Abstract:
The global prevalence of diseases is heavily impacted by the consumption of unsafe drinking
water. In Low- and Middle-Income Countries (LMIC), bottled drinking water is among the
fastest growing options for seemingly safe drinking water. Convenience and perceived good
quality are leading motivators of bottle water use in LMICs, however water quality
information for bottled water brands in LMICs remain scarce. The objective of this study
was to assess the physico-chemical and microbial quality of bottled drinking water in
Embakasi Central Sub-County, Nairobi County, where elevated levels of diarrheal diseases
have been documented in recent years. Using a cross-sectional study design, the study
assessed 8 commonly consumed bottled water brands purchased from local retail outlets,
consisting of 158 water samples collected in duplicate. Laboratory analysis was conducted
to assess pH, electrical conductivity, lead, nitrite, nitrate, fluoride, heterotropic plate count
(HPC), E. coli, total dissolved solids (TDS), hardness, sulphate, sodium, magnesium,
potassium, and calcium. Across all brands, 12% of samples exceeded the national water
quality guideline for microbial safety (<1 CFU E.coli/100 mL). Select brands were
frequently contaminated with E. coli, with Brands 2 and 5 having 28% and 30%
contamination rates, respectively. Additionally, 100% of Brand 5 samples had unsafe levels
of fluoride. Overall, one in five samples collected exceeded the accepted thresholds for
contaminants of public health concern (fluoride or E. coli). The results of this study reveal
poor quality of bottled drinking water in a suburb of Nairobi, presenting a risk to consumers.
There is a need to strengthen risk management and oversight of water packaging facilities in
this setting.
