CONTAMINATION OF FEED CROPS AND CEREAL-GRAINS IN THE NORTH-BOHEMIAN IMMISSIONS IMPACT REGION

The contamination of feed crops and cereal grains was investigated in the north-Bohemian region, characterized by severe immissions. It was found out that neither the feed crops nor the grains of cereals are co ntaminated in such a degree to exceed the fixed sanitary limits. A mor e expressed contamination does not occur even in the areas with the mo st severe immission impacts. Only a slight trend of relative enrichmen t of the feeds phytomass by As, Be, Cd, Cu, Hg and Zn can be found in the districts Most, Teplice and partially in the district Usti nad Lab em, in accordance with the immission impacts. The immissions influence is very often combined with the uptake of Cd (Zn) from soils. The upt ake depends on the soil acidity and on the relative content of element s in the soil. But even in the most hazardous parts of the region the soil loading exceeds only the upper background levels (in an areal for m for Cd, As, Be) and seldom the limits for critical transfer into the food chain. Geochemically high contents of Cr and Ni in soil derived from, basalts are not reflected in their uptake by plants. The results are in accordance with the findings of the Research Institute for Ani mal Production. They proved that in the north-Bohemian region good qua lity feeds are produced. Negative impacts on animals are caused by the direct (inhalatory) influence of immissions.