Abstract
How much, if at all, is leukemia risk in human beings increased by exposure to low levels of ionizing radiation? This question remains unanswered, and the controversy that it arouses generates great heat both in scientific and in lay forums. As nuclear power, supersonic transport and other programs develop, the question assumes increasing importance, but the data that would answer it are not forthcoming.One of the few pieces of relevant information on human beings is the fact that exposure in utero to the low dose levels delivered by diagnostic x-rays of the maternal abdomen or pelvis are associated with . . .