Evaluating contamination of seafood purchased from U.S. retail stores by persistent environmental pollutants, pesticides and veterinary drugs

Authors: BEDI, MEGHA - University Of Pittsburgh; Sapozhnikova, Yelena; NG, CARLA - University Of Pittsburgh

Submitted to: Food Additives & Contaminants. Part A: Chemistry, Analysis, Control, Exposure & Risk Assessment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2024
Publication Date: 2/5/2024
Citation: Bedi, M., Sapozhnikova, Y.V., Ng, C. 2024. Evaluating contamination of seafood purchased from U.S. retail stores by persistent environmental pollutants, pesticides and veterinary drugs. Food Additives & Contaminants. Part A. 41(3). https://doi.org/10.1080/19440049.2024.2310128.
DOI: https://doi.org/10.1080/19440049.2024.2310128

Interpretive Summary: The presence of chemical contaminants in food and the associated risks to human health have been reported, but relatively little attention has focused on commercially available seafood in the US. In this study, we tested seafood samples purchased from various retail stores in Pennsylvania for 445 chemical contaminants, including pesticides, veterinary drugs and environmental contaminants. Half of the seafood samples tested positive for at least one chemical residue, although at low levels. Measured levels of all detected veterinary drugs and pesticide residues were in compliance with the US and Canadian maximum residue limits (MRLs) . However, toxic equivalency quotient (TEQ) for the sum of detected dioxin-like polychlorinated biphenyls (PCBs) in catfish was almost 100-fold higher than the World Health Organization limits, suggesting that the tested catfish may not be safe for regular consumption.

Technical Abstract: Background: The presence of pollutant residues in food and the associated risks to human health have been reported, but relatively little attention has focused on commercially available seafood in the US. Objective: This study measured levels of legacy and current use veterinary drugs, pesticides, and environmental contaminants (PBDEs, PAHs, and PCBs) in seafood to improve understanding of foodborne exposure to toxic contaminants and identify vulnerable populations potentially at greater risk of exposure. Methods: 46 seafood samples were processed using QuEChERSER extraction and analyzed for 440+ analytes using low-pressure gas chromatography-tandem mass spectrometry (LPGC-MS/MS) and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) platforms. Risk assessment was performed based on maximum residue limits (MRLs), toxic equivalence (TEQ), estimated daily intakes (EDI), and hazard quotients (HQ). Results: Of the 445 analytes, 17 were detected at low frequencies; 50% of the samples tested positive for at least one chemical residue. The total concentrations of detected analytes ranged from non-detectable to 156 µg/kg wet weight. Considering individual veterinary drugs and pesticide residues, no risks were associated with the selected species. However, the TEQ for the sum of detected dioxin-like PCBs (PCB126 and PCB 167) in one catfish sample was almost 100-fold higher than the WHO limits. This suggests that the analyzed catfish may not be safe for regular consumption specifically by vulnerable groups such as non-Hispanic Black populations. Significance: This study contributes to efforts to improve data availability on the occurrence of contaminants in seafood. Such data can also be used to feed into risk assessment models such as those designed to predict bioaccumulation and toxicity of chemical contaminants. In addition, we provide measurements of chemical levels in wild-caught commercial fish which are indicators of ecological health. Therefore, this study contributes to improving risk assessment from both public health and ecological health perspectives.