[Characteristics of drinking water and coronary heart disease. An epidemiological experience (author's transl)].

Mortality for coronary heart disease (CHD) in two samples of men aged 40-59 at entry was rather different after the first 5 year follow-up, but became more and more similar - and substancially identical - after 15 year follow-up. In the community which showed the greatest relative increase of CHD mortality beyond the fifth year, a drastic change in the characteristics of drinking water had occurred, with a large reduction of hardness, and of calcium and magnesium concentration.