EFFECTS OF FALLOUT RADIATION 289 increased y-globulin (mean of 2.4 gm). The explanation for these findings is not immediately apparent. An unexpected finding is a generally high protein-bound todine value (mean value for the population, 9.4 ug per 100 ml). The explanation for this is not apparent, particularly in view of the fact that the people do not clinically appear to be hyperthyroid. Serion cholesterols and creatinine levels were found to be within normal limits. C. Beta Lesions oF THE SKIN, EprILaTION Multiple p-ray lesions of the skin, mainly on the areas of the body not covered by clothing, and spotty epilation associated with 8-ray lesions of the scalp appeared in manyof the people beginning 12 to 14 days after exposure and continuing over the following few weeks. Most of the lesions were superficial and were characterized by thickening and pigmentation of the skin accompanied by mild itching and burning. Desquamation followed, with healing and repigmentation over the next few weekx. Regrowth of hair began about 3 months after exposure, with complete return of normal hair by 6 months. About 20% of the cases exhibited more severe lesions whichulcerated, but, in all except one severe ear lesion, complete healing oecurred within a few weeks. Microscopic changes were characteristic of radiation effects, with the epidermis showing the greatest damage. About 14 cases continue to showresidual changes at this time characterized by mild scarring and atrophy and varving degrees of decreased and, in some cases, increased pigmentation. In no case, either grossly or microscopically, has any malignant or premalignant change been observed. D. Ixterxnat Ansorrrion or Rapioactive Isorores At present the accumulated evidence supports an assumption madeinitially that after contamination by fallout the radiation dose from external sources would be higher than that from internally deposited sources. Because, however, so relatively little is known about the mechanisms and consequences of internal deposition of fission products, study of this phase of the problem was among thefirst of the studies undertaken in 1954 and has continued to be a part of subsequent re-examinations of the exposed population. A few short-lived radioisotopes, I, Sr8°, and Ba°, accounted for most of the activity found in urine specimens obtained during the first 24 days after the contaminating event. Analysis of the 24-day urines performed 2 years later showed that the samples also contained some Sr® and Cs!’, The Sractivity in the urine decreased from 12 d/m/I in the 24-day specimens to 0.34 to 1.41 d/m/] in the 1957 specimens. The Sr* analyses on urine samples taken in the 4-year survey have not been completed. The Cs" urinary activity fluctuated, decreasing from 174