Fluorochemicals in AFFF-contaminated sites: environmental fate, toxicity and treatment

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The use of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in decades has led to widespread contamination in humans, wildlife and the environment. Some PFAS are extremely persistent in the environment and exhibit high bioaccumulation potential and toxicity. The most severe form of this pollution is primarily associated with the use of PFAS-based aqueous film-forming foams (AFFFs) for firefighting activities, impacting groundwater, surface water, soil and sediment in several hundred federal contaminated sites across Canada. As the state of AFFF contamination has not been specifically investigated, regulatory frameworks for managing AFFF-contaminated sites largely do not exist. Unique physical, chemical and biological properties of PFAS pose great challenges for addressing the issue. Regulatory bodies and environmental consultants are asking: what types of PFAS are present in AFFF-impacted sites and what concentrations pose risks to the environment? How do PFAS transport and transform under varying natural and engineered conditions and in the presence of other contaminants? What cost-effective risk migration technologies can be implemented? Our research is aimed at answering these questions through detailed characterization of field contaminated samples, laboratory studies on the environmental fate and behaviours of PFAS in soil and groundwater systems, evaluating bioaccumulation potential of major PFAS, and developing an innovative nanotechnology-based remediation approach for PFAS removal. The research will be conducted by a group of internationally recognized researchers with complementary expertise in environmental engineering, chemistry and microbiology, and ecotoxicology. Results from our research will help environmental regulators and risk assessment experts develop policies, regulations or guidelines on AFFF use, disposal, risk assessment and remediation. The proposed research has important economic benefits to Canada by optimizing resources to reach risk mitigation goals cost-effectively and by enhancing technical expertise in the private sector in the area of environmental risk assessment and remediation.