Abstract
IN the last decade epidemiologic research has contributed evidence implicating ionizing radiation and chromosomal aberrations in the genesis of leukemia. By comparison, the epidemiologic evidence for the viral etiology of human leukemia is scanty despite the anticipation generated by continuing successes in identifying leukemogenic viruses in mice.As is true of other research approaches, epidemiology may describe a disease, explore it empirically or test specific ideas about it. The patterns of leukemia mortality that have been ascertained by descriptive epidemiology, though they do not per se suggest the etiology, do provide considerable intelligence against which suspected principal causes of the . . .