Comparison of the physicochemical and microbiological quality of different brands of bottled water with well water in Lesotho using principal component analysis

Abstract

Water, though vital for life, is also the route for transmission of water-borne diseases. Bottled water is consumed worldwide for its accessibility and the public perception of purity. However, this perception is usually not based on experimental results to confirm or invalidate it, especially where the sample commodity is not adequately tested for quality. In this study, different bottled water brands in Lesotho were compared to tap and well water samples sourced locally. The standard water testing methods were used to assess the physicochemical and microbiological quality of these samples. The physicochemical parameters such as hardness, alkalinity, pH, chloride, conductivity and nitrate content were below WHO acceptable limits for all water samples tested. Upon the employment of multivariate statistics, one of the bottled water samples (C) was completely indistinguishable from the two well water samples collected in the local village. On the other hand, microbiological analysis indicated that the water samples designated as C (bottle water brand), F (tap water), G (Ha-Mafefooane) and H (Roma community water) had a high microbial load and were contaminated with Escherichia coli, while A, B, D and E samples contained Staphylococcus spp. The presence of such indicator organisms suggests possible poor hygiene during processing. It is therefore recommended that stricter policy measures be taken to regularly monitor bottled water quality, before and after production and storage, to fulfil the basic water quality standards of WHO. Public awareness should also be created that bottled water may still be impure, despite appearing attractive and convenient.