Toxicokinetic modelling of the transfer of non-dioxin like polychlorinated biphenyls from feed into edible tissues of pigs

• Published in: The Science of the total environment 2023-09, Vol.892, p.164539-164539, Article 164539
• Main Authors: Moenning, Jan-Louis, Ohlhoff, Britta, Yamamoto, Mariko, Jährmann, Anke, Jahnke, Anne, Lüth, Anja, Pieper, Robert, Numata, Jorge
• Format: Article
• Language: English
• Subjects: animal growth; animal-based foods; environment; excretion; feed contamination; Food safety; half life; health effects assessments; human health; humans; liver; muscles; PBTK; Pharmacokinetics; polychlorinated biphenyls; pork; Sus scrofa domesticus; swine
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.164539

Non-dioxin-like polychlorinated biphenyls (ndl-PCBs) are persistent environmental pollutants that accumulate in the tissues of exposed animals and humans. Contaminated feed can lead to ndl-PCB contaminated food of animal origin; such foods are the main route of human exposure. Therefore, predicting ndl-PCB transfer from feed into animal products is important for human health risk assessment. Here, we developed a physiologically based toxicokinetic model describing the transfer of PCBs-28, 52, 101, 138, 153 and 180 from contaminated feed into the liver and fat of fattening pigs. The model is based on a feeding study with fattening pigs (PIC hybrids) that were temporarily fed contaminated feed containing known concentrations of ndl-PCBs. Animals were slaughtered at different ages, and ndl-PCB concentrations in muscle fat and liver were determined. The model accounts for animal growth and excretion via the liver. Based on their elimination speed and half-lives, they can be categorized into fast (PCB-28), intermediate (PCBs 52 and 101) and slow (PCBs 138, 153 and 180). Using a simulation with realistic growth and feeding patterns, the following transfer rates were found: 10 % (for fast), 35–39 % (intermediate) and 71–77 % (slow eliminated congeners). Using the models, the highest level of 3.8 μg/kg dry matter (DM) was calculated for any sum of ndl-PCBs in pig feed to ensure that the current maximum levels in pork meat and liver (40 ng/g fat) are not be exceeded. The model is included in the Supplementary Material. [Display omitted] •Elimination speed of 6 ndl-PCBs decreases with time due to increased fat fraction.•Elimination classified: fast (PCB-28), intermediate (52, 101), slow (138, 153, 180).•Transfer rates of 10 % (fast), 35–39 % (intermediate) and 71–77 % (slow) identified