Morton Satin comments to World Health Organization on desalination and minerals in drinking water, August 28, 2007

The Salt Institute appreciates the opportunity to comment on the WHO Report WHO/SDE/WSH/07/0? entitled, “Desalination for Safe Water Supply - Guidance for the Health and Environmental Aspects Applicable to Desalination,” Geneva, 2007. This report is the result of an initial request for advice on the mineral reconstitution of desalinated water, a Workshop in Rome in 2003, a Symposium in Baltimore and follow-on Expert Consultation in Washington in 2006.

Water is the most abundant component of the body. Adequate hydration is critical to the maintenance of all body functions. On a normal day we lose 1.5 liters of water through kidney filtration and another 0.750 - 1 liter through the skin transpiration and respiration. The primary function of all drinking water is hydration. While some natural spring waters promote the medicinal benefits of their high mineral content, others publicize the benefits of very low mineral contents, such as reducing the potential for developing kidney stones. The WHO website, (http://www.who.int/mediacentre/factsheets/fs256/en/), states that WHO is unaware of any convincing evidence to support either the benefits or hazards of regularly consuming waters that are either high or low in mineral compounds.

The goal of the series of international consultations and workshops on desalinated water was to improve health, yet the latest report does not provide any evidence that the suggested proposals will yield any beneficial results. Even at the recommended levels of calcium and magnesium, less than 10 percent of the DRI amounts can be obtained from drinking water. Although remineralization of desalinated water is carried out, the choice of buffering materials is based upon cost-effectiveness to ensure the widest availability to all consumers. Just as with fluorides, there are more practical vehicles for delivery of trace mineral nutrients than public water supplies – a good deal of which is used for purposes other than drinking.

For example, the USDA considers food to be the appropriate vehicle for magnesium. A good food source of magnesium contains a substantial amount of magnesium in relation to its calorie content and contributes at least 10 percent of the U.S. Recommended Dietary Allowance (U.S. RDA) for magnesium in a selected serving size. The U.S. RDA for magnesium is 400 milligrams per day.

About 25 percent of the magnesium in diets is supplied by grain products and another 25 percent by fruits and vegetables. Meat, poultry, and fish provided about 18 percent of the magnesium. All of the fats, sweets, and beverages combined supply the remaining 14 percent of the magnesium; however; they have never been put onto the list of "good food sources". The most recent research confirms that food should remain the best vehicle for magnesium delivery^{^[1]}.

With reference to magnesium nutrition, we believe that it would have been prudent for WHO to consult with the Nutrition Division of FAO. In the same Agriculture Department as the Nutrition Division, FAO has a fertilizer group dedicated to soil nutrition and an essential part of its goals focus upon the benefits for human and animal nutrition. Magnesium is an essential soil nutrient in all sustainable agriculture. Had there been a joint WHO/FAO study group and call for better soil management practices, particularly regarding magnesium and calcium fertilization, agricultural yields would increase and, more importantly from a nutritional point of view, there would be an immediate increase in the levels of calcium and magnesium in a very broad range of foods, thus achieving WHO’s goals.

As stated on page 88 of this WHO Report, a very great part of the calcium and magnesium deficiency occurs in the developing world, where agriculture plays an far greater role in nutrient delivery than desalinated water does. Indeed, people in developing countries who have access to high quality water are likely to have access to a more balanced diet and the essential trace minerals that it delivers. The singular WHO approach on magnesium and calcium nutrition in desalinated water does not reflect what should have been the functional synergies to be gained through working together with FAO and other cogent UN sister agencies.

Finally, the CODEX Alimentarius Commission Standard for Bottled/Packaged Water makes direct reference to the WHO Guidelines for Drinking-water Quality. Should these Guidelines be modified, it may severely impact the trade potential for certain products and would likely precipitate a call for a revision to the CODEX Standard. This will allow for a broader examination of this issue by another group of nutritional experts whose conclusions may vary significantly from those of the current report.

[1] Alexandra Kazaks and Judith S Stern (2007) “Overweight and obesity are associated with decreased magnesium intake in people with asthma”, California Agriculture: Vol. 61: No. 3, Page 119. (http://repositories.cdlib.org/cgi/viewcontent.cgi?article=3150&context=anrcs/californiaagriculture)