of healing, and absence of pigmentation, These points would apply tu the Marshallese except . for the multiphasic reactions and pigmentation. Crawford® reports a case of cathode ray burns of the hands which were similar to those described by Robbins, et al! Experimental beta radiation burng in human beings have been reported by Low- Beer? and Wirth and Raper, Both invest iwatora used. P*? discs apphed (o the flexor surfaces of the arms, forearms, or thighs for varying lengths of time. Low Beer reported “monephaste” skin reactions. He found thal a calculated dose of 143 rep to the first millimeter of skin, tgnering self-absorption, produced a threshold erythema. Dry, scaly, desquamation was produced by 7200 rep in the first millimeter and bullous, wet desquamation was produced by 17,000 rep to the first millimeter, Erythema developed in 3 to 4 days, followed Liter by pigmentation and desyuamation with higher doses. Recovery was observed with doses of 17,000 rep, ‘The lestons later showed depigmented centers with hyperpigmented edges (also scen in the present lesions). © Wirth and Raper’® produced primary erythema within 6 hours after exposure to a dose of 635 to 1180 rep of P*? radiation. Minute vesicles with dry, spotly desquamation were noted with 1180 rep at about the Sth to 6th weeks puosl-expusure. Folluwing the detonation on 1 March 1954, 23 Japanese fishermen were contaminated with fallout material. Apparently they were exposed to roughly the same total-body dose uf radia- tion as were the Rongelap group. The skin lesions which developed are described by Morton, et al.''!? Lesions developed which were similar in most respects to those seen in the Mar-~ shallese people, and were characterized by pigmentation, desquamation with depigmentation, spotty epilation of the head and ulcerations developing particularly on the scalp, ears, neck, and hands (the latter probably from handling contaminated fishing lines). Erythema and vesicle formation, as well as inflammation of the eyes were more prominent than in the Marshallese. Pigmentation apparently was not as prominent in the Japanese. The lesions appeared earlier than in the Marshallese (about 7 to 8 days post-exy 29sure). As in the Marghallese the lesions occurred mainly on exposed parts of the body not protected by clothing. In addition to the Marshallese and Japanese, several Navy men on ships in the test area developed a few small pigmented lesions of “belt-line” distribution, apparently due to fallout material. . ~t The lesions reported in this paper when compared tu radiation lesions described in the past presented certain unique features which merit further discugston. The carly symptoms of itching and burning of the skin and eyes were probably due mainly to skin irradiation from the fallout material. However, the chemical nature of this material may have contributed to the irritation, It has been noted’? that irritating chemicals applied during or shortly after irradiation enhance the effects of radiation. The: Jack of prominence of an erythema was notable, particularly in view of the severity of some of the lesions that developed. Wilhelmy?!‘ states that erythema only occurs when the dose reaching the papillary layer exceeds a certain level. Perhaps the dose to the dermis was in- sufficient tu evoke the response. On the other hand, the darkness of the skin and the development of hyperpigmentation may have masked an erythema. Microscopically, a superficial _ hyperemia was not a notable finding. Wirth and Raper’® point out that they were impressed in their studies on P*? radiation of the human skin_with the difficulty of distinguishing between true erythema and tanning, par- ticulariy in the ekin of brunette individuals. It was unfortunate that color filters were not available to aid in distinguishing an erythema as suggested by Harris, et al,!8 In general the latent period before development of obvious signs and symptoms for radiation injury to the skin is inversely proportional to the dose of radiation.'8"" In the present series of cases the relatively long latent period ts suggestive of a low dose of radiation. However, the wide spectrum of beta energies and particulate distribution of radivactive material drastically altered the depth dose, as compared with that in previous experience; hence strict comparisons cannot be made. The later development of lesions 1n the Ailinginae and Rongerik groups as contrasted with the Rongelap people 1s in keeping with the relative severity of lesions noted. 43