Drinking water quality and sudden death: observations from West and East Finland.

Relationships of drinking water quality to CHD and sudden death were studied in two rural areas in western and eastern Finland. In the eastern area, drinking water is particularly soft and contains less magnesium and chromium but more copper than in the western area. A 15-year follow-up of resident males showed a higher death rate from CHD in the eastern area but no difference in the proportion of sudden deaths. The data suggest that CHD may be associated with low concentrations of magnesium and chromium in the drinking water, but no definite relationship was found between water quality and sudden death.