Contents of Nineteen Chemical Elements in Thyroid Benign Nodules and Tissue adjacent to Nodules investigated using X-Ray Fluorescence and Neutron Activation Analysis

Thyroid benign nodules (TBNs) are the most common diseases of this endocrine gland and are common worldwide. The etiology and pathogenesis of TBNs must be considered as multifactorial. The present study was performed to clarify the role of some chemical elements (ChEs) in the etiology of these thyroid disorders. Thyroid tissue levels of Ag, Ca, Cl, Co, Cr, Cu, Fe, Hg, I, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Sr, and Zn were prospectively evaluated in nodular tissue and tissue adjacent to nodules of 79 patients with TBNs. Measurements were performed using X-ray fluorescence and instrumental neutron activation analysis. Results of the study were additionally compared with previously obtained data for the same ChEs in “normal” thyroid tissue. It was observed that mass fractions of Ag, Cl, Co, Cr, Cu, Fe, Hg, Mn, Na, and Sc contents in “nodular” tissue were higher, while Ca and I content was lower in comparison with contents of these ChEs in normal gland. Mass fractions of Ag, Cl, Hg, Na, and Rb in “adjacent” group of samples were approximately 31, 2.7, 32, 1.6, and 1.3 times higher, respectively, than in “normal” thyroid. Contents of Cr, Fe, Sc, and Se were lower, while mass fraction of Hg and I higher in “adjacent” group of samples in comparison with nodular tissue. At that, level of I in “adjacent” group of samples was over 2 times higher than in nodular tissue and almost equals the normal value. This study provides evidence on many ChEs level alteration in nodular and adjacent to nodule tissue and shows the necessity to continue ChEs research of TBNs. The little reduced level of I content in nodular tissue could possibly be explored for differential diagnosis of TBNs and thyroid cancer.