Generic Methodology to Prevent Food Contamination by Soil Born Pops in Free Range Livestock

Control of POP presence in feed for animals and food of animal origin is usually included in governmental monitoring, and many countries defined maximum residue levels (MRLs), which established a maximum tolerable concentration of POPs, which has shown not to endanger human health. However, such MRLs do not cover the POPs presence in soil, which could have much higher concentrations compared to feed due to its strong affinity and persistence of these contaminants in comparison to other environmental matrices. In addition, daily soil ingestion could lead to high transfer of soil borne POPs to livestock which lets suppose a high bioavailability of these compounds in soil. In this context, the goal of this study was to develop and to test an approach to evaluate the tolerable POP concentration in soil for different livestock animals in different rearing systems, allowing the safety of the produced food of animal origin. Therefore, we summarize existing knowledge about the risk of POP transfer in different livestock breeding systems via soil exposure and modelize via a backward calculation from the MRLs the corresponding and tolerable amount of POPs, which may be ingested by the animals in the considered rearing system.