EPFECTS OF TONIT'NG RADIATION did not refill, [In one instance, an extensive, raw, weeping ulcer developed for which penicillin was given for two days. During this time the lesion developed healthy granulation tissue. Some of the lesions of the skin of the foot remained thickened and less pliable after desquamation. This was reheved by the use of vaseline or cocoa butter to soften the tis- sues. The one persistent ear lesion did) not heal after desquamation, This was treated daly with warm boric acid compresses and washing: with surgical soap to remove the eschar. Slowly, regenerating epithelium grew in foom the edyes of the ulcer. Upon reexam- ination, 6 months after exposure, healing was complete with a depigmented scar remaining as eVidence of the previous uleoration. 3.5 3.51 Factors Influencing Severity of the Lesions Character of the Fallouc Marerial This material was composed mainly of calcn oxide from the imemerated coral, with adherent fission products. Fifty to eqrhts percentof the beta rays emanating from this material durin the exposure period had an avernye energy of about 100 kev. Since 8) m- eros of tissue produces od percent attenuation of such radiation (1), a greater portion of energy was dissipated in the epidernus which ix roughly 40 to 70 microns in thickness. The remaining 20 fo 60 percent of the beta rays had an average energy of approximately 600 kev. A The latter sould penetrate well into the dermis stipe it takes S00 guerons of tissue to produce A) percent attenuation of this energy radiation (12). In addition, a wide spectrum of yaintin energies irradiated the skin. The ganitna contribution to the skin was small compared to the beta dose and is discussed in Chapter EF. 3.52 Dose co che Skin 2 omargre er ointment, with apparent succes Whe the epithelium was deaquamating, all lesions were treated by claily washing with soap and water followed by the appheation of a water soluble vanishing type omtment which kept the in jured skin soft and pliable. Raw areas, which became secondarily infected, were cleansed with soap and aureomycin ointment: was applied. Bullous lesions of the feet were left intact ax long as no syniptoms were present. If painful, the fluid was aspirated with sterile technique and a pressure dressing applied. A single aspiration was adequate since the bullae rs, , M The skin lesions obyerved resulted primarily from beta radiation from fallout material de- posited on the skin. The gamma dose to the skin was small compared to the beta dose, and thus relatively unimportant in producing the lestons, The summation of gamma and beta contributions to the skin is considered in Section 1.3. In general it is evident that skin injury was largely produced by material in contact with the skin. The total surface dose cannot be calculated with accuracy but minimal and maximal values at various depths in the skin can be estimated biologically. Hair fol- lieles in the areas in which eptiation occurred Inust have received xa doge in excess of the known minimal epilating dose of about 400 r for 200 kvp X-ray. Since regrowth of hair occurred, the upper lint of dose at the depth of the har follicle must not have exceeded the permanent epilating dose of around 700 r of 200 avp M-ray 63). From this a rough idea of surface dose may be made. .A dose to the haw follicles comparable to 400-00 r of Xradiation must have been due almost entirely to the more penetrating beta component (avernyre energy, 600 kev). Therefore, the minimal surface dose in rep from this component alone was probably four to tive times the dose at the hair follele. 1 e., roughly 1,600-3,500 rep. The soft component (average energy, 100 kev) contribated a considerably larger share to the surface dose but with only slight penetration. 3.53 Protective Factors The following factors provided some protection:

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