Voors, A. W. (School of Public Health, Univ. of North Carolina, Chapel Hill, N.C. 27514). Minerals in the municipal water and atherosclerotic heart death. Amer J Epidem 93: 259–266, 1971.—A search was made for the active principle in hard drinking water accounting for its often observed negative correlation with atherosclerotic heart disease (AHD). Although conceivably mineral elements can cause AHD either through oversupply (toxicity) or through undersupply (deficiency), only potentially deficient minerals were considered. In the current biological literature, deficiencies of six metals have been implicated as possible causes of AHD: calcium, chromium, lithium, magnesium, vanadium and zinc. Each of these six metals was considered separately, while keeping the others constant, one at a time, and the appropriate product-moment partial correlation coefficients were tested against the null-hypothesis. This was done consecutively for each race and sex, using secondary data from 99 of USA largest cities. It was found that only lithium levels are significantly negatively correlated with AHD in whites, and likewise vanadium levels in non-whites. These results are likely to be consistent for both sexes. It is concluded that this finding supports the desirability of further research towards mineral enrichment of the drinking water in certain communities, provided that conclusive evidence of the harmlessness of such enrichment is obtained.