Sheep farming and the impact of environment on food safety

Sheep flocks are sensitive to the top soil intake, via their grazing activity and the ingestion of soil particles incorporated into the hay especially during harvesting operations. Such intake is estimated between 2 and 20% of the dry matter from grass and hay and may vary accounting for seasonal and geographical differences in the quality of pastures. The persistent organic pollutants accumulated in soil such as polychlorodibenzo-p-dioxins and -furans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (DL-PCBs), may transfer through the food chain. In this paper, the authors consider the quality of soils and the toxicokinetic factors that allow the transfer of the contamination to milk and the edible tissues in sheep. The wide range of PCDD/F concentration reported in milk (0.05-30 pg WHO1998-TEQ/g fat), meat (0.18-4.9 pg WHO1998-TEQ/g fat) and liver (4.8-161 pg WHO1998-TEQ/g fat) from extensively reared flocks in areas of European countries under different industrial and urban pressures, indicate the opportunity to adopt risk management options based on environmental quality standards and good agriculture practices, able to support the access to a safe and nutritious food. With respect to the PCDD/F and DL-PCB intake, liver represents the most contaminated food item, for its ability to bind such lipophilic contaminants irrespective of its lipid content. Case-studies from the Mediterranean area are illustrated, to support the environment and health approach also in terms of sustainability of family farms production.