Figure 9. Early beta burns of skin ( x 100), showing extensive transepidermal damage, with milder damage to dermis showingcellular infiltration.? Table 7 ‘Epilation in Rongelap Group?? Incidence, % Severity of epilation Figure§. Neck lesions at26days, showing wet desquamgtion: ° =a ww AgeOto5 (13) Age6tol5 (13) Age >16 (38) Slight (14+) Moderate (2+) Severe (3+) 7.6 38.6 53.8 38.4 30.7 23.0 13.8 3.5 8.3 Total 100.0 92.1 276 usually more severe, often with bullae formation: they made walking painful and in somecasesinvolved secondary infections. Most of the lesions healed rapidly, with repigmentation. Microscopic studies and numerousskin biopsies during the acute stages of the lesions revealed marked epidermal injury with considerable atrophyandflatteningofrete pegs, cells with pleomorphic nuclei, pyknosis and cytoplasmic halos, andgiantcells (see Figure 9). Cells laden with pigmentwere frequently present throughoutthe epidermis, probably accounting for the gross pigmentation of the lesions. Severe damageto the dermis and blood vessels was not observed. An unusualobservation was the developmentof transient bluish-brown pigmentation of the semilunarareasof the fingernails and toenails, first noted about 3 weeks post exposure in most ofthe Rongelap and Ailingnae people and seen, among the American group,only in Negroes. The cause of this pigmentation remains obscure. Since nospecific treatmentis knownfor beta burns, the lesions were treated by cleansing and use of ointments andlotions for symptomaticre- Figure 8. Footlesions at 29 days, showing deep involvement betweenfirst and second toes.?