wAbstract
@The inorganic chemistry of 85 samples of bottled natural mineral
waters and spring waters has been investigated from 67 source
across the British Isles (England, Wales, Scotland, Northern Ireland,
Republic of Ireland). Sources include boreholes, springs and wells.
Waters are from a diverse range of aquifer lithologies and are
disproportionately derived from comparatively minor aquifers,
the most represented being Lower Palaeozoic (10 sources), Devonian
Sandstone (10 sources) and Carboniferous Limestone (9 sources).
The waters show correspondingly variable major-ion compositions,
ranging from Ca-HCO3, through mixed-cation-mixed-anion
to Na-HCO3 types.Concentrations of total
dissolved solids are mostly low to very low (range 58-800 mg/L).
All samples analysed in the study had concentrations of inorganic
constituents well within the limits for compliance with European
and national standards for bottled waters. Concentrations of NO3-N reached up to half the limit of 11.3 mg/L,
although 62 of samples had concentrations1 mg/L. Concentrations
of Ba were high (up to 1010Κg/L) in two spring water samples.
Such concentrations would have been non-compliant had they been
classed as natural mineral waters, although no limit exists for
Ba in European bottled spring water. In addition, though no European
limit exists for U in bottled water, should a limit commensurate
with the current WHO provisional guideline value for U in drinking
water (15Κg/L) be introduced in the future, a small number of
groundwater sources would have concentrations close to this value.
Two sources had groundwater U concentrations10Κg/L, both being
from the Welsh Devonian Sandstone. The highest observed U concentration
was 13.6Κg/L.
@Solute concentrations in waters contained in glass bottles compared
with waters in PET showed slightly though significantly higher
concentrations of Al, Ce, Cu, La, Nd, Mn, Sn, W, Zn and Zr (rank-sum
testing, p0.05). By contrast, Sb concentrations were significantly
higher (p0.001) in samples contained in PET bottles. This accords
with other studies that have recognised Sb contamination in water
from PET bottles. However, in no cases did the concentration of
Sb exceed or approach the national and European limit for Sb in
natural mineral water/spring water (5Κg/L), the highest observation
being 1.35Κg/L.
@Bottled water compositions were mostly similar in their major-ion
characteristics to raw groundwaters from the equivalent aquifers
in Britain, although concentrations of several trace elements
(Al, Cd, Cu, Fe, Mn, Pb and Zn) were appreciably lower, in some
cases by one or two orders of magnitude. The most likely mechanism
for the reduction is use of aeration, settling and filtration
to remove unstable constituents before bottling. The comparatively
low concentrations of Cd, Cu, Pb and Zn are likely to be due to
co-precipitation with/adsorption to precipitated metal oxides,
although choice of resilient pipework (e.g. stainless steel) in
bottling plants may also be a factor. although for the most part
the major ions in the bottled waters appear representative of
the groundwater in their host aquifers, the results suggest that
many of the trace elements have been modified significantly from
natural composition in situ.x
1. Introduction
2. Bottled waters in the British Isles
3. Sample collection and analysis
4. Results
@4.1. Chemical compositions
@4.2. Compliance in inorganic water quality
@4.3. Compositions in relation to bottle type
@4.4. Compositions related to regional geological control
@4.5. Compositions compared to British groundwater chemistry
5. Discussion and conclusions
Acknowledgements
Appendix A. Supplementary material
References