Occurrence, Spatial Distribution and Health Risk Assessment of Potentially Toxic Elements (PTEs) in Surface Water Resources, A Case Study in Hamedan, the West of Iran

Background: This study aimed to investigate the concentration of potentially toxic elements (PTEs) including iron (Fe), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) and determine their health risks, and evaluate the water quality of Abbas-Abad, Khako, Moradbeig Valley rivers and Ekbatan Dam inlets and bodies located in Hamadan, Iran. Methods: In spring 2019, the concentrations of PTEs in water samples collected from 61 stations were quantified using an inductively coupled plasma optical emission spectrometry device. Water quality was evaluated using heavy metal pollution index (HPI), heavy metal evaluation index (HEI), contamination degree , heavy metal toxicity load (HMTL), and environmental water quality index (EWQI) indices. Carcinogenic and non-carcinogenic risks were calculated using cancer risk (CR) and hazard index (HI), respectively. Results: It was found that the average concentration of Fe and Zn had a statistically significant difference (P   0.05). By comparing the metal concentration to the World Health Organization’s standard, the concentrations of all elements were below the permissible limit, except for Fe and Cd, in 4 and 5 sampling stations. The quality of water sources revealed a low level of PTE contamination in the studied surface water. According to the HI results, there was no apparent threat to the residents’ health. Based on the CR assessment results, the dermal absorption of PTEs for both age groups was classified as low-risk. However, ingestion of these elements was categorized as high-risk. Conclusion: Since Hamdan’s surface water sources are contaminated with PTEs, it is necessary to investigate effective management strategies for preserving the integrity and health of water resources.