Per- and polyfluoroalkyl substances (PFASs) contamination of groundwater in Canada: a (too) short review

Concerns over per- and polyfluoroalkyl substances (PFASs) contamination of water continue to grow as more PFASs are found in more places and related guideline concentrations generally decline. Reports on the occurrence of PFASs in groundwater from around the globe have been published in scientific journals for over two decades now. Much of this work originates from the United States, China, and European countries. In this review, we investigated the state of studies publishing data on PFAS concentrations in groundwater or identifying PFAS sources to groundwater in Canada. We found and report on only 11 studies in scientific journals (by mid-2024), and the majority of these had linkages (direct or collaborative research, funding, or other key support) to federal or provincial governments. Potential reasons behind there being so few studies are discussed. Additionally, we pose and examine four key questions that highlight areas needing greater investigation in Canada. These are: (1) What is the state of PFASs in groundwater-sourced drinking water across the country? (2) What are background PFASs concentrations for groundwater? (3) What is the prevalence and distribution of PFASs sources to groundwater and risk posed by them? 4. How important is groundwater transport of PFASs to surface waters and aquatic ecosystems?