7 probably with less internal absorption of radionuclides, since their stored water and food were cov. ered, and they have had no thyroid cilects (see Appendis 2). Evaluation of the effects of radiation exposure in human beings (patients, physicians using radiation, accident cases, etc.) is always dillicult because ofuncertainties regarding exact dosage, lracuonaion and dose-rate ellects, partial-body exposure, complicating diseases, ete. The doses received by the Marshallese, ike most human exposures, could be only roughly estimated. although the hematological data were compatible with the cal- culated whole-body doses. Even greater uncertain: tes were Cacountered in estimating the doses due iG daternal absurpuon of radionuchides, The data on the effects of fallout radiation in the Marshallese have provided important infor- ination that will apply in a general way toa any population expused acutely to fallout However, the effects may be modified ip other situations if nuclear explosions aecur in regions with different terrain, soil iypes. climase, and availability ofproLeclive micasures. C. ACUTE EFFECTS ‘The most serious acute elfeets af the exposure in the Mfarshallese were due ta penctrating gam tia radiation, Vhese included transient anorexia, nausea, aad vomiting and significant depression af the petipherad bDlogd elements in mans members of the higher exposure Roneclap group. Phe henntolovical depression was not suflicrent to produce delinite clinical sizes ane requircd ne specifie therapy. Contamination of the skin in the Rongelap group resulted in wide-spread beta burns on parts of the body aot covered by clothing and in spouy epilation of the scalp. These effects were probably ageravated by delay in decontanunauion and by perspiration duc to the warn clinsate causing the fallawt te stick tothe skin. Phe superficial nature af the lesions, capal healing vith mien residual shin chanues, and ecurowth of Bair were uo doubt due to the lawaverage energy of the beta radiation inthe fallout. he lick af recognizable acute ellects from the Intenal absorption of radionuclides is noteworthy view of the serious thyroid abnoriuuidilies that auter developed. Because of residual contaninationon the islands, radiolowcal monitoring of personnel and environ nent has been an inpoertant part of the surveys in evaluating body burdens of radionuclides in the Rongelap and Utirik people. Recently the areas undergoing such monitoring have inchuded Bikini Atoll and the people who have returned to live there, and they will also include Eniwetok when its people return home. D. LATE EFFECTS ‘The possible emergence f late effecis of ex posure in the Marshallese has received considerable attention in follow-up examinations. Except for the thyroid lesions and the one case of leukemia, only a fewfindings possibly related to radiation exposure have been seen: otherwise the general incidence of illnesses and the overall physical con- dition have been similar in the exposed and in the unexposed comparison groups. The increase in miscarriages and stillbirths among the exposed Rongclap women during the first 3 vears after expesure may or may not have been related to radi- ation effects. No genctie ctlects have been noted in the children born of exposed parents: this is not surprising in view of the generally negative findings inthe much larger Japanese study. The findings of persistent chromosome aberrations in cultured peripheral blood Ivinphocytes at 10 vears past exposure and a possible somatic mutation 1 hemogiobin in several of the exposed group sug- gest that genetic mutations mayalso be present. The possibility of gencuc eflects in the offspring is of serious concern to the exposed people and de- serves further study, Etfeets of radiauionon life shortening of mortal- ity are difficult wo evaluate because of the small nusnber af people and the differences in age distribution between the exposed and companson groups. The only death that may be related to exposure is that from leukemia, Phe occurrence of a few adcitional cases afcancer (other than thyroid) cannot be ascribed definitely to radiation expo- sure. The Jack of skin cancer from beta burns may be related to the miniunad mavure af the residual skin changes, probably due to insuallicient radiation yure ta the dermis, but the possibility af skin cancer developing must be kent in mind: becuase the Latent period mia be very Jong. The dev clopment a ease of acute loukemia in the Rongelap bow may or may not be related to radiation exposure, Lawever, this disease appears to be even rarer in the Marshall [slands than in the US. Tois noteworthy that his disease was the