fluoridated water, teas, and some marine fish. Because of the ability of tea leaves to accumulate fluoride to concentrations exceeding 10 mg/100 g dry weight, brewed tea contains fluoride at concentrations ranging from 1 to 6 mg/liter depending on the amount of dry tea used, the water fluoride concentration, and brewing time (Cremer and Buttner, 1970; Wei et al., 1989). The concentrations in decaffeinated teas are approximately twice those of caffeinated teas (Chan and Koh, 1996). Muhler (1970) reported fluoride concentrations in marine fish ranging from 0.6 to 2.7 mg/100 g. The samples, however, may have contained bones. More recent studies reported average fluoride values for fish close to 0.05 mg/100 g and a range of 0.01 to 0.17 mg/100 g (Taves, 1983; Whitford, 1996).

Table 8-2 shows the fluoride concentrations of prepared foods that were served to adult hospital patients (Taves, 1983). When preparation required the use of water (for example, some juices, boiling vegetables), the local water, which contained 1.0 mg/liter fluoride, was used. Nonclassifiable foods included certain soups and puddings. The average daily fluoride intake was 1.8 mg, but intake from drinking water was not taken into account. Other investigators (Filippo and Battistone, 1971; Singer et al., 1980) reported an average intake of fluoride of 2.2 and 1.2 mg/day, respectively.