title: [Copper, iron, magnesium and zinc contents in hair of peasants in high and low incidence areas of esophageal cancer].
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002681:China; D003300:Copper / Q000032:analysis; D004938:Esophageal Neoplasms / Q000453:epidemiology*; D006197:Hair / Q000032:analysis*; D006801:Humans; D007501:Iron / Q000032:analysis; D008274:Magnesium / Q000032:analysis; D008297:Male; D008875:Middle Aged; D014131:Trace Elements / Q000032:analysis*; D015032:Zinc / Q000032:analysis
chemical_list: D014131:Trace Elements; D003300:Copper; D007501:Iron; D008274:Magnesium; D015032:Zinc