PROTECTION OF THE THYROID-GLAND IN CHILDR EN AND FETUSES IN CASE OF NUCLEAR-EXPOSURE

The administration of stable iodine in order to keep the thyroid gland away from radioactive iodine isotope contamination has long been rega rded with caution by the health authorities, mainly because of the pot ential toxicity of iodine in newborns, young children and adults with thyroid pathology. Therefore, the risk of oral stable iodine given for a limited period of time must be compared to the risk of cancer due t o radioactive exposure. The analysis of complications following the nu clear accidents of Marshall Islands in 1954 and Tchernobyl in 1986 has shown that newborn infants and young children have the highest risk, the main complications being cancer (papillary carcinoma) and hypothyr oidism. In the most exposed areas of Bielorussia, the incidence of chi ld thyroid cancer has been approximately multiplied by 100. On the oth er hand, studies of children from Utah who were contaminated after nuc lear tests in the Nevada desert have shown that following mild iodine radiaoctive exposure, the risk is not significant. Among complications attributed to stable iodine, only those related to an oral intake ove r a limited period of time should be considered. On the basis of nucle ar medicine experience and scientific literature, the risk can be cons idered as negligible in adults but not in children. However, the Polis h experience in children has reported a low risk and only benign compl ications, mainly transient hypothyroidism. Thus from current knowledge , it appears that the potent risks linked to stable iodine administrat ion should not contraindicate the collective preventive stable iodine administration in case of nuclear accident.