Asymptomatic Effect of Occupational Radiation Exposure on Thyroid Gland Hormones and Thyroid Gland Ultrasonographic Abnormalities

Data evaluating the effect of asymptomatic effects of radiation on thyroid hormone panels and ultrasonographic abnormalities among radiology technologists are scarce. This study aimed to determine the asymptomatic effect of radiation in a total of 39 male and 11 female exposed radiology technologists working in radiology departments, and a total of 34 male and 16 female age-matched controls working in other departments in the same hospital. The level of triiodothyronine (T₃), thyroxine (T₄) and thyroid-stimulating hormone (TSH) were evaluated using Enzyme Linked Immunosorbent Assay (ELISA). Thyroid ultrasonographic evaluation outcomes were given as normal or abnormal. There was significant interaction between exposure and gender in the mean TSH and T₄ but not T₃. The mean TSH for exposed men was significantly higher than that among non-exposed men (2.28 mIU/L vs. 1.59 mIU/L; p-value = 0.003). The mean TSH was not significantly different between exposed and non-exposed women. The mean T₄ for exposed men was significantly higher when compared with non-exposed men (11.1 pmol/L vs. 10.05 pmol/L; p-value = 0.005). In the non-exposed group, 93.8% of women and 94.1% of men had T₄ values lower than established normal reference range, while in the exposed group, 90.9% of women and 74.4% of men had low values of T₄. There was no significant difference in mean T₃ between exposed and non-exposed groups for men and women. Furthermore, there were no significant differences in the thyroid gland ultrasonographic findings between exposed and non-exposed groups. Occupational radiation exposure is associated with increased means of TSH and T₃, especially among men.