Assessment of limit values of risk elements and persistent organic pollutants in soil for Czech legislation

The proposal of hierarchical limit system of risk elements (RE) and persistent organic pollutants (POPs) for agricultural soils is presented. The system is not proposed for forest soils (limits are still missing in the Czech Republic). Two levels of limit values were proposed. The first one is the prevention limit statistically derived from the background values of RE and POPs in Czech agricultural soils. The second one is indication limit derived from the risk of plant growth inhibition (RE phytotoxicity effects where the results of experimental trials were utilised), the risk of food chain contamination (RE transfer from the soil into the plants where the results of experimental trials testing the transfer of RE from soils into plants were used) and human health risks (RE and POPs inhalation, dermal and oral intake where the model following US EPA methodology was calculated). The limit values system should replace current version of legislative norm - Decree No. 13/1994 Coll. The principles of limit values assessment for individual levels of the limits are described.