[Public health evaluation of (hazardous) substances in soil--concept of the AGU and Department of "Tolerable (Hazardous) Substance Concentrations in Soil" for metals].

Up to now no uniform procedure and no generally accepted values exist for health evaluation of pollutants in soil. Aim of the working group for environmental hygiene (AGU) of the Bavarian Ministry of Labour and Social Order, Family, Women and Health is to propose health-based procedures and values for assessment, in consideration of existing concepts and regulations. Basis for health evaluation is the existence of appropriate soil investigations. This refers to the sampling scheme (sampling depth, sampling site and manner, number and representativity of samples) as well as sample preparation and analysis. The "still tolerable pollutant concentration in soil" (TSKB) is supposed to mark a threshold which separates a range of tolerable pollutant concentration from a range where soil-related measures are indicated. Basis for determination of a TSKB-value is the estimation of the average uptake of the respective substance via air, drinking water and food. From this the average level of a tolerable dosis without health risk by regular long-term uptake by humans is calculated. From the remaining portion of tolerable uptake the TSKB-value for the additional pathway of uptake by soil is derived. The estimations are representatively performed for 3-year old children, because small children are especially endangered by uptake of polluted soil. TSKB-values were determined by this procedure for the metals As, Cd, Cr, Cu, Hg, Ni, Pb, Zn and compared with assessment criteria and values of other working groups.