Packaged natural mineral water is safer and healthier to consume even though it is more expensive, says Dr Saurabh Arora
Did you know that the ‘packaged mineral water’ that you buy on railway platforms, in restaurants or from roadside vendors may not actually be mineral waterIJ It could be just plain packaged drinking water. Most people think that all bottled water is the same but there is a difference. There are two types of water that is bottled; one is Packaged Drinking Water and the other is Packaged Natural Mineral Water. There is a difference between the two because they come from different sources and both types have different standards for purification of the water.
The source of mineral water is natural and therefore it can actually be labelled “Natural Mineral Water.” Natural source means that the water has been obtained directly from natural sources like lakes, rivers or drilled from underground water-bearing strata, spring water that is free from pollutants. Mineral salts and trace elements are the same as present at the source. It is not treated chemically and is packaged hygienically close to the source of water. The mineral content in this type of water is not disturbed and the water is permitted to only go through mechanical filtration which does not change the composition of the source water. Natural Mineral Water is free from contaminants and poses no danger and since it is packaged close to the source it is also therefore more expensive than Packaged Drinking Water.
Packaged Drinking Water on the other hand is obtained from potable water in taps, ground water like bore-well, and public drinking water systems such as Municipality Supply. It can be demineralised and disinfected so it is safe to drink and it also contains minerals that have been added artificially. Packaged drinking water could be treated with processes like decantation or various types of permitted filtration. The testing for this type of water is more detailed as besides impurities it is tested for contaminants including pesticide residues and heavy metals that are often present in ground water.
In a tropical country like India, the minimum water requirement for an average adult human who weighs around 64 kg is approximately six litres per day (WHO, 2004). This equates to over 153,000 litres of water consumed in a lifetime (70 years) for an average adult. You can imagine that if these 153,000 litres contain even a minute amount of contaminants like pesticide residues or heavy metals or toxic anions they can accumulate in the body and cause very serious diseases in the long-term, including cancer. Besides the potential to cause chronic diseases, contamination of drinking water with pathogenic microorganisms can cause a number of short term waterborne diseases, some of which might be acute. Therefore, regular drinking water purification and testing can go a long way to improve the quality of life and save both direct and indirect health costs.
Nowadays, packaged drinking water is purified by reverse osmosis (RO) coupled with UV irradiation to meet the prescribed standards and is bottled prior to distribution. It is also disinfected to a level that will not lead to harmful contamination in the drinking water. However, in case of Packaged Natural Mineral Water, the sourced water is not subjected to processes like RO, demineralisation or disinfection before packaging (BIS Manual for Packaged Water, Third Issue March, 2013).
The general chemical parameters that are tested include ammoniacal nitrogen, anionic surface active agents, total hardness, alkalinity, residual free chlorine and chloramines, various metallic and non-metallic ions, total solids and mineral oil. The water is also tested for toxic substances such as pesticide residues, polychlorinated biphenyls and poly-aromatic hydrocarbons. The toxic heavy metals like lead, arsenic, cadmium, chromium, mercury, selenium are also tested by methods such as Atomic Absorption Spectroscopy (AAS)and Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
From the foregoing discussion, it is evident that when a safe water supply system is not available then “Packaged Natural Mineral Water” is safer and healthier to consume even though it is more expensive. Packaged Drinking Water has flooded the Indian market in recent years and all of it might not be safe. Remember that bottled drinking water without BIS certification is not safe to drink. Moreover, if you are in doubt about the water quality, it is advisable to get a sample tested from a FSSAI notified/NABl accredited laboratory in order to put your fears to rest.
(The author is the founder of Food Safety Helpline)