NEW YORK (Reuters Health) - Babies that were exposed in the womb to radioactive iodine after the 1986 Chernobyl nuclear power plant accident have had an increased risk of developing thyroid cancer in the ensuing 20 years, according to a new report.
Previous studies have linked thyroid cancer to radioactive iodine from Chernobyl, the authors say, but there’s little information on survivors who were exposed before they were born.
Dr. Maureen Hatch from the National Cancer Institute in Rockville, Maryland, and colleagues evaluated the risks of thyroid cancer and other thyroid diseases in 1494 children born to mothers who were pregnant at the time of the accident, compared with 1088 children of mothers who became pregnant when fallout was no longer present.
Screening revealed six cases of thyroid cancer and one precancer in the contaminated group, compared with one case of thyroid cancer in the later group, the investigators report in the Journal of Clinical Endocrinology & Metabolism.
Each unit of radioactivity exposure increased the risk of thyroid cancer about 11-fold, the researchers note.
“I would like to do an additional screening of the population in 3-5 years’ time to see if the number of cases increases,” Hatch said.
There was no apparent increase in the risk of other thyroid diseases related to exposure to radioactive iodine in the womb.
The main message from these findings, Hatch commented, is “to be extremely cautious” about the medical use of the radioactive isotope iodine-131 to treat an overactive thyroid in pregnant women.
SOURCE: The Journal of Clinical Endocrinology & Metabolism, March 2009.