Geochemical evaluation and human health risk assessment of nitrate-contaminated groundwater in an industrial area of South India

The primary goal of this study is to evaluate the groundwater quality and conduct a non-carcinogenic risk assessment of nitrate contamination in an industrialized and high-density region of South India. A total of 40 sampling sites were identified in and around the industrial area, and samples were collected during the pre-monsoon and post-monsoon seasons. Piper and Gibbs’ diagram shows that rock-water interaction, lithological characteristics and ion-exchange processes are the primary factors determining groundwater quality. The novel entropy water quality index (EWQI) indicated that 32 and 37.5% of the water in the study area were unsuitable for drinking purposes during both the pre-monsoon and post-monsoon seasons, respectively. Due to landfill leachate and modern agricultural activity, the nitrate concentration in groundwater post-monsoon had increased by 17.11%. The nitrate pollution index (NPI) value of groundwater exceeded the contaminated level by 22.77%. The non-carcinogenic human health risk assessment revealed that 35 and 40% of adult males, 37.5 and 52.5% of adult females and 42.5 and 55% of children during the pre-monsoon and post-monsoon periods were exposed to an increased concentration of nitrate in groundwater. The non-carcinogenic risk level to the exposed population in the study region descends in the following order: children > > females > males. The study suggests that low body weight in children is a direct result of consumption of low-quality water and that adult men and women suffer less severe consequences.