Health risk assessment of heavy metal pollution using water quality indices and Monte Carlo simulation in Babol underground water

Abstract

Due to population growth, agricultural development, and industrialization worldwide, the quality of groundwater resources is declining. This study assessed heavy metal contamination using quality indicators in rural drinking water in Babol, Iran (2022): pollution index (Cd), heavy metal pollution index (HPI), heavy metal evaluation index, and heavy metal index (MI), as well as risk assessment using deterministic and probabilistic methods for populations at risk. In this descriptive cross-sectional study, 60 groundwater samples were collected from 30 stations in the dry and wet seasons. The results showed that the concentration of iron (Fe) shows the highest average concentration, followed by zinc (Zn) and copper (Cu). During the wet season, the HPI showed high and moderate contamination in 6.6 and 93.4% of the areas, respectively. The results of the MI values showed that 23.3 and 40% of the areas were undrinkable in the dry and wet seasons. Hazard quotient index was calculated in the order Cr > Cu > Pb > Fe > Zn > Mn > Cd in three age groups (men, women, and children). The highest and lowest carcinogenic risk values were for Pb (3.03 × 10−2) in the children group and Cd (8.7 × 10−7) in the women group, respectively. Analyzing the results, we see that the excess lifetime cancer risk (ELCR) values for total heavy metals (Pb, Cr, and Cd) and all three age groups are generally very low. The results of the Monte Carlo simulation are presented. The highest ELCR of heavy metals in water in the women's group is 0.0309.