Department of Environmental Studies, Institute of Science, Visva-Bharati, Santiniketan, Birbhum, West Bengal, 731235, India.
Environ Geochem Health. 2021 Nov;43(11):4515-4532. doi: 10.1007/s10653-021-00942-x. Epub 2021 Apr 24.
Ninety groundwater samples were collected from Khayrasole and Rajnagar blocks of Birbhum district, West Bengal, India, during pre-monsoon and post-monsoon in 2016 to assess the hazards of fluoride in groundwater. Fluoride concentration fluctuated from 0.3 to 17.6 mg/L, with 70% of samples reported beyond the modified regional optimal fluoride level (0.7 mg/L) with a statistically significant level of p < 1.7E-24. The average cation and anion concentrations exhibited a descending order of Ca > Mg > Na > K and HCO > Cl > SO > NO > F, respectively. Notably, groundwater quality in 50% of the places ranged from poor to unfit for drinking purposes in terms of water quality index. The mean total hazard index (THI) was 1.1 for adults and 1.9 for children, signifying a greater chance of non-carcinogenic threats to both age groups. In calculating the THI, ingestion and dermal pathways accounted for approximately 96% and 3% health hazards, respectively. The Monte Carlo simulation and sensitivity analysis identified that the diurnal water ingestion rate, exposure duration, and fluoride concentration were the significant sensitive variables that triggered most groundwater-associated non-carcinogenic health issues, signifying more risks among children. Further, dental health surveys (N = 746), following Dean's norms for classification based on regional optimal fluoride level, designated the borderline grade of the community dental hazard. The subsequent hydrogeochemical characterization directed that dissolution from fluoride-bearing minerals and water-rock interaction, such as halite dissolution and calcite-dolomite precipitation, were the governing factors for F enrichment in groundwater. This study will serve as baseline data for delineating fluoride-induced dental and other health hazards through sensitivity and spatial analysis in the GIS platform for hazard zonation and effective groundwater quality management.
2016 年季风前和季风后，从印度西孟加拉邦比尔布姆县的 Khayrasole 和 Rajnagar 两个区块采集了 90 个地下水样本，以评估地下水中氟化物的危害。氟化物浓度在 0.3 至 17.6 毫克/升之间波动，其中 70%的样本报告超出了改良后的区域最佳氟化物水平（0.7 毫克/升），p 值具有统计学意义，小于 1.7E-24。平均阳离子和阴离子浓度的顺序依次为 Ca > Mg > Na > K 和 HCO > Cl > SO > NO > F。值得注意的是，在 50%的地方，根据水质指数，地下水质量从差到不适宜饮用不等。成人的平均总危害指数（THI）为 1.1，儿童为 1.9，这表明这两个年龄段都面临着更大的非致癌威胁的可能性。在计算 THI 时，摄入和皮肤接触途径分别占大约 96%和 3%的健康危害。蒙特卡罗模拟和敏感性分析确定，日饮水量、暴露时间和氟化物浓度是引发大多数与地下水相关的非致癌健康问题的重要敏感变量，这表明儿童面临更大的风险。此外，根据区域最佳氟化物水平的分类标准，根据迪恩准则对 746 名牙科健康调查人员进行了调查，将社区牙科危害的边界等级定为临界等级。随后的水文地球化学特征表明，氟化物矿的溶解以及水岩相互作用，如岩盐溶解和方解石-白云石沉淀，是地下水中氟化物富集的控制因素。本研究将为通过 GIS 平台中的敏感性和空间分析来划定氟化物引起的牙齿和其他健康危害提供基础数据，以便进行危险分区和有效地下水质量管理。
