An integrated approach towards groundwater quality and human health risk assessment in the Indo-Gangetic plains of West Bengal, India

Abstract

The escalating crisis emerging from overuse and pollution of groundwater is hitting India hard as the nation relies substantially on groundwater as a crucial freshwater resource. The lower Ganga Basin in West Bengal, India is a hotspot for arsenic and fluoride pollution in groundwater. This study assesses the lower Ganga basins’ groundwater quality in West Bengal, its characteristics and impact on human health, using a conglomeration of tools and techniques. The entire study area, covering 666 points, has been segregated into 10 sub-basins. As per EWQI analysis, 69% of the total points under study indicated excellent water quality whereas 9% showed very poor water quality with Arsenic concentration being the major factor influencing the groundwater quality followed by iron, nitrate and sulphate. The mean Total Health Index (THI) for infants, females, children and males was calculated to be 4.05, 2.21, 2.04 and 2.02 respectively depicting infants to be most susceptible to health hazards arising out of intake of polluted groundwater. Bhairabh-Jalangi emerged as the most polluted sub-basin as per EWQI as well as Health Risk Assessment (HRA). Uncertainties in HRA was quantified using Monte Carlo simulation wherein body weight (33.4%), ingestion rate (24.4%) and concentration of Arsenic (24.3%) were found to be the most significant health controlling variables in the sensitivity study. This study uniquely depicts sub-basin wise characterization of groundwater in the lower Ganga in WB and explores the effect of groundwater pollution on human health.