We refer to your report headlined, 'Distilled water can pose risk for hikers' (Sunday Morning Post, September 26). We are happy to offer some further information about bottled water.
Distilled water is the purest and the safest water on the market today. Watson's employs a number of processes to prepare its own water, beginning with multi-filtration pre-treatments.
This is followed by boiling the water at 105 degrees centigrade, then sterilising it and, finally, bottling it. The point of this expensive and time-consuming process is, of course, to guarantee the purity of the product, something of increasing importance in an increasingly polluted environment. Mineral water is extracted from the ground, which, by government regulation, must be located at a significant distance from urban areas as part of the effort to ensure water purity. Sadly, a number of product recalls suggest that risks nonetheless remain.
Even trace amounts of certain minerals can be dangerous. A number of countries have become increasingly concerned, for example, about levels in bottled water of arsenic, a carcinogen, and nitrites, which can affect brain development in children.
Even sodium, a less dangerous mineral, but which is usually found in bottled water, has been correlated with high blood pressure. Mandated daily sodium requirement is only 500 milligrams, but average daily intake hovers somewhere between six and seven grams. You probably do not want more sodium in your water.
With regard to so-called 'good' minerals, bottled water has either too few or none at all, making it unable to supply daily requirements.
Because the term 'mineral water' can be misleading and is often misused, the US Government requires water with very low mineral content to be labelled 'spring water'.
Clearly, a balanced diet is the only way to satisfy the body's need for minerals. Water, regardless of its type, cannot and should not be treated as a remedy for an otherwise poor diet.
EDMOND TSUI Director and General Manager Watson's Water