Potentially toxic metal concentration, spatial distribution, and health risk assessment in drinking groundwater resources of southeast Iran

[Display omitted] •Potentially toxic metals detected in drinking groundwater resources.•More than 99% and 23.46% of the study area polluted by As and Pb.•High non-carcinogenic and cancer risk estimated for As in probabilistic approach.•Pollutant concentration was the most sensitive factor for health risk assessment. In this study, the concentration and spatial distribution of potentially toxic metals (PTMs), including arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), iron (Fe), manganese (Mn), and magnesium (Mg) in 23 wells and drinking groundwater distribution networks of Rafsanjan, located in southeast Iran were evaluated. Moreover, the assessment of carcinogenic and non-carcinogenic risks was estimated by Monte Carlo simulation (MCS). The results showed that the concentrations of As and Pb in more than 99% and 23.46% of the study area, respectively, were higher than the maximum concentration level (10 µg/L). The mean concentration of other metals, including Cd, Cr, Cu, Fe, Mg, and Mn in all drinking water resources was within the WHO standard level. The mean hazard quotient (HQ) for As in the age group of children was 9.246 and adults 2.972, indicating high non-carcinogenic risk of As in the study area. The lifetime cancer risk (LTCR) of As was 1.36E−3 for adults and 1.52E−2 for children, indicating high non-carcinogenic risk of As. The level of HQ and LTCR for Pb in both age groups was in the acceptable range. The results of sensitivity analysis showed that the most effective variables were pollutant concentration and body weight (BW), respectively. Finally, it can be concluded that exposure to PTMs, especially As through drinking water in the study area can have significant effects on people’s health living in the area; therefore, it is necessary to treat and remove As from groundwater resources before drinking or using for domestic purpose.