Assessing the Ecological Risks and Spatial Distribution of Heavy Metal Contamination at Solid Waste Dumpsites

Soil samples from wild solid waste dumpsites were collected in the Bijeljina-Zvornik region (Republic of Srpska, Bosnia and Herzegovina), and the concentrations potentionally toxic metals (Ni, Cr, Mn, Zn, Cu, Pb, Cd, Fe and Al). The disposal of waste at wild dumpsites has emerged as a serious environmental challenge affecting both developed and developing countries. This paper aims to provide an in-depth analysis of the complex issue of wild dumpsites, focusing on the contamination of the environment with toxic metals. The improper disposal of solid waste has become a global concern, with wild dumpsites being a significant component of the problem. In accordance with national legislation, the mean values for Cd and Ni exceeded the limit values. Very strong positive correlations are observed between Zn and Cu, between Cd and Pb and between Ni and Cr. The ecological risk assessments for Mn are extremely high; for Ni and Pb, they are high; for Zn, Cu and Cr, they are appreciable; and for Cd, they are moderate. The Pollution Load Index (PLI) and Contamination Factor were used to evaluate metal pollution in soil samples. PLI values exceeding 1.0 in five samples signify soil pollution, supported by mean values indicating contamination. Research findings reveal different contamination levels, with Pb, Cr, Cu, and Zn at low levels, and Ni and Cd at moderate levels. The visualized results of ecological risk assessments for heavy metals in the soil underscore the critical importance of continuous monitoring and effective management of heavy metals at illegal dumpsites to preserve and protect surrounding ecosystems. The use of Surfer 12 software and the kriging method has proven to be an invaluable tool for exploring the spatial distribution of toxic metals in the study area.