Microbiological analysis of packaged drinking water sold in Chennai

Abstract

Background: Adequate supply of fresh and clean drinking water is a basic need for all human beings. In terms of public and environmental health, it is essential that water sources be free of pathogenic bacteria and safe to drink. Continuous increase in the sale and indiscriminate consumption of packaged drinking water is of public health significance. In order to safeguard public health it is essential that the available packaged water is of the highest quality. Aims & Objective: The current study was designed to assess the microbial quality of sachet and bottled drinking water sold in retail outlets in Chennai. Materials and Methods: In the present study, fifty one samples including 36 sachet and 15 bottled drinking water samples were analyzed for the presence of bacterial indicators of water quality. Total and faecal coliform count, total viable plate count and culture were performed to determine the identities of the isolates. Results: Of the 36 sachet water samples analysed, 33.3% failed to meet the WHO drinking water standard of zero coliform per 100 ml making them unsuitable for human consumption whereas all the 15 bottled water samples are of better quality. Faecal coliforms were not isolated from any of the sachet or bottled drinking water. The bacteria that were isolated from water samples included Klebsiella pneumonia, Enterobacter aerogenes, Citrobacter freundii, Pseudomonas spp., Acinetobacter spp., Staphylococcus aureus, Coagulase negative Staphylococci, Micrococcus spp. and Bacillus spp. Conclusion: The bottled water samples analyzed are of better microbiological quality when compared to that of the local brands of sachet water samples. The findings therefore suggests that these sachet water are not fit for human consumption and are hazardous to health. Hence there is a need for strict and routine monitoring of the packaged drinking water with the view of raising their standards.