title: Letter: Mortality and natural fluoride content of drinking-water.
mesh_terms: D002118:Calcium / Q000032:analysis; D005457:Fluoridation / Q000009:adverse effects*; D005459:Fluorides / Q000032:analysis*; D006331:Heart Diseases / Q000401:mortality*; D006801:Humans; D014867:Water / Q000032:analysis*; D014881:Water Supply
chemical_list: D014867:Water; D005459:Fluorides; D002118:Calcium