Twenty Year Incidence of Leukemia

Note the Red is highest incidence, Light blue is lowest, and white is inadequate data. The highest incidence of leukemia indicates some aspect of workspace, life style, or other environmental feature with a chronic exposure of a mutagen. This heterogeneity is the first clue for an investigation to identify the environmental hazard. If the cause was genetic diversity between males and females, or whites and nonwhites, the incidence would be uniform.