Background: This study evaluates heavy metal contamination resulting from mining activities in the Aras River, with a focus on assessing human health risks, quantifying sediment metal concentrations, and identifying pollution sources through statistical analyses.
Methods: Surface sediment samples were collected from multiple sites along the Aras River on the Iran–Armenia border, particularly near mining operations and tailing dams, during August and December 2020. Twelve samples were obtained from upstream and downstream of the Agharak Mine tailing dams. Concentrations of As, Mo, Cr, Cu, Ni, Pb, Zn, Hg, Fe, and Al were measured using ICPOES to assess environmental and human health risks.
Results: The estimated Average Daily Dose (ADD) values for all heavy metals studied were below standard guidelines, with higher ingestion rates observed in children. The HQ values for exposure pathways were generally below 1, suggesting low risk, although the HI values for children suggested a potential non-cancer risk in the future. Nickel concentrations exceeded probable effect levels (PELs) in 84% of the samples, while Hg showed unique local sources and minimal correlations with other metals. Principal component analysis (PCA) identified two components, explaining 89.7% of the variance, with PC1 accounting for 50.08% and showing strong loadings for As, Zn, Pb, Cu, and Ni. The main limitation of this study was the small sample size, which may limit the generalizability of the results.
Conclusion: The results underscore the importance of closely monitoring and effectively controlling heavy metal contamination in the Aras River to safeguard the ecosystem and human well-being.