A method is proposed for the assessment of the interactive accumulation of heavy metals in soils. Sixty surface soil samples were collected from fifteen sites, at a depth of 0-30cm, evenly distributed, within the 30,700ha comprising the study area.
It was found that at least some of these metals were significantly contributed to soil, i.e. Mn 9.53, Fe 8.06, Zn 0.86, Pb 0.29, Cd 0.033, Co 0.112 and Ni 0.125 kg/ha, respectively.
Similarly considerable levels of plant nutrients were accumulated in the studied soil such as P2O5 8.6, or 3.75 kg P/ha, K2O 52.92 or 43.94 kg K/ha, and Ca 78.98 kg/ha. As expected, the heavy metals accumulated in lower concentrations than those of plant nutrients and in non toxic levels. Nevertheless, the toxicity of these metals must be considered in relation to long term accumulation.
It was shown that the proposed method, based on the quantification of the elemental interactions contribution in heavy metals, could be used as a tool for the quantitative assessment of their accumulation and for the prediction of the «silent pollution» that gradually occurs in soils with these metals.