The Bacteriological Quality assessment of some bottled water sold in Lagos Metropolis, Nigeria

Abstract

This study investigated the bacteriological quality of some bottled water sold in  Lagos metropolis, Nigeria. A total of 30 bottled water samples were used in the  study. The mean pH values ranged from 5.95 to 8.30. All water samples were  subjected to standard bacteriological tests such as Heterotrophic plate count and coliform count and the multiple tube tests (MPN). The mean heterotrophic plate  count ranged from 1.2 x101 to 2.5 x 102 cfu/ml while mean total coliform count  ranged from 0.2 x 101 to 2.0 x 102 cfu/ml. The MPN/100 ml of the samples ranged from < 3 to > 1100 coliforms/ml. Ninety-nine (99) isolates were obtained and the completed test revealed the presence of Escherichia coli (3%) and Enterobacter species (97%). All the bottled water brands did not meet up with the standard  stipulated by the Nigerian Industrial Standard for drinking water quality and the World Health Organization standard. This indicates that some of the bottled  packaged water available in Lagos market may be unfit for human consumption due  to their inability to meet up with the recommended standard by regulatory bodies in Nigeria. Effort needs to be intensified in the monitoring of activities in this rapidly  expanding industry with a view to raising standard and ensuring safety of the  populace.

Keywords: Bottled water, escherichia coli, enterobacter species, MPN, public health.