Bioaccumulation of perfluoroalkyl substances in a Lake Ontario food web

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals detected throughout the environment. To better understand the distribution of PFAS in an aquatic system (the Laurentian Great Lakes), stable isotope enrichment (delta C-13 and delta N-15), fatty acid (FA) profiles, and PFAS were measured in various species from the Lake Ontario (LO) aquatic food web. Sampled organisms included top predator fish, prey fish, and benthic and pelagic macroinvertebrates. The trophic level of each species in the LO food web was determined using delta N-15, and FA concentrations (range: <1-139 mg/g wet weight (ww)). The individual PFAS concentrations in the LO food web were similar to 1.5 to 5 times lower than previously reported. The highest PFAS concentrations were observed in deepwater sculpin (Myoxocephalus thompsonii, 150 +/- 35. 7 ng/g ww) suggesting a potential source of PFAS from the offshore benthic zone or sediment. The concentration of PFOS and long chain (C9-C14) perfluoroalkyl carboxylic acids (PFCAs) were significantly higher than short chain PFAS indicating the significant impact of hydrophobicity on the bioaccumulation of PFAS in organisms from the food web. However, high molecular weight PFCAs (>C8) did not exhibit increasing biomagnification factors (BMFs) and trophic magnification factors (TMFs) with log k(ow), suggesting hydrophobicity does not govern the movement of PFAS from low to high trophic levels in the LO food web. (C) 2021 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved.

Automated summary

This study investigated the distribution of PFAS in the Laurentian Great Lakes using stable isotope enrichment, fatty acid profiles, and PFAS measurement in various species. The results showed that PFAS concentrations in the studied organisms were lower than previously reported. Deepwater sculpin had the highest PFAS concentration, indicating a potential source of PFAS from the offshore benthic zone or sediment. The study also found that hydrophobicity significantly influenced the bioaccumulation of PFAS in the food web.