consistent messaging in the context of changing science, 3.Helping the target audience see the measure of public health protection built into health based standards, 4.Collaboration between agencies as a powerful tool in fostering credibility and public confidence.