Bacteriological quality of bottled water sold on the Ghanaian market

Abstract

Consumption of bottled water is increasing rapidly in developing countries especially among the middle and high income earners as it is generally perceived to be pure, clean and of good quality. This has led to the sale of different brands of bottled water on the Ghanaian market. Although disease outbreaks due to contaminated bottled water are rare, any contamination may pose a unique hazard because of the widespread distribution. Bacteriological contamination of bottled water can occurthrough the bottling process or as a result of storage for long periods at room temperatures or higher. Since bottled water may be consumed by a wide range of people including the elderly, children and pregnant women, its safety must always be assured. The bacteriological quality of the current 7 brands of bottled water on the Ghanaian market was tested over a period of 10 weeks. Ten different batches of each brand was randomly selected and purchased from the market making a total of 70 samples. Sampling was done weekly in July-September 2007 and bacteriologicalexamination conducted by multiple tube fermentation method to detect the presence of total coliforms, faecal coliforms and Escherichia coli. Results obtained were analyzed according to the World Health Organization (WHO) standards and guidelines for drinking water. Using the Most Probable Number (MPN) Index for various combination of positive and negative results, an MPN value of less than two (