Abstract — Combined ecological and geochemical assessment was performed for the major- and trace-element composition of groundwater of Bryansk oblast used for drinking water supply, and settlements and districts were ranked with respect to the contents of I, Se, and some other chemical elements and their concentrations were compared with the existing hygienic standards. It was shown that the I and Se contents of drinking water is controlled by the geochemical conditions of water formation and do not reach physiological optimum levels (10 mg/L for I and 2.5–3.3 mg/L for Se) in most districts of the oblast, which could intensify the adverse response of the thyroid gland (TG) to the contamination of the region with I-131 during the Chernobyl nuclear accident of 1986. Furthermore, we revealed other unfavorable hydrochemical factors, which may influence the distribution of natural endemic diseases among local inhabitants related to local elevated concentrations of Mn (up to 10 MPC), Fe (up to 26 MPC), Si, and Sr (up to 2 MPC) in drinking waters confined to certain hydrogeologic complexes.

中文翻译：

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布良斯克州饮用水化学成分的生态和地球化学评估与甲状腺疾病风险增加的应用

摘 要——对布良斯克州饮用水供水用地下水的主微量元素组成进行生态地球化学联合评价，根据I、Se等化学元素的含量对居民点和地区进行排序。并将它们的浓度与现有的卫生标准进行比较。结果表明，饮用水中 I 和 Se 的含量受水形成的地球化学条件控制，在大部分地区未达到生理最佳水平（I 为 10 mg/L，Se 为 2.5-3.3 mg/L）。在 1986 年切尔诺贝利核事故期间，这可能会加剧甲状腺 (TG) 对该地区 I-131 污染的不良反应。 此外，我们揭示了其他不利的水化学因素，