Polychlorinated biphenyls (PCBs) are highly persistent organic pollutants (POPs) that are still of concern, although they have been banned in Switzerland since 1986. Besides being toxic to humans and the environment, PCBs are easily dispersed, highly hydrophobic and thus bioaccumulate in our food chain. Therefore, the main PCB exposure route for humans is the consumption of food of animal origin that accounts in Switzerland for more than 90%, of which 70% is from bovine meat and dairy products.1 Apart from potential long-term adverse health effects, elevated PCB levels in animal products can also be accompanied with destruction of the livestock at the expense of the farmer. To address this problem, the aims of this project are i) the identification of a potential PCB entry pathway into food products, as well as ii) the assessment of the toxicokinetics of PCBs to improve risk management. Therefore, an in vivo experiment is currently conducted, in which mother cows are orally exposed over a long time period to a contaminated soil-grass silage mixture leading to a PCB exposure close to the feed maximum regulatory limit, while feeding their calves through milk. These experimental data will be used to assess the predictive ability of a dynamic model that incorporates the soil uptake from grazing and the PCB transfer from the mother cow to their suckling calf.2 The combination of in vivo and in silico will help to understand the accumulation process of PCBs in cattle, from which we can benefit to derive recommendations to further mitigate PCB levels and improve food safety.
