Health risk assessment of heavy metals and predication of water quality indices with using Arc-GIS software: a case study of South Kerman Province

Abstract

ABSTRACT In many developing countries, including Iran, reservoirs have become essential for providing potable water. This study focused on 20 sample reservoirs in the southern Kerman province, specifically assessing heavy metal contamination. The primary objectives of this research were to determine the concentrations of hazardous heavy metals, such as As, Cr, Pb, and Ni, in the water, and to conduct a Health Risk assessment. The sample preparation process followed the guidelines outlined in the 21st edition of Standard Methods, with reference number A3120. Alarmingly, the average levels of most heavy metals in these reservoirs exceeded the drinking water standards set by both the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA). To evaluate water quality, the Water Quality Index (WQI) was employed. Based on this assessment, the water resources in Faryab and Qalaganj were deemed excellent for drinking, while those in Jiroft were classified as good. Furthermore, the findings from the Hazardous Materials Potential Index (HMPI), Heavy Metal Evaluation Index (HMEI), and Extended Water Quality Index (EWQI) were consistent with the trends observed in the WQI. Among these locations, Jiroft had the highest average WQI, scoring 62.5, followed by Faryab and Qalaganj with WQIs of 32.5 and 31.5, respectively. The Total Hazard Quotient (HI) for the metals in the urban drinking water samples from Qalaganj, Jiroft, and Faryab exceeded 1, with values of 5.06, 4.9, and 4.4, respectively. This indicates potential harm to both adults and children. The highest Cancer Risk (CR) values, specifically 3.3 × 10−2, were observed in Jiroft for children exposed to the water dermally, while the lowest levels were found in Faryab among adults exposed to Pb through their skin. In all examined locations, the cumulative cancer risk suggests a medium to extremely high risk. These findings underscore the importance of implementing corrective measures to enhance the quality of drinking water resources.