Sir: For quite some time, there has been an ever-growing trend of drinking bottled mineral water in homes, government offices , business concerns, weddings and other functions. Recently, the prices of bottled mineral water have been increased to almost the level of soft drinks. Just imagine, a glass of plain water now costs around eight rupees, if not more. However, just how safe, hygienic and natural is the bottled mineral water that is being used all over? I have raised this pertinent question after recently watching a demonstration in a business house in Lahore. There were three water filled glasses. One contained tap water, the other mineral water and the third contained water that had been passed through the imported water filtration plant, which could be used in houses, offices, and business and commercial premises. Sometime after the chemical tester drops were put in each of these glasses, the colour of the glass containing mineral water changed, indicating that it contained some acid. Tap water is treated with chlorine to make it worthy for human consumption and it showed whereas the colour of the third glass, which had water produced by the filter plant, did not change at all and tasted just like natural water — hygienic, neat and clean. On my query, I was told that the water testing drops are available from medical stores and that anyone could carry out such tests at home or in the office to find out how hygienic, natural and safe bottled mineral water really is. The imported water filter plant may appear a bit costly but this one time investment is still cheaper when compared to the cost of precious human lives being exposed to various ailments through the use of unhygienic and unnatural acids in the treated water. The users and consumers of bottled mineral water can themselves find out about what they are drinking by carrying out such a test to see just how safe, healthy and hygienic the water really is. This is something all of us are drinking daily. I am ready for any correction in this regard although I am pretty convinced that after boiling tap water before use, the water passed through the filter plant is the safest, healthiest and most hygienic with a natural taste. ASMAAR BILAL SHAIKH Lahore