Source-specific probabilistic health risk assessment of potentially toxic elements in groundwater of a copper mining and smelter area

Abstract

The occurrence of potentially toxic elements (PTEs), including twelve heavy metal(loid)s (Cd, Cr, Cu, Ni, Pb, Zn, Hg, As, Co, V, Fe, Mn), fluoride (F−), and nitrate (NO3−) was evaluated in groundwater in the copper mining and smelter area of Bor city (south Carpathian, eastern Serbia). Groundwater samples were analyzed to determine the extent of pollution, identify natural and anthropogenic input of PTEs, and estimate potential human health risks due to exposure to these substances. The results revealed that the groundwater in the study area was highly contaminated with PTEs, particularly Cu and Zn. Multivariate analysis supported the natural and anthropogenic origin of PTEs, with Fe, Mn, and F− classified as naturally occurring, NO3− resulting from agricultural activities, while other PTEs were linked to smelter/mining processes. Geospatial mapping discovered several hotspots with potential high non-cancer and cancer risks to humans through ingestion pathway. From the studied PTEs, As is the most health risk contributing toxic element. The source-specific probabilistic risk assessment indicated the most significant contribution to the hazard index and total cancer risk from accidental leakage of metallurgical wastewater and wastewater from open mine pits. Monte Carlo analysis identified the human body weight and the ingestion rate as the most sensitive risk parameters. The study underscores the need for stringent environmental management measures, emphasizing the critical role of source-specific risk assessments in mitigating potential hazards associated with metallurgical wastewater and open mine pits.