Per- and polyfluoroalkyl substances (PFAS) measured in seafood from a cross-section of retail stores in the United States

Authors: BEDI, MEGHA - University Of Pittsburgh; Sapozhnikova, Yelena; TAYLOR, RAEGYN - Oak Ridge Institute For Science And Education (ORISE); NG, CARLA - University Of Pittsburgh

Submitted to: Journal of Hazardous Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2023
Publication Date: 7/13/2023
Citation: Bedi, M., Sapozhnikova, Y.V., Taylor, R., Ng, C. 2023. Per- and polyfluoroalkyl substances (PFAS) measured in seafood from a cross-section of retail stores in the United States. Journal of Hazardous Materials. 459. https://doi.org/10.1016/j.jhazmat.2023.132062.
DOI: https://doi.org/10.1016/j.jhazmat.2023.132062

Interpretive Summary: Seafood is considered a dominant dietary source of human exposure to per- and polyfluoroalkyl substances (PFAS), also known as forever chemicals. In this study we investigated the levels of PFAS in seafood from retail stores in Pittsburgh, PA, USA. Low ng/g levels of PFAS were found. Tolerable weekly intakes (TWI) established by the European Food Safety Authority (EFSA) were calculated for select PFAS, and based on average consumption levels, were below the established levels. From a seafood consumer’s perspective, we did not find any evidence to support the hypothesis that shopping habits/choices impact exposures, which may alleviate concerns about disparities associated with location, accessibility, or affordability of certain seafoods.

Technical Abstract: BACKGROUND: Seafood is a dominant non-occupational source of human exposure to per- and polyfluoroalkyl substances (PFAS). Existing studies on foodborne PFAS exposure have focused on only a subset of these compounds. The impact of consumer choice on exposure has not yet been explored. OBJECTIVES: We quantified the levels of PFAS in seafood from retail stores and investigated whether consumer choices surrounding stores, seafood type, or husbandry (e.g. farmed vs. wild) impact exposures. METHODS: 46 seafood samples were processed using QuEChERSER extraction and analyzed for 33 PFAS using both liquid chromatography-high resolution mass spectrometry (LC-HRMS) and LC-triple quadrupole platforms. We built exposure estimates from measured levels and compared them to tolerable weekly intakes (TWI) established by the European Food Safety Authority (EFSA). RESULTS: Low levels of PFAS were detected in 34 of the 46 samples. Total PFAS ranged between 0.12 to 20 ng/g wet weight with highest levels measured in Estonia-sourced smelt. PFHxS was the most abundant compound, detected in 59% of the samples. Highest median levels were of PFOA (0.84 ng/g) with elevated concentrations found in China and Vietnam-sourced clams (2.4 and 1.6 ng/g respectively). No statistical difference was found between stores, origins, and production methods (farmed and wild-caught). Exposure estimates were below the TWI for an average daily consumption of 18 g of seafood. However, for larger portion sizes (50-170 g), exposures were above the TWI for >1 meal/week of flounder, >3 meals/week each of catfish and cod, and >4 meals/week of salmon. DISCUSSION: Based on average consumption levels, analyzed seafood was below TWI for PFAS. However, for populations that consume more seafood, exposures may reach thresholds. Seafood surveys could provide better insight into exposures of vulnerable populations. Consumer choice is unlikely to substantially impact PFAS exposures for these types of seafood, highlighting the global nature of PFAS contamination.