This study was performed to reduce the import price of sodium fluoride, which accounts for 88.15% of the water fluoridation costs in Korea.
The author examined the propriety and cost-effectiveness of water fluoridation in case of
substituting the sodium fluoride by refined sodium silicofluoride, as a by-product in defluoridated-
phosphate fertilizer industry, and analysed availability of the sodium silicofluoride. The obtained results were as follows:
1. The fluoride compound used in larger cities should be substituted by sodium silicofluoride.
2. If sodium silicofluoride is substituted for sodium fluoride, the purchase price of fluoride in public water fluoridation program will be retrenched by 76 percents without any change of the installation.
3. When the public and subsurface water were fluoridated with the by-product; of domestic fertilizer industry to 1 ppmfluoride, the concentration of F^(-), C1^(-), NO2^(-), Br^(-), NO3^(-), PO4^(3-),
SO4^(2),Li^(+),Na^(+),NH4^(+),K^(+),Mg^(2+),Ca^(2+),Sr^(2+),Ba^(2+),Pb^(2+),Cu^(2+),Cd^(2+),Co^(2+),Zn^(2+),
Ni^(2+), Fe, Si, Al, Ti, Cr, SiO3^(2-) and As were small amounts or not detected, thus both water
passed the water quality standards of Canada, Switzerland,Japan, WHO and Korea, respectively.
4. The availability of domestic sodium silicofluoride is approved, thus a further study for complete confirmation is required.
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