Abstract:
Fluoride is considered as a double edged weapon as in correct dosage
it strengthens the enamel to prevent dental caries and in excess causes
ugly brown stains of the teeth called dental fluorosis. Drinking water with
high fluoride content has been the main reason for development of fluorosis,
but food items may also contribute in areas with high concentration of
fluoride in soil and water. The purpose of this study was to assess the fluoride
content in tea liquor and identify low cost efficient defluoridating materials
to remove excess fluoride in drinking water.
Fluoride content in tea liquor obtained from eleven brands of low
grown tea and six brands of tea available in the market including green tea
were determined. The fluoride content was found to increase with increase
in brewing time for all types of tea. Market available tea showed higher
levels of fluoride in tea liquor compared to low grown tea. Green tea showed
the highest level of fluoride in tea liquor (0.19 mg).
Detluoridating ability of clay pots, asbestos, granite and ceramic powder
was also examined. With clay pots, optimum fluoride concentration
that can be tolerated is around 2.5 mg dm' Of the three filtering media
namely asbestos, granite and ceramic powder, asbestos showed the highest
exchange and breakthrough capacities. Asbestos appears to be the best
defluoridating material reported to date.
