Assessment of microbiological quality of sachet-packaged drinking water in Western Nigeria and its public health significance

SummaryObjectiveTo assess the microbiological quality of sachet-packaged drinking water in Western Nigeria and its impact on public health.Study designCross-sectional microbiological testing.MethodsNinety-two sachet-packaged water samples were analysed for microbiological and metal qualities. Total bacterial and coliform counts were determined, and the presence of Escherichia coli, an important water quality indicator, was tested. The level of conformity of the water processors with the guidelines of Nigeria's quality regulatory agency was also determined.ResultsVarying levels of microbial contamination were recorded in samples from the different sampling locations. The total bacteria count ranged between 2.86 and 3.45 log colony-forming units (cfu)/ml. The highest coliform count recorded was 1.62 log cfu/ml. Faecal coliform E. coli was detected in one sample from Oke-Iho and one sample from Okaka, representing 2.2% of total samples. Lead and manganese were not found in any of the samples. However, iron was detected and the highest iron concentration (0.10 mg/l) was detected in samples from Ikorodu. The bacteria that were identified from the water samples included E. coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella sp., Proteus vulgaris, Alcaligenes faecalis, Bacillus cereus, Staphylococcus aureus, Streptococcus lactis, Aeromonas sp. and Micrococcus luteum. Many of the water processors did not comply with the guidelines of the quality regulatory agency.ConclusionsSome of the sachet-packaged samples of drinking water were of poor quality. The results indicate a need for Nigeria's quality regulatory agency to take appropriate measures in safeguarding public health.