Hydrogeochemical characteristics of some Cameroon bottled waters, investigated by multivariate statistical analyses

In this study, 8 bottled water brands sold in Cameroon were analyzed for 76 elements/parameters by ICP-MS, IC, titration and mass spectrometric methods. This was to investigate the geochemical characteristics of the bottled waters in order to identify the main hydro geochemical processes controlling their chemical content. A comparison of the element concentrations and the legal limits for both bottled and tap water (Cameroon, EU, US EPA, WHO) shows that Aluminium concentration in three brands is above the lower guideline value set by EPA with very high lead concentration (6.4 μg/l) in one brand. Various water quality classification systems were used in to characterize the different bottled water types. Piper diagram was used to establish that dominant chemical types of the bottled water brands are Ca–HCO3, Ca–Mg–HCO3, Ca–Na–Mg–HCO3, Na–HCO3 and Na–Mg–HCO3. Application of R-Mode factor analysis to the data set allowed the determination of the possible relationship between the distribution of individual elements and lithology or other surface enrichment phenomena. In particular waters draining through volcanic rocks are enriched in elements such as As, B, Br−, Cl−, Cs, F, K, Li, Na, NO3−, PO43−, Rb, Sc, SiO2, Sr, Te, Ti, and V. One of the three R-Mode factor analysis associations, recognized as being representative of elements analyzed shows high nitrate and Pb loadings along with As, PO43− and Zn. The latter association probably reflects a sign of anthropogenic contribution in the volcano-sedimentary aquifers of the study area. Q-Mode hierarchical cluster analysis established four major groups amongst the bottled water brands. Stable water isotopes (δD and δO18) established that the recharge origin of the bottled waters and other groundwaters of the study area is meteoric.

► Wide diversity of bottled water brands in terms of physico-chemical, chemical quality and stable isotopic content. ► Many elements, even the major ones, show very large natural variations and reflect local geological settings. ► The bottled water brands are of bicarbonate Ca–Mg–HCO3 type though, Na and Na–Mg waters also exist. ► Factor analysis and Hierarchical cluster analysis clarified the complex relationships among the elements and parameters. ► δD and δO18 established the meteoric origin of bottled waters and other groundwaters of the study area.