Message in a Bottle

Water is the only component of our diet that provides no nutrients, yet is essential for growth and maintenance of our bodies. Some decades ...

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Water is the only component of our diet that provides no nutrients, yet is essential for growth and maintenance of our bodies. Some decades ago, the availability of tap water was considered a boon to healthcare, but the impurities and contaminants that come with it have forced people to settle for packaged water. Now the question is: How safe is the water in the bottle?

Why do we need water?

About 50-70 per cent of our body weight is composed of water. Deprived of it, dehydration would be a matter of hours, and survival a matter of days. The amount necessary, though, varies from person to person. While the recommended allowance for an adult is 2.5 litres, in tropical summers, it can go up to 5 litres. While all drinks are water based, for maximum benefit to the body, stick to plain water.

Is plain water okay for drinking?

In India, it’s much safer to boil and filter tap water for drinking. Alternatively, doctors recommend uncontaminated packaged water. ‘‘Bottled water, like all other foods regulated by the FDA, must be processed, packaged, shipped and stored in a safe and sanitary manner and be truthfully and accurately labelled,’’ says Dr Anupam Sibal, consultant gastroenterologist at Indraprastha Apollo Hospital, New Delhi. ‘‘Bottled water products must also meet specific FDA quality standards for contaminants. Though it cannot be 100 per cent free of contaminants, they have to be below the permissible levels.’’

What are the likely contaminants?

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* Aesthetic contaminants affect the taste, odour or colour of the water. They include inorganic elements like iron, manganese, zinc, chloride, sulfate and flouride

* Inorganic elements like arsenic, barium, beryllium, cadmium, chromium, lead, mercury and some nitrates, when present in water, can impact health

* Herbicides and pesticides, too, can creep into water.

* Coliform bacteria, which do not cause diseases themselves, but indicate the presence of other organisms that do

Is bottled water distinct from disinfected tap water?

Municipalities and private water utilities both use chlorine as a disinfectant. Bottled water, on the other hand, is disinfected by ozone or ultraviolet rays.

Is all bottled water safe for consumption?

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Before buying, look for certification and content specifics in mineral water. ‘‘Mineral water comes from protected underground sources and flows over rocks and picks up minerals before being collected. Bottled water is usually demineralised well water, which is processed for softening and subjected to reverse osmosis to make it bacteria-free. It is safe in comparison to municipal water,’’ says Dr S K Sama, chairman and head of department of Gastroenterology at Sir Ganga Ram Hospital.

According to the FDA, mineral water bottles have to clearly list the level of each mineral. ‘‘A high level of sodium can increase the risk of cardiovascular problems, while more flouride can cause fluorosis. Lead, arsenic and copper contamination can lead to toxicity of liver, brain and intestine,’’ says Dr Sibal.