Twenty Year Incidence of Stomach Cancer

Note the Red is highest incidence, Light Blue or Light Olive is lowest, and white is inadequate data. The highest incidence of stomach cancer 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. Note the high incidence of nonwhite people at the mouth of the Mississippi River, and upriver in Mississippi and Tennessee for nonwhite females. Some evidence of pesticide residue from cotton fields in drinking water interacting with chlorine in water treatment may be a major contributor. The nonwhite population tended to have contaminated water in small towns or even treatmented home supplies. This was not the case with the white population. If the cause was genetic diversity between males and females, or whites and nonwhites, the incidence would be uniform.