deficiency. However in the past two years the 2 boys showing the greatest growth retardation have developed characteristics of frank hypothyroidisn with atropy of the thyroid gland, drop in PBI level to less than 2 pgi, development of coarse facial features, dry skin and Afchilles reflex with sluggish return and bone disgenesis. a primary hypothyroidism. High pituitary TSH levels indicated Several other children with less degree of growth retardation have recently shown some degree of thyroid deficiency also. In view of the seriousness of these findings it was decided to Fousne initiate thyroid hormone therapy on the exposed people. The rational now for this form of therapy was that by furnishing normal levels of exogenous thyroid hormone, pituitary TSH levels would be repressed and remove the thyroid gland from stimulation of that hormone. It is thus hoped that further development of nodules and possible malignancy might be prevented and of equal importance enhancement of growth and development in the children might result. Conclusive results of this treatment must await further observations and a stricter treatment regimen. However it does appear that several nodules have reduced on this treatment and some children may be showing increased growth. The next slide shows the results of hormone treatment on the 2 boys who had shown growth retardation, referred to before. It can be seen that there has been a spurt in skeletal development coincident with the institution of the thyroid therapy. The exclusive development of these thyroid abnormalities in the irradiated Marshallese children seems clearly to indicate the radiation etiology. The development of such abnormalities is consistent with the known etiological relationship of irradiation of the thyroid gland and the development of such lesions. The high incidence in the children is probably related to the larger € 5901249