According to a study of Ukrainians who were under the age of 18 at the time of the Chornobyl accident, risk of thyroid cancer increased with increasing levels of radiation exposure. These results were published in the Journal of the National Cancer Institute.
The thyroid gland is located in the front of the neck and is attached to the lower part of the voice box (larynx) and to the upper part of the windpipe (trachea). It has two sides, or lobes, that are connected by a narrow neck. The thyroid gland produces thyroid hormones, which regulate metabolism, growth, and development.
Factors that increase the risk of developing thyroid cancer include radiation exposure, goiter, and a family history of thyroid cancer.
The 1986 Chornobyl accident exposed residents of Belarus, Ukraine, and the Russian Federation to substantial radiation. The radioactive fallout from the accident included radioactive types of iodine and cesium.
To describe the risk of thyroid cancer among residents of Ukraine who were children or adolescents at the time of the accident, researchers conducted a study among more than 13,000 individuals who were under the age of 18 in 1986. These individuals are being screened for thyroid cancer every two years. The current report describes the results from the first round of screening, conducted between 1998 and 2000.
- 45 cases of thyroid cancer were identified during the first round of screening. Had the Chornobyl accident not occurred, only 11 cases would have been expected.
- The likelihood of thyroid cancer increased with increasing radiation exposure
- There was some suggestion that risk of thyroid cancer was greater among those who were younger at the time of the accident.
The researchers conclude that exposure to radioactive iodine as a result of the Chornobyl accident greatly increased the risk of thyroid cancer among residents of Ukraine who were children or adolescents at the time of the accident. The researchers note that it may not be possible to generalize these results with similar accidents because there could be differences in the nature of the radioactive iodines involved, the pattern of exposure, or the susceptibility of the exposed population.
Reference: Tronko MD, Howe GR, Bogdanova TI et al. A Cohort Study of Thyroid Cancer and Other Thyroid Diseases After the Chornobyl Accident: Thyroid Cancer in Ukraine Detected During First Screening. Journal of the National Cancer Institute . 2006;98:897-903.