Soil pollutions can accumulate in the food chain. The concentrations in an organism can increase as the organism is ranked in the food chain. A substance in the soil can be ingested by a worm, which is then consumed by a mole, which in turn eaten by a bird of prey. Although the bird of prey does not come in direct contact with the soil, it can experience effects by the pollution through its food. RIVM describes in this report the models that can be used to assess secondary poisoning and describes the practical experiences, the obstacles and possible solutions.
There are two routes to take account of secondary poisoning: firstly in standard setting (policy) of substances and secondly in the risk assessment of substances at a contaminated site. For the risk assessment of substances at a site, the risk of a secondary poisoning in the food chain is assessed by individual experts. For this, different calculation models are available, such BERISP, OMEGA 6.0 and SEDIAS. A commonly proposed request in practice is an unambiguous method to evaluate secondary poisoning.
This report also describes for which substances in current standards secondary poisoning has been taken into account. Until 2008, when the soil quality standards were introduced in the Soil Quality Decree, it was not customary to take secondary poisoning into account for standard setting for soil contamination. For a number of substances (including the pesticides aldrin, dieldrin and endrin and DDT, DDD and DDE) standards are currently being evaluated, taking into account secondary poisoning.