Experts debated the potential benefits of consuming hard water at the International Symposium on Health Aspects of Calcium and Magnesium in Drinking Water April 24 to 26. It is been theorized that hard water consumption may potentially lower the risk of cardiovascular disease.
Water Quality Association (WQA) Technical Director Joseph F. Harrison, CWS-VI, PE, and WQA Technical Services Consultant Regu Regunathan, PhD, both spoke at the event. The WQA was a sponsor.
Harrison argued that, whatever benefits there may or may not be, the World Health Organization (WHO) should not recommend calcium and magnesium in drinking water for health purposes. He said the benefits of consuming softened, treated water far outweigh any potential benefits of consuming hard, untreated water. Harrison also called for scientists to make a distinction between water that is naturally soft and water that is softened through a water treatment process.
“Naturally soft water actually leaches more contaminants from water distribution lines and plumbing systems into the drinking water supplies. Softened water does not, rather, it removes dangerous and trace level contaminants from water supplies. This major difference between these two types of waters must be taken into account,” Harrison said.
“If users of point-of-use (POU), reverse osmosis water or desalinated water, for example, are advised that they are at risk due to calcium or magnesium deficiencies, the press and free market entrepreneurs will convince residents in naturally soft municipal water systems of the same deficiency and significant risk. Consumer perceptions in central water systems will be affected. The same advisories and policies regarding calcium and magnesium concentrations in demineralized drinking water will be applied to the major central supplies that have naturally low water hardness,” Harrison added.
He cited public water systems such as those in Boston, Portland, Ore., Tacoma, Wash. and San Francisco as those with naturally soft water supplies.
“Any recommended guidance for drinking water hardness will immediately manifest to a broad and influential public health policy. It will affect consumer attitudes toward the safety of their drinking water supplies, and it will significantly direct expenditures of resources toward public health protection. We must insist that the highest levels of evidence be used to guide and set these policies. All of the evidence so far suggests any association between drinking water calcium and/or magnesium levels and human health are observational population studies, and relate only to naturally soft and naturally hard water. They may not pertain or apply at all to the significantly different softened or otherwise treated water supplies,” he concluded.
The information presented at the Symposium now shifts to a WHO expert committee for review. The committee is expected to make any recommendations by year-end.