EFFECTS OF LOW-LEVEL RADIATION FROM THE CHERNOBYL ACCIDENT IN A POPULATION WITH IODINE DEFICIENCY

To determine the effects of low dose radiation from I-131 and Cs-137 r esulting from the Chernobyl disaster on the expression of endemic goit er in children, we studied children in regions with and without eviden ce of radiocontamination but comparable iodine insufficiency. We inclu ded 89 children in the study (radiocontaminated) region (SR) and 116 i n the control region (CR) because they were either fetuses, infants, o r pre-adolescents at the time of exposure, We evaluated thyroid dimens ions by clinical examination and ultrasound; thyroid function by hormo nal levels, and thyroglobulin measurement; histology of the thyroid by fine needle aspiration; and thyroid autoimmunity. SR subjects had 5 t imes the frequency of thyroid enlargement as those from CRI greatest i n the younger patients. There were no instances of clinically apparent thyroid dysfunction. Antithyroid microsomal and antithyroglobulin ant ibodies were present in a markedly greater percent-age of SR subjects. Fine needle biopsy demonstrated greater cellular proliferation in sam ples from SR. Conclusions We have demonstrated: findings of autoimmune thyroid disease at markedly increased frequency in a population of ch ildren with poor iodine nutriture who were exposed to low level radiat ion, compared to a more iodine deficient population not so exposed. Th ese results suggest that low level radiation may induce thyroid gland changes in children who have inadequate iodine intake nutriture and re inforce the importance of adequate dietary iodine.