An assessment of the potability of some sachet water brands sold in Cameroon
Analysis of the microbial and physico-chemical qualities of 14 sachet water brands sold in Cameroon was carried out aimed at determining their potability based on World Health Organization (WHO) recommendations. Similar analyses of water samples from the respective sources were used to compare the quality of the water at source and in the sachets in an attempt to identify potential sources of contaminants in each sachet where appropriate. The most probable number method was used to determine the total coliforms in the water while eosine methylene blue (EMB) agar was used for the detection of faecal coliforms and to differentiate Escherichia coli from other gram-negative pathogens present in the water samples that showed the presence of coliforms. The physical parameters examined were pH, electrical conductivity (EC), and the total dissolved solids (TDS) using a ++WTW 315i pH meter and a Cond 330i/set, while total suspended solids (TSS) were determined by filtration, and alkalinity determined by titration using hydrochloric acid. The following major ions were determined using ion chromatography: Na+, K+, Mg2+, Ca2+, F-, Cl-, NO3 -, PO43-, SO42-and HCO3 -. The results indicated that the pH, TSS, EC, TDS fell within the WHO limits for potable water. The main water types were Ca-Mg-HCO3, Na-KSO 4-Cl and Na-K-HCO3 with 50% of the samples clustered in the Ca-Mg-HCO3 zone and the rest in the Na-K-SO4-Cl (30%) and in the Na-K-HCO3 (20%) zones. The major ions in all water samples were Na+, K+, Mg2+, Ca2+, Cl- and HCO3 - and their presence was shown to be primarily attributable to the natural geological conditions of the water sources. Although results of the physico-chemical analyses were indicative of acceptable limits for potability, the results of microbial analysis indicated that about 85 % of the brands tested were microbially unsuitable for consumption. The health implications of these results call for further assessment of the policy and management of the sachet water industry in the country.
Key words: sachet water, potability, physico-chemical, microbial, quality.