CONTAMINATION OF FLUVISOLS ON LABE FLOODP LAINS BY HAZARDOUS ELEMENTS

The content of hazardous elements and organic xenobiotic compounds alo ng the water streams of the Labe catchment area (mainly along the prop er Labe river basin) has been investigated in three geomorphologic ele ments. in fluvisols of the innundation zone, in the floodplain fluviso ls of higher terraces and in the neighbouring zonal soils. The compari son of the values of hazardous elements is presented in the Tabs I to III and in the Figs 1 to 3. The highest loads have been found in the i nnundation zone. Downstream the industrial cities have not only the ex ceeding amount of contamination limit for Cd, Hg, Zn, Cu, Pb, Cr, but even the excess of the maximal admissible values of Cd, Hg, locally Zn , Cu, Cr is mostly found. This is a seldom case of soil intoxication, which is not encountered even in the most expressive immission areas ( except for the vicinity of metallurgic plants). The innundated fluviso ls are generally contaminated (in the sense of excess of the upper bac kground levels) by the above-mentioned elements. They are characterize d by an elevated solubility of hazardous elements (Cr, Cu, Zn) in the 2M HNO3. The fluvisols of the higher geomorphologic floodplain element s as compared with zonal soils exceed also very often the contaminatio n limits in order Cd, Zn > Cu (As) > Pb (Cr). The results of the inves tigations of organic xenobiotic compounds are presented in Tabs IV and V and Figs 4 and 5. Innundated fluvisols are characterized by maximal soil contamination (exceeding the background levels of soils in immis sion-free areas) by all PAU except of chrysen. Also elevated concentra tion of mononuclear aromatic hydrocarbons, PCB and HCB occurs in innun dated fluvisols, mainly in the upper stream area of Labe in CR. The di fference between the contamination of the higher river terraces and zo nal soils with organic pollutants is less pronounced than by hazardous elements. The dependence of the contamination of fluvisols by both th e hazardeous elements and organic xenobiotic compounds upon their geog raphical position along the river to industrial cities is graphically presented in Figs 2, 3 and 5.