Environmental Contamination by Heavy Metals in Region with Previous Mining Activity

Due to its status as one of the most contaminated regions in Slovakia, 45 soil and plant samples were collected in the Middle Spis region. In soil, the exchangeable soil reaction, humus content and heavy metals content (Zn, Cd, Cu, Pb, Hg) were determined. Total content of heavy metals (TC-HMs) and content of mobile forms (MF-HMs) in soil, as well as metal content in plants, were determined by atomic absorption spectrometry. The concentration ranges for total Zn, Cd, Cu, Pb and Hg in soil were 33.1-953, 0.65-6.73, 11.0-913, 26.5-165 and 0.28--415 mg/kg, respectively. The overall concentration ranges of these metals in plants of two types (Athyrium filix-femina L. and Poaceae herbs) were 12.4-158.6, 0.10-1.63, 3.34-85.7, 0.09-29.7 and 0.01-12.8 mg/kg, respectively. Despite the values of Zn, Cd, Cu, Pb and Hg content in the soil exceeding limit values, only the Hg content in plants presented an ecological risk.