HEAVY METALS IN MIDDLE NITRA RIVERSIDE

Abstract

Present state of environment is widely affected by various impacts of man which significantly eliminate negative affecting of its influence on the environment. In the past this fact was not so implemented and thus there was uncontrolled escape of contaminants of organic, but also inorganic origin into various components of environment. The most sensitive component is water ecosystem and its close plates (base sediments, banks sediments and biosphere near the flows).
River Nitra ranks among the most affected water ecosystems in SR that was in 1965 the recipient of sludge, that was by accident in Zemianske Kostoľany uncontrolled spilled into the river with aftermath of long-term contamination of all sub-components in ecosystem, mainly by heavy metals (Hg, As, Pb, etc.).
Soil contamination by Cd and Hg was analytically confirmed. The contents of these risk elements in soil extract of aqua regia 1.85 - 3.7 fold (Cd) and 4.57- 36.3 fold (Hg) exceeded the limit values (0.4 mg.kg-1 and 0.15 mg.kg-1 respectively) given by the legislative. Other metals exceeding limit values were lead (1.064 - 1.072 fold), zinc (1.096 - 1.192 fold) and chromium (1.172 – 1.644 fold).
From assessed soil content of heavy metals only bioavailable forms of Pb determined in soil extract by NH4NO3 2.0 - 3.3 fold exceeded the limit value 0.1 mg.kg-1.