Lithium and Selenium Concentrations in the Drinking Waters of a Mountainous Village (Săcalu De Pădure): Potential Relationship to Residual Thyroid Pathology (Preliminary Research)

The lithium excess and selenium deficiency in the body can lead to thyroid disorders (goiter and hypothyroidism). We hypothesize that these elements can contribute to the persistence of thyroid pathology after the universal salt iodination introduced in 2002−2003 in Romania. The concentrations of lithium, selenium, and other micro- and macro-elements, as well as anions, were measured in the well waters used for drinking in the mountain village of Săcalu de Pădure, Upper Mureș Valley. Li concentrations (13 measures), ranging from 9.7 to 69 µg/L, generally exceeded the non-regulatory Health-Based Screening Level (HBSL) of 10 µg/L by 2 to 7 times, sustaining the contribution of Li excess to residual thyroid pathology. Additionally, these waters may be effective in treating mania, suicidal tendencies, Alzheimer's disease, and migraine. The selenium levels, measured in this and 5 surrounding localities (11 assays), were very low, under the detection limit. While the maximum limit for selenium content in drinking water is 20 µg/L (OG 7/2023), no lower limit has been established. Urinary iodine excretion, measured in 22 randomly selected residents, had normal values (100-350 µg/L) in most cases (90.9%), indicating an adequate iodine supply and excluding the iodine role in the residual thyroid pathology.