Risk Assessment of Toxic and Essential Trace Metals on the Thyroid Health at the Tissue Level: The Significance of Lead and Selenium for Colloid Goiter Disease

The background level of lead (Pb) in drinking water in Serbia represents a significant health issue. The aim of study was to examine the content of significant toxic and essential trace metals (Mn, Ni, Cu, Zn, As, Se, Cd, Pb, Th, and U) in the thyroid tissues with diagnosed colloid goiter (CG). Different variables were investigated (sex, age, smoking habits, goiter size, and previous history of any thyroid disease). The study was designed to compare the goiter tissues (GTs) to sex- and age-matched healthy- and malignant-thyroid tissues (HTTs and MTTs, respectively). All trace metals were quantified by inductively coupled plasma mass spectrometry (ICP-MS). The reduced content of essential elements (Mn and Se) and increased content of toxic metals (Pb, Th, and U) were found in GTs compared with HTTs. The increased content of the same toxic metals separated GTs from MTTs, as well as reduced content of Mn and Cd. Our results indicated that Pb acts as the main goitrogen, which could highlight its role in the unknown etiology of CG disease. Pb/Se ratio could be considered as a relevant parameter for the tissue separation of GTs from HTTs and/or MTTs. This research also provides novel data on the effects of metal pollutants on thyroid health hazards.