Groundwater contamination and human health risk assessment of drinking water in Kaliganj Municipality, Bangladesh

Groundwater quality (GWQ) is critical to public health but is increasingly threatened by both natural and anthropogenic pollution in Bangladesh. This study assessed the physicochemical characteristics, contamination sources, and potential health risks of groundwater (GW) in Kaliganj Municipality, located in Jhenaidah District in southwestern Bangladesh. Thirty GW samples were analyzed for key water quality parameters, including pH, total dissolved solids (TDS), calcium (Ca2+), bicarbonate (HCO3−), arsenic (As), iron (Fe), and manganese (Mn). The mean values were: pH 7.04 ± 0.21, TDS 273.67 ± 51.36 mg/L, Ca2+ 95.00 ± 23.05 mg/L, and HCO3− 388.24 ± 96.34 mg/L. Concentrations of As (0.03 ± 0.03 mg/L), Fe (0.72 ± 1.16 mg/L), and Mn (0.21 ± 0.24 mg/L) exceeded guideline limits in 16.67, 26.67, and 56.67% of samples, respectively. The water quality index (WQI) classified 26.67% of samples as ‘poor,’ 10% as ‘very poor,’ and 3.33% as ‘unsuitable’ for drinking. Health-risk assessment using hazard quotient (HQ) and hazard index (HI) revealed that approximately 54% of GW sources pose high chronic risks for adults and ∼50% for children via oral exposure. Multivariate analyses indicate that contamination arises mainly from geogenic processes, with additional influence from agricultural runoff and industrial effluents.