Abstract
Analysis of 25 brands of commercial bottled water and 21 brands of canned tea was carried out to obtain information on their fluoride concentrations. In 13 of 17 domestic Japanese brands of bottled water, fluoride concentration was less than 0.1ppm, and the maximum value was 0.76ppm. In 4 of 8 imported brands of bottled water, fluoride concentration was less than 0.1ppm, and the maximum value was 0.70ppm. In domestic bottled water, Ca content was 1.14-58.81mg/l; and Mg content was 0.70-7.93mg/l. In imported bottled water, Ca content was 8.13-88.78 mg/l; and Mg content was 1.07-25.86 mg/l. Several kinds of tea and other infusion beverages were investigated. Fluoride concentration was highest in the coarse tea called ban-cha: 1.29ppm. In green tea, it was 0.53-0.90ppm. In oolong tea, it was 0.75-1.50ppm. In black tea, it was 0.47-2.19 pm. In barley tea and the infusion known as duzhong tea, it was less than 0.1ppm. These results clearly show that the amount of fluoride and other minerals in bottled water and canned infusion beverages differ from brand to brand. Further clarification of the ingredients of these beverages is needed to determine their efficacy as sources of fluoride and minerals.
