Assessment of the concentration and environmental impacts of potential hazardous elements in coalfields in Northeastern Turkey

To investigate the impact of potential hazardous element (PHE) contamination on environmental and human health, the coaly shale, coal and shale coal outcrops of four sites, namely Ozyurt, Tarhanas, Kayadibi (Gümüşhane), and Manas (Bayburt), were selected as sampling areas for this study. The samples were analyzed using inductively coupled plasma (ICP) emission spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS) and a Rock–Eval 6 analyzer with a total organic carbon module. The enrichment factor (EF), potential ecological risk index (RI), and potential health risk index (HI) assessment models were used to evaluate the environmental and health risks in the vicinity of the coals. Results indicated that the mean concentrations of PHEs extensively changed and even exceeded the upper continental crust and world average values of low-rank coal concentrations. The assessment of the EF, RI and HI models revealed that the contamination levels of As, Hg, and Cd were higher than those of Pb, Co, Ni, V, and Mo. The evaluation of the EF revealed that the largest and lowest contamination levels of As, Hg, and Cd were observed in Ozyurt (29) and Kayadibi (1.8), Manas (9.6) and Kayadibi (1), and Kayadibi (5.6) and Tarhanas (1.9), respectively. A high-potential ecological risk was present in Ozyurt and Manas, whereas a considerable risk exists in Kayadibi and Tarhanas. The potential health risk values of As for children in Ozyurt, Tarhanas, and Manas and adults in Ozyurt were excessively high. This finding suggested the possibility of transferring the contamination from the coal, shale coal, and coaly shale outcrops