a few days, months, or years. high doses, This appears to be true especially with although evidence from low doses with animals indicaves that irradiation may, indeed, lengthen life somewhat, although at the same time the life span of the group is not increased. Since life-span studies involve long periods of time (20-40 years), results so far have proved inconclusive; however, it is generally accepted by scientists that high doses of radiation more than likely lead to shortening of the life span, through the production of malignant tumors. shortened from nonmaliscnant Whether or not life may be causes is still in doubt. Stillbirths, Miscarriages, Fertility It has previously been thought that irradiation of the fetus, as it is growing inside the mother, may cause birth of a dead child (still- birth), or early delivery of the fetus (miscarriage). Loss of fertility (temporary sterility) of the mother or father can also be caused by radiation. Evidence is still unclear in regard to most of these effects. ~ Kumatori's study of Japanese fishermen exposed to the Bravo fallout did, however, indicate loss of fertility of the men through depressed, or greatly reduced, production of sperm cells (75, p. 22), which would indicate that irradiation does indeed affect human fertility. While findings on miscarriages and stillbirths are inconclusive, there are other effects on the developing child (fetus) irradiated inside the mother which were discussed previously or will be discussed later. Growth and Development Children irradiated before birth have been studied in both Japan and the Marshall Islands. In both instances it has been found that such children show reduced height and weight and growth retardation, ranging from slight to severe. More detailed discussion of these findings will be included in the relevant chanters to follow. 28