That many areas of the city get contaminated water even for drinking, is old hat. But a new survey in 92 areas in the city has thrown up startling revelations: in 52 of these 92 areas, the Total Dissolved Solids (TDS) level exceeds the permissible limit of 500 ppm of dissolved solids and chemicals, like fluoride and nitrate. Check this out: water samples analyzed in the 52 areas were found to contain much more than the acceptable level of TDS content i.e. 500 mg/l. TDS refers to the amount of macro minerals, salts or metals dissolved in a given volume of water, and is directly related to the purity of water. The study also found the TDS level crossing the 1,000 mg/l mark in areas like KR Puram, which health experts term a "dangerous sign" . Dr Abhay Kumar, chief scientific officer at the institute that conducted the survey, said many areas where TDS levels are alarming were located in Greater Bangalore region, like Mahadevapura, Banaswadi and Nagawara. Traditional sources of water like municipal supply, lakes etc are failing to meet the rising demand . Indiscriminate sinking of borewells has also contributed to the groundwater table getting polluted alarmingly. The study, where water samples collected from residents were tested, found that in many areas, the level of micro minerals like fluoride and nitrate was also touching the dangerous mark. While the acceptance limit for fluoride in drinking water is 1 mg/l, in outer lying areas of the city like Jalahalli, this chemical level was found closer to the permissible level. Ditto with nitrate, for which the permissible limit in drinking water is 10 Mg/l. Nitrate content was found in abundance not only in the outskirts of the city, but also inner areas like Indiranagar. Nutrition expert KC Raghu said an increase in the intake of certain minerals would lead to imbalance in the functioning of body enzymes. "We call this condition competitive exclusion, wherein certain minerals are forced to be absorbed by the body and could lead to multiple health problems," he added. Raghu said diseases like anaemia, problems to the skeletal structure including teeth and bones, skin problems, and in some cases, serious illness like cancer could also occur. Senior geologist and former deputy director with the mines and geology department N Chandranna said lack of serious efforts to recharge groundwater has led to a deterioration in the quality of groundwater in the city. "With the city fast becoming a concrete jungle and due to unscientific digging of borewells, there is no respect for water. Even if we can recharge 20% of the rainwater Bangalore receives, groundwater problems can be gradually resolved in the coming years," he added. The study was conducted by the Eureka Forbes Institute of Environment. TIMES VIEW That the quality of our drinking water is dipping alarmingly should come as a warning sign to citizens. Polluted water is sure to have a direct impact on our health, and set off complications among a large section of the populace. While it's a fallout of the increasing pressure on our natural resources, it's up to us to work out ways to avert a disaster. The groundwater table needs to be recharged, for which rainwater harvesting is the first step, and the authorities should ensure this in every building. They also need to monitor the quality of water and regulate the indiscriminate digging of borewells.