Probabilistic Assessment of Non‐Carcinogenic Health Risks Posed by Groundwater Iron and Fluoride in Indo‐Bangladesh International Frontier Town in West Bengal, India

ABSTRACT During the post‐monsoon season of 2023, groundwater quality in 25 wards of Balurghat Municipality, a frontier town in Dakshin Dinajpur District of West Bengal along the Indo‐Bangladesh border, was evaluated. Information on groundwater quality, its suitability for drinking, and associated health risks in this area are scarce, despite this region's growing reliance on it. A comprehensive assessment of fluoride (F − ) and iron (Fe) concentration, hydrogeochemical facies, and estimation of the entropy‐weighted water quality index (EWQI) in conjunction with health risk modeling addresses the said research gap. The findings indicate that 96% and 64% of the samples had Fe and F − levels above the respective BIS and WHO safe limits. Hydrogeochemical analysis revealed Na‐HCO 3 and Ca‐HCO 3 as the two principal types of water. According to the EWQI, only 8% of the samples were fit for human consumption, 64% were moderately fit, while 28% were not fit. As per non‐carcinogenic health risk assessment by deploying Hazard Quotient (HQ) values, F − exposure was estimated to be > 1 in all age groups, with children having the highest HQ values, followed by infants and adults. For both F − and Fe, Monte Carlo simulations (10,000 and 5000 trials using Microsoft Excel and Oracle Crystal Ball software) verified increased risks, especially in younger populations. This study provides a robust insight into groundwater quality in an international border region and highlights the pressing need for the provision of clean drinking water towards protection of public health.