Soft Water - Hard Arteries: An Interpretation of Ecologic Findings.
NIOSH 1985 May:17 pages
An association between the composition of drinking water and cardiovascular diseases was reviewed. In the United States, it was shown in 1956 that the South Atlantic states had a high rate of death due to cardiovascular diseases while the central portion of the country had much lower rates. Several large prospective studies later confirmed that the place of residence is a major risk factor, and drinking water was directly implicated when a Japanese study showed that the death rates from stroke were significantly correlated with the acidity of the local river water. An American study, which has been confirmed in several other investigations, later concluded that the risk of dying from coronary heart disease was approximately 15 percent higher in communities with soft water than in those with hard water. Some other studies have failed to find a correlation. It is pointed out that water quality may be only partially relevant to the fluid intake since many individuals do not drink very much water. Other risk factors also should be considered: age, white race, male sex, cigarette smoking, high blood pressure, and an elevated blood cholesterol level. Most ecological studies have relied on correlation coefficients, but it is pointed out that the regression coefficient is a better indicator of the strength of an association. The author concludes that ecological studies are weak sources of evidence and that stronger evidence of an association between water quality and coronary disease is needed.
Cardiovascular-disease; Drinking-water; Water-analysis; Potable-water; Epidemiology; Ecological-systems; Biostatistics; Humans; Metallic-minerals;
Proceedings of a Symposium on Epidemiology and Health Risk Assessment, Columbia, Maryland, May 14-16, 1985, Centers for Disease Control/NIOSH, 17 pages, 16 references