Bottled Water Contaminants
There is currently a medical controversy over what effect, if any, drinking hard or soft water may have on heart disease. Evidently, in some areas with naturally soft water, residents seem to suffer more from heart disease. In other areas, there appears to be no difference between drinking hard and soft water. A number of researchers feel that some other constituent of water -- not hardness or softness may be responsible for the variations in heart disease figures in different areas of the country.
Some researchers believe that very small amounts of a "protective" substance may be present in some water supplies and lacking in others. This unknown substance could have a beneficial effect on the heart in much the same way that minute amounts of fluoride protect the teeth. At the present time, no one knows exactly what this substance may be. Other scientists feel that the problem might be caused by other elements, such as cadmium, in the drinking water. It is known that this metal can cause high blood pressure when taken in small quantities. Trace amounts of cadmium can be dissolved from galvanized water pipes by the corrosive action of naturally soft water.
Over the years many studies have been published on the relationship between drinking water and cardiovascular mortality. Two beneficial factors continually stand out -hardness and total dissolved solids. Both have been associated with lower mortality from heart disease. Hardness refers to the amount of calcium and magnesium, or calcium carbonate in the water. The more calcium carbonate, the harder the water; the less, the softer the water. The first major study on drinking water and heart disease was in 1960 by Schroeder. In his paper, "Relation Between Mortality from Cardiovascular Disease and Treated water Supplies,' the water in 163 largest cities in the United States was analyzed for 21 constituents and correlated to heart disease.