Department of Geology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, 9816745639, P.O. Box: 98135-674, Iran.
Department of Geology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, 9816745639, P.O. Box: 98135-674, Iran.
Ecotoxicol Environ Saf. 2020 Jun 1;195:110503. doi: 10.1016/j.ecoenv.2020.110503. Epub 2020 Mar 28.
Groundwater fluoride contamination is a major issue of water pollution in the world with health hazards such as dental and skeletal fluorosis. This research focused on exposure to the high concentration of fluoride in the springs water in the Bazman volcanic area, southeast Iran. The combination of chemical/isotopic analysis, geochemical modeling, health risk assessment and multivariate statistical methods were applied to investigate the contamination and sources of fluoride in the samples. Groundwater samples were collected from cold and thermal springs. Major ions, fluoride, trace elements and stable isotopes δO and δD were measured in the samples using standard methods, ICP-MS and OA-ICOS, respectively. Fluoride content in springs varied from 0.5 to 3.75 mg/L with an average value of 1.66 mg/L. The highest fluoride concentrations were observed in the eastern cold springs while thermal springs showed the minimum fluoride contents. The majority of samples showed F contents higher than the calculated optimal concentration of fluoride (0.75 mg/L). Reaction of fluorite mineral with HCO and replacement of F in clay minerals and metal oxy-hydroxides with OH in water were likely cause fluoride enrichment in the eastern springs. Whereas, in the western springs and thermal springs, origin of fluoride was related to weathering of muscovite, cryolite, apatite and fluoroapatite minerals. The δO and δH of the water samples displayed the impact on evaporation on fluoride enrichment in all spring water samples. The average value of contamination index (C) in the water samples was 1.94 categorizing medium risk level while springs S7, S8, S9 and S4 were above the threshold value of C index. The fluoride hazard quotient (HQ) showed that 25%, 44%, 56% and 0% of springs' water resources had high risk level for age group of adults, teenager, children and infants, respectively. Therefore, health risk of fluoride in drinking water resources were in the following order: children > teenager > adults > infants.
地下水氟污染是世界范围内水污染的一个主要问题，会对人体健康造成危害，如氟斑牙和氟骨症。本研究集中于伊朗东南部巴兹曼火山地区温泉水中氟浓度高的暴露问题。采用化学/同位素分析、地球化学模拟、健康风险评估和多元统计方法相结合的方式，对样品中的氟污染和来源进行了研究。采集了冷水和温泉水的地下水样本。采用标准方法、ICP-MS 和 OA-ICOS 分别测量了样品中的主要离子、氟、微量元素和稳定同位素 δO 和 δD。温泉水中的氟含量从 0.5 到 3.75mg/L 不等，平均值为 1.66mg/L。东部冷水温泉中的氟浓度最高，而热泉中的氟浓度最低。大多数样品的 F 含量高于计算得到的最佳氟浓度（0.75mg/L）。萤石矿物与 HCO 的反应以及氟在粘土矿物和金属氢氧化物中的取代反应和水中 OH 的取代反应可能是导致东部温泉中氟富集的原因。而在西部温泉和热泉中，氟的来源与白云母、冰晶石、磷灰石和氟磷灰石矿物的风化有关。水样的 δO 和 δH 表明，蒸发对所有温泉水中氟的富集都有影响。水样的平均污染指数（C）值为 1.94，属于中等风险水平，而 S7、S8、S9 和 S4 等温泉的 C 指数超过了阈值。氟危害系数（HQ）表明，25%、44%、56%和 0%的温泉水资源对成年人、青少年、儿童和婴儿的氟暴露有高风险水平。因此，饮用水源中氟的健康风险如下：儿童＞青少年＞成年人＞婴儿。
