Occupational exposures and thyroid cancer

Abstract

Thyroid cancer accounts for the majority of endocrine cancers, and the number of cases is increasing worldwide likely due to increased recognition more than a real increment of the disease. Exposure to ionizing radiation is the main occupational exposure related to thyroid cancer. Several studies were carried out on Chernobyl cleanup workers and healthcare professionals exposed to ionizing radiation. These reported a causal relationship between acute or cumulative exposure to moderate/high radiation dose and thyroid cancer, while there is less clear evidence that chronic exposure to low dose increases the risk. However, the excess risk reported in the majority of studies is likely overestimated because of a higher surveillance among workers whose activity entails exposure to ionizing radiation. Epidemiological studies on other occupational risks are scarce, and it is not possible to draw firm conclusions on other exposure agents, including pesticides, benzene, and formaldehyde as well as on workers employed in semiconductor, wood, paper, and textile industries.