Friday, August 26, 2005

Beware of packaged drinking water: Check out for pathogens, chemical residues

August 26, 2005
By Syed Akbar
Hyderabad, Aug 25: The next time you buy packaged drinking water make it sure that you are not buying harmful bacteria and other pathogens. Most of the packaged drinking water brands available in the market fail one or the other quality test and only a few of them conform to the international standards.
An analysis of six leading packaged water brands including Bisleri, Kinley and Aquafina at the State government-controlled State Food Laboratory showed that some samples were acidic, which simply means that the water is more fit for gardening than drinking or sprinkling over body to reduce pain from intense mosquito bites.
Moreover, some of the samples had relatively high total dissolved solids indicating that the claim of manufactures of employing reverse osmosis methods is bogus. A water sample even had coliform bacteria and aerobic microbial count which shows that the source of water is contaminated with human or animal faeces.
Bisleri water had failed the all-important microbilogical examination
at the State Food Laboratory. The aerobic microbial count (total plate count) should 100 colonies per ml. There were four colonies/ml of Coliform bacteria. However, no E. coli, salmonella, yeast and molds and S aureus were found either in Bisleri or other water samples.
The presence of coliform indicates that the water may be contaminated with human or animal wastes. Pathogens in water cause diarrhoea, cramps, nausea and headaches and may pose a severe health risk for infants and children.
Packaged water bottles of Bisleri, Kinley, Fresh, Aqua God, Aquafina and Manjeera as also municipal tap water filtered through Aquaguard were analysed. Tap water filtered through Aquaguard was found to be safe. The water bottles were purchased from different shops in Secunderabad area.
However, no tests were conducted for the presence of Cryptosporidium, a protozoan parasite commonly present in water bodies. Cryptosporidium tests are not mandatory though bottled water sources often are just as prone to Cryptosporidium contamination as any other drinking water source.
When contacted M Rajendra Prasad, manager of the local Bisleri unit, told this correspondent that he would not make any comment. "I am out of city and will be back on Tuesday. I will comment only after seeing the laboratory report," he said.
Bisleri and Fresh samples showed a pH of 6.83 and 6.9 respectively which in other words means the water is acidic. Drinking water is normally neutral (pH of 7). According to international standards as also those framed by the United States Environment Protection Agency, any water that has a pH of 5.8 to 6.9 is acidic as it contains full of hydrogen ions. Acidic water is good for external use and industrial purposes, but not for long-term human consumption. If consumed the water attracts minerals from the body and cause mineral deficiencies.
Acidic water is also good for plant growth, crops, and livestock as it will help keep a much lower mortality rate and cleaner environment by killing bacteria. It provides excellent relief from mosquito bites.
Bisleri, Kinley, Fresh and Aqua Gold had total dissolved solids of 62 mg/lt, 68 mg/lt, 112 mg/lt and 118 mg/lt respectively while the US Environmental Protection Agency norms indicate that ideal drinking water from reverse osmosis, distillation, deionisation and microfiltration should contain TDS less than 50 mg/lt. The test showed that the claims of several companies on employing reverse osmosis and other filtration methods were hollow and bogus.
Bisleri and Kinley had 10.44 mg/lt and 0.90 mg/lt of nitrates while tap water had just 2.88 mg/lt nitrates. Though all samples except Bisleri had nitrates within the maximum contaminant level of 10 mg/lt, the lesser the nitrates content the good the quality of water. Presence of nitrates in water means contamination from runoff from fertiliser use, leaking from septic tanks, sewage or erosion of natural deposits.
Infants below the age of six months who drink water containing nitrates in excess of MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome.
However, all the samples pass the turbidity, cyanide, mineral oil and fluoride tests. As for as chlorides and sulphates are concerned, even the WHO has not set any standards for these materials.
Except Bisleri, all the samples including tap water were declared "not adulterated" by the State Food Laboratory primarily because they did not contain any pathogens or cyanide.
Of the 358 water samples tested by BIS, 297 passed the quality test and remaining 61 samples failed to meet the required quality norms.
"We have been analysing samples quite regularly. Whenever we find any deviation in quality, we take action including cancellation of licences. If the State Food Lab report mentions about adulteration of water samples, complaint can be lodged with us for further action," Bureau of Indian Standards Hyderabad unit head RS Sarma observed.

Thursday, August 4, 2005

IICT develops mechanism to filter out fluoride content from water

Syed Akbar
Hyderabad, Aug 4: City-based Indian Institute of Chemical Technology has developed a simple but effective mechanism to filter out fluoride content from water in villages affected by fluorosis.
The machine which works on reverse osmosis system provides 600 litres of pure fluroride- and bacteria-free water per hour. A litre of pure water costs less than five paise. It gives out water containing less than 0.5 ppm of fluoride and about 20 ppm of total dissolved solids, which are essential nutrients required by humans, from raw water containing 1200 ppm of TDS.
The IICT has set up a pilot plant in Mylaram village of Nalgonda district at a cost of Rs 3.5 lakh. The rejection of TDS is about 98 per cent and fluoride is 92 per cent. The flux is generally maintained at 25 litres per hour metre cube and quantity of water recovered for drinking is about 65 per cent. The remaining 35 per cent water is the reject for disposal, which can be used for washing of clothes or gardening.
IICT director Dr JS Yadav told reporters on Thursday that Andhra Pradesh had many places with high content of fluoride and people living in these areas were affected by weakening of skeletal and dental framework, knock knee, cataract, low blood pressure and gastro-enteritis. Ground water in Nalgonda contains 20 ppm fluoride as against the permissible level of 1.5 ppm (Indian standards) and 0.5 ppm (WHO standards).
Dr Yadav said current methods such as "Nalgonda Technique", which involve removal of fluoride by adsorption, suffer from disadvantages like poor fluoride removal capacity, inability to separate imputeries (sulphates and micro-organism), low flow rates and high operating costs.