How safe is the safe water supply?

摘要

A total of 1200 drinking water samples from various water sources in Amritsar district, were analyzed to assess bacteriological quality of water. Presumptive coliform count by multiple tube test was done. The study revealed that 570 (47.5%) samples were unfit for human consumption. Of all the samples tested, 63/110(57.3%) samples from religious places, 28/56(50%) from hospitals, 25/50(50%) from bus stands/railway stations, 84/190(44.4%) from schools, 32/100(32%) from BSF checkposts, 5/19(26.5%) from hotels and 3/25(12%) from ice factories were found to be unsatisfactory. Out of the 570 unsatisfactory samples detected, 72% samples from submersible pumps,50% from hand pumps, 45.4% from taps,29.2% from tube wells and 28.5% from domestic tap supply were found to be contaminated. On Eijkman test 20/25(80%) of the suspicious samples turned out to be unsatisfactory. So, availability of safe drinking water still remains a much sought after commodity for majority of public in developing countries like India. Source of support: Govt. of Punjab (India) Introduction Water, the elixir of life is getting polluted due to rapidly increasing population, urbanization, construction of new buildings and deforestation. Water pollution is becoming a global problem threatening human existence .Water contamination occurs from human, animal and industrial wastes mixing into it. They contain a variety of bacterial, viral, protozoan pathogens and helminth parasites along with chemical pollutants. Consumption of such unsafe drinking water may expose a high proportion of the community to the risk of outbreaks of intestinal and other infectious diseases (1) .In fact, more people would die of consuming unsafe drinking water and unsanitary conditions by the year 2020 than from AIDS, if steps to improve water quality are not taken on war footing (2) Ideally, drinking water should not contain any micro organisms which are known to be pathogenic. It should be free from bacteria indicative of faecal pollution. The primary bacterial indicator recommended for this purpose is the coliform group of organisms (3) In themselves, coliforms are not dangerous but their presence indicates that the fecal matter has entered the water supply, and fecal bacteria have not been removed or killed by the purification processes. Therefore the water supply is liable to contamination with dangerous intestinal pathogens (4) So, in the interest of public health water supplies (piped/unpiped) and samples from distribution sources must be checked from time to time to ensure that safe quality drinking water is supplied to the public (5). In fact, much of the ill health which affects humanity especially in developing countries can be traced back to lack of safe and wholesome water supply. There can be no state of positive health and well being without safe water (2). The present study was therefore undertaken to analyse the water samples from various sources for the presence of coliforms. Aims/Objectives The present study was conducted with the objective of assessing the bacteriological quality of water in different drinking water sources in Amritsar District (India). Materials And Methods A total of 1200 drinking water samples from taps of piped supply (550), hand pumps (380),submersible pumps (125 ),tube well(120) and ice factories (25)from various places in Amritsar district received during the period of Jan 2007 to Dec,2008 were analyzed in Microbiology Department of Govt. Medical College, Amritsar.The samples were received in sterilized, standard, specified glass bottles of 230 cc capacity along with properly filled prescribed proforma. The samples were received, stored (in case of delay) and processed in accordance with the guidelines described in standard methods (6). Presumptive coliform count test based on multiple tube fermentation method by Senior BW was used to estimate the most probable number of coliform organisms in 100 ml of water for diagnosis of bacteriological contamina