Evidence for an intimate geochemical factor in the etiology of esophageal cancer.
Epidemiological data for esophageal cancer in the Butterworth District, Transkei, was used to calculate incidence contours which confirmed large variations within short distances (less than 5 km). High- and low-risk zones were demarcated, and a close relationship with underlying geology observed. The low-incidence zones in the study regions were underlain by dolerite intrusions, whereas higher-risk regions were on sedimentary strata. Analysis of rocks indicated that those from the higher-risk regions contain less copper, cobalt, and manganese. Soil samples were analyzed for boron, cobalt, copper, manganese, molybdenum, nickel, sodium, lead, vanadium, and zinc; the results also indicated a strong geochemical association with the disease. The concentrations of copper (P = 0.001), nickel (P = 0.001), and boron were markedly lower in the high-risk zones. Manganese, zinc, and molybdenum levels in soils also tended to be substantially lower in the high-risk zone.
D000328:Adult; D004812:Epidemiologic Methods; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000209:etiology*; D055593:Geological Phenomena; D005844:Geology; D006801:Humans; D008903:Minerals / Q000032:analysis* / Q000506:poisoning; D012042:Registries; D012306:Risk; D012424:Rural Population; D012987:Soil / Q000032:analysis*; D013019:South Africa
D008903:Minerals; D012987:Soil