that the major contributory factor to such effects such as nausea and vomiting associated with whole-body exposures of 100-200 roentgens, may be the result of the gastrointestinal reaction. Possibly a few hundred rads to the lower large intestine together with the concomitant lesser exposures to the upper large intestine, the small intestine and the stomach (according to Graph Five) may be in the range where . 2. wadiation sickness might occur. Thyroid The study and treatment of disorders of the thyroid gland with radioiodine has led to considerable information on doses and their effects to this organ. (Only a partial list of references is noted. )°1?22, 23, 2h, 25 Whereas these treatments have been principally with abnormal thyroids » much of the information may be extrapolated to normal thyroids for the purposes of this aiscussion. In addition there are other data based on normal thyroids in patients suffering such ailments as congestive heart failure 26 The picture that is clearly presented is that of the relative insensitiveness of the adult human thyroid to radiation. For example, Freedberg, Kurland, and Herman, report, "---Seven days after administra- tion of 17 and 20 millicuries of 123, which delivered 14,500 and 31,000 . rep, respectively, to the thyroid gland, no histologic changes were noted which could be attributed to p31, --- Fourteen and twenty-four days, respectively, after administration of 59 and 26 millicuries of q231, marked central destruction of the thyroid gland was noted.---" Since the first two patients expired seven days after administration of the y3t from pulmonary edema, it does not eliminate the possibility that the destructive DOE ARCHIVES LV we