THE EFFECT OF HEAVY METAL CONTAMINATION TO THE BIOLOGICAL AND CHEMICAL SOIL PROPERTIES IN MINING REGION OF MIDDLE SPIŠ (SLOVAKIA)

Despite the importance of mineral resources for the progress of humans, extraction of minerals has caused serious environmental problems. Contamination of soils by heavy metals in mining areas leads to the deterioration of soil quality and other environmental components. Removing of heavy metals from the soils is not easy, because they are non-biodegradable, and persistent in soils for tens or hundreds years. The aim of the study was to determine level of soil pollution by heavy metals in the surrounding of processing plant and find out the effect of heavy metals on enzyme activity and some chemical soil parameters. Total content of heavy metals (Cu, As, Cd, Pb, Zn), activity of soil urease, acid phosphatase, alkaline phosphatase, catalase, soil reaction, organic carbon and nutrients were determined. Heavy metals exhibit toxic effect on enzyme activities, what resulted as increasing soil enzyme activity with the decreasing heavy metal content. Significant positive correlation was found between heavy metals and some enzymes themselves. We found no statistically confirmed influence of heavy metals to the organic carbon, soil reaction and nutrients.