-15- unexposed population was detected. 12.7.4 Fertility and Genetic Effects. Based on birth rates, fertility has been about equal in the exposed and unexposed populations. However about twice the number of miscarriages and stillbirths occurred in the exposed. women during the first 4 years after exposure (417% or 13 of 32 pregnancies in the exposed and 16% or 8 of 49 pregnancies in the unexposed women). Fetal abnormalities do not appear to have been more numerous in the exposed group, though no specific genetic studies have been carried out. A low level of persisting chromosomal aberrations of the lymphocytes of the peripheral blood of the type induced by radiation have been noted at 10 years post exposure(Lisco and Conard) ,(see Fig. 12.7.5 17). Cancer and Leukemia. No leukemia has been detected. The occurrence of 3 cases of cancer in the exposed group(2 of the female genital tract and 1 of the thyroid gland) represents a higher incidence in the exposed group, but due to the small numbers of people involved no correlation with radiation exposure can be made at this time. 12.7.6 Lens Opacities. Frequent slit-lamp observations have revealed no opacities of the lens characteristic of radiation exposure.* 12.7.7 Skin. Some degree of atrophy and scarring persisting in skin areas that had been more heavily irradiated have been noted (Fig. 11). Biopsies at these sites revealed that none of the lesions were neoplastic or showed alterations suggestive of a precancerous condition. In a few cases increasing numbers of pigmented maculae and moles have been noted in the areas of "beta *Ophthaimological studies have been carried out by Colonel Austin Lowrey, MC USA, Ret 5001312