Exploring per- and polyfluoroalkyl substance distribution in Arctic wastewater treatment lagoons and natural wetlands: First record in Nunavik, Canada

Per- and polyfluoroalkyl substances (PFAS), as emerging and bioaccumulative contaminants, are widely present in water and wastewater systems. Municipal wastewater effluents serve as pathways for PFAS to enter aquatic environments. This study monitors the PFAS in wastewater treatment lagoons, nearby wetlands and bay in a Canadian Arctic community. Eight out of the 40 targeted PFAS were detected in samples collected from raw wastewater, wastewater treatment lagoons, natural wetlands, and Ungava bay. The total PFAS concentrations were in the ranges of 45.9-56.1 ng/L in wastewater treatment lagoons, 36.6-70.8 ng/L in natural wetlands and measured at 7.3 ng/L in the bay. The most prevalent and frequently detected PFAS were 6:2 FTS, PFHxA, and PFNA. At all sites, short-chain PFAS concentrations surpassed long-chain PFAS. Short-chain PFAS peaked at 267.01 ng/L (79.74%), while long-chain PFAS totaled 67.83 ng/L (20.26%). The estimated yearly mass flow rate of total PFAS into the environment through lagoon effluent was 2.33 g/year. The conducted environmental risk assessment for both the effluent of the wastewater treatment lagoons and the three downstream natural wetlands suggests that the risks associated with all PFAS under study posed minimal ecological risk, though long-term evaluation is needed. In conclusion, the findings of this research provide further information on PFAS pollution through wastewater in Arctic regions and may, as such, guide the development of comprehensive regulations to safeguard both human health and the environment, thereby mitigating potential future risks.