Hydrogeology Group, Institute of Geological Sciences, Freie Universität Berlin, 12249, Berlin, Germany.
Department of Chemistry, Tripura University, Suryamaninagar, Tripura, 799 022, India.
Environ Geochem Health. 2020 Nov;42(11):3819-3839. doi: 10.1007/s10653-020-00637-9. Epub 2020 Jun 29.
Monitoring the groundwater chemical composition and identifying the presence of pollutants is an integral part of any comprehensive groundwater management strategy. The present study was conducted in a part of West Tripura, northeast India, to investigate the presence and sources of trace metals in groundwater and the risk to human health due to direct ingestion of groundwater. Samples were collected from 68 locations twice a year from 2016 to 2018. Mixed Ca-Mg-HCO, Ca-Cl and Ca-Mg-Cl were the main groundwater types. Hydrogeochemical methods showed groundwater mineralization due to (1) carbonate dissolution, (2) silicate weathering, (3) cation exchange processes and (4) anthropogenic sources. Occurrence of faecal coliforms increased in groundwater after monsoons. Nitrate and microbial contamination from wastewater infiltration were apparent. Iron, manganese, lead, cadmium and arsenic were above the drinking water limits prescribed by the Bureau of Indian Standards. Water quality index indicated 1.5% had poor, 8.7% had marginal, 16.2% had fair, 66.2% had good and 7.4% had excellent water quality. Correlation and principal component analysis reiterated the sources of major ions and trace metals identified from hydrogeochemical methods. Human exposure assessment suggests health risk due to high iron in groundwater. The presence of unsafe levels of trace metals in groundwater requires proper treatment measures before domestic use.
监测地下水的化学成分并识别污染物的存在是任何全面地下水管理策略的组成部分。本研究在印度东北部的西特里普拉邦的一部分进行，旨在调查地下水中痕量金属的存在和来源，以及由于直接饮用地下水而对人体健康造成的风险。从 2016 年到 2018 年，每年两次从 68 个地点采集样本。混合 Ca-Mg-HCO、Ca-Cl 和 Ca-Mg-Cl 是主要的地下水类型。水地球化学方法表明，地下水矿化是由于（1）碳酸盐溶解，（2）硅酸盐风化，（3）阳离子交换过程和（4）人为来源。雨季过后，地下水中粪便大肠菌群的出现增加。废水渗透导致硝酸盐和微生物污染明显。铁、锰、铅、镉和砷的含量超过了印度标准局规定的饮用水限值。水质指数表明，1.5%的水水质较差，8.7%的水水质勉强可以接受，16.2%的水水质良好，66.2%的水水质优良，7.4%的水水质极好。相关性和主成分分析重申了从水地球化学方法中确定的主要离子和痕量金属的来源。人体暴露评估表明，由于地下水中铁含量高，存在健康风险。在将地下水用于家庭用途之前，需要采取适当的处理措施，以去除不安全水平的痕量金属。
