Physicochemical and bacteriological quality of bottled drinking water in three sites of Amhara Regional State, Ethiopia.

BACKGROUND: The consumption of bottled drinking water is becoming increasing in Ethiopia. As a result there has been a growing concern about the chemical, physical and bacteriological quality of this product. Studies on the chemical, physical and bacteriological quality of bottled water is quite scarce in Ethiopia. OBJECTIVE: This study was therefore aimed to assess the physicochemical and bacteriological qualities of three factories of bottled drinking water products produced in Amhara region. METHODS: A Laboratory based comparative study was conducted to evaluate the physicochemical and bacteriological quality of three factories of bottled drinking water produced in Amhara region. Analysis on the quality of bottled drinking water from the sources, wholesalers and retailers were made with World Health Organization and Quality and Standards Authority of Ethiopia recommendations. Triplicate samples from three types of bottled drinking water were randomly collected and analyzed from June, 2006 to December, 2006. RESULT: A total of 108 commercial bottled drinking water samples were analyzed. The result showed that except pH of factory A all the physicochemical parameters analyzed were with in the recommended limits. The pH value of factory A tested from sources is 5.3 and from wholesalers and retailers is 5.5 and 5.3, respectively, which is below the normal value set by World Health Organization (6.5-8.0) and Quality and Standards Authority of Ethiopia (6.0-8.5). Our analyses also demonstrated that 2 (16.7%) of the samples tested from sources and 1 (8.3%) from wholesalers of factory B were contaminated with total coliforms, where as 2 (16.7%) samples from retailers were also contaminated with total coliforms. On the other hand, 1 (8.3%) of the samples tested from wholesalers and 2 (16.7%) of the samples tested from retailers of factory A were also contaminated with total coliforms. Total coliforms were not detected from all samples of factory C, fecal coliforms were not also isolated from all samples. Percent of coefficient of variation showed that variations in total coliforms counts were significant with in the samples of both factory A and B (CV > 10%). CONCLUSIONS: Based on the recommended limit of World Health Organization and Quality and Standards Authority of Ethiopia, 7.4% of bottled drinking water sold commercially could be considered unfit for human consumption. Consumers of bottled water should be aware of this.