PROPOSAL OF SOIL CONTAMINATION LIMITS FOR POTENTIALLY HAZARDOUS TRACE-ELEMENTS IN THE CZECH-REPUBLIC

The contamination limits (reference values) for As, Be, Cd, Co, Cr, Cu , Hg, Mn, Mo, Ni, Pb, V and Zn have been derived, based on the evaluat ion of the background levels of the trace elements in 13 soil-litholog ical groups. The significant differences in total concentrations along with the solubility in the 2M HNO3 (Tabs I, II) and the evaluation of the upper limits of the variability (GM.GD(2), percentiles) of the in vestigated sets led to the derivation of the soil contamination limits . The exceeding of the reference values indicates the increased anthro pogenic inputs into the soils. The contamination limits (in the sense of the upper natural background levels) have been derived both for the total contents (Tab. III) and the contents in the cold 2M HNO3 (Tab. IV). The lithological differentiation in the proposals is reduced for pragmatic reasons. The system enables us also to use simplified mean r eference values or texturally differentiated values for the most sedim entary parent materials. The geogenic extremes are excluded (see only minimal values for Co, Cr, Cu, Mn, Ni, V in mafic rocks). Generally, a nthropogenically contaminated fluvisols have to be evaluated like othe r soils. The proposed concept of contamination limits is very similar to some reference values assessing the suspicion of contamination of A ustrian and German authors.