Spatio-Temporal Assessment of Groundwater Quality and Human Health Risk: A Case Study in Gopalganj, Bangladesh

A set of hydrochemical analysis, drinking water evaluation indices along with multivariate statistics and geostatistical model are applied to evaluate the groundwater quality of Gopalganj District, Bangladesh. A total of 46 groundwater samples are analyzed for the pre and postmonsoon seasons to assess the possible consumptive human health risk among the adults and children of the study area. It is found that most of the studied hydrochemical parameters (pH, EC, TDS, Na + , Cl − , HCO 3 − , CO 3 − , As, Mn, Fe, B, NO 3 − , etc.) exceeded the limits stipulated by different standards for drinking water. From multivariate statistical analysis, high-salinity characteristic of groundwater resulting from seawater intrusion is observed. Spatial extensions of EC, Cl − , As, Fe, and Mn vary significantly around the study area. Strong, moderate, and weak spatial dependences are found for both seasons. The exponential semivariogram model is found to be dominant when considering the best-fit model analyzed for both seasons. In addition, mean Hazard Quotient and Hazard Index values based on As, Fe, Mn, B, NO 3 − , and F − imply that the groundwater poses substantial health risk for both adults and children and fluctuates in accordance with seasonal variation. The carcinogenic risk among adults and children due to As is high in the study area during both seasons. The groundwater of the study area was characterized by high salinity possessing high level of noncarcinogenic as well as cancer-risk (As) vulnerability of the local community.