Hydro-geochemical evaluation and health risk assessment of groundwater in coastal regions: a case study of eastern Andhra Pradesh, South India

Hydro-geochemical investigation on the quality of groundwater in the coastal aquifer region of eastern AP, India, was chosen as a geochemical study for the selected region which was not evaluated before. Totally 82 coastal villages were selected, and 164 water samples from the ground were gathered for both pre- and post-monsoon seasons. The water quality index (WQI) of the analyzed samples revealed that around 73 and 76% of the study area come under the poor to unsuitable category during pre- and post-monsoon period, respectively. The major geochemical facies responsible for contamination, which are identified as mixed Ca-Mg-Cl >NaCl >Ca-HCO3> mixed Ca-Na-HCO3. The human health risk assessment studied using the United States Environmental Protection Agency (USEPA) model disclosed a higher average total hazard index of 2.17 and 2.32 for children when compared to adults (1.6 and 1.7). Apart from high salinity and hardness, HHRA results also unveil that the local community inclusive of both children and adults is vulnerable towards nitrate toxicity. Geochemical report extracted from Piper diagram and Chand’s plot shows a similar trend in accordance with the WQI. An account of the level of contaminants in the groundwater and the prominence of noncarcinogenic health risk in the study area against the standard norms are discussed in detail. These observations insist the measures be implemented against the varying environmental conditions during different monsoon seasons keeping in mind the vulnerability of nitrate toxicity. © 2021, Saudi Society for Geosciences.