Human and ecological risk assessment of toxic metals in sediment near coal mining dump yard and the pond receiving acid mine drainage

Abstract

ABSTRACT Soil and sediment pollution caused by toxic metals (TMs) is a widespread issue in many countries including India. However, there is a lack of studies on health risk assessment of TMs in sediment near coal mining areas in India. The present study analyses the pollution levels, ecological and human health risks of TMs such as Fe, Mn, Cr, Co, Cu, Cd, Ni, Zn, and Pb. The results indicate that the concentration of TMs in the sediment is higher than the reference soils. Pollution indices showed that Cr, Co, Cd, Pb, and Ni were significant pollutants, posing a potentially high ecological risk. The results of the health risk assessment indicate that the oral ingestion of sediment TMs is the primary exposure route, and the hazard index (HI) for children were higher than those for adults. While the non-carcinogenic risks for males and females were below the safe level (1.00), Pb and Cr contributed more to the HI (7.33) for children, indicating the existence of non-carcinogenic risk. Furthermore, Cd and Cr posed unacceptable carcinogenic risks for all groups, with children being more vulnerable to TMs than adults. The results of Principal Component analysis and Cluster analysis were well matched and supported the results of Pearson correlation analysis; the results revealed that Fe, Mn, Co, Cu, Ni, and Zn are from the same source, the coal mining, whereas Cd, Cr, and Pb came from multiple sources. The high pollution indices, ecological risk and carcinogenic risk underscore the urgent need for effective and sustainable remediation strategies.