Thyroid Disorders in Employees of a Nuclear Power Plant

Background: The thyroid gland is a potential target organ for radiation-related damage. The aim of this analysis was to investigate the association between occupational exposure to ionizing radiation and the risk of autoimmune thyroid disease as well as thyroid nodules and dysfunction in workers of a former nuclear power station. Methods: Seventy-one male power station workers 38 to 57 years of gae who had been exposed to a lifetime dose in the upper allowed range (accumulated lifetime dose 70 to 400 mSv) were compared to a population- based sample of 670 males who were not exposed to occupational radiation. Thyroid ultrasound was performed by the same observers. Laboratory parameters were analyzed in a central laboratory. Results: After controlling analyses for age and further relevant confounders no significant differences with respect to thyroid nodules and markers of autoimmune thyroid disease were detected between exposed and nonexposed individuals. However, nuclear power plant employees had higher odds for elevated serum thyrotropin (TSH) levels than the reference group (odds ratio 4.54; 95% confidence interval 1.43; 13.91). Conclusions: Workers of a nuclear power plant with occupational exposure to ionizing radiation within the upper allowed dose range have an increased risk of elevated serum TSH levels. Further studies are required to confirm possible effects of occupational exposure to radiation on thyroid function.