ABSTRACT
Objective To observe the absorption, excretion and retention of fluoride and aluminum after drinking brick tea in healthy adults. Methods The study was conducted in ten healthy volunteers by drinking brick tea solution in which the fluoride and aluminum concentrations were 5.97, 7.53 mg/L, respectively. The concentrations of fluoride and aluminum were determined in serum samples collected before and at 0.5,1.0,2.0,3.0,and 24.0 h, and in urine samples collected before and during the periods 1.0,2.0,4.0, ＞ 4.0 - ＜ 24.0 h and 24 h after drinking brick tea solution by ion-selective electrode, inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma atomic mess spectrometry. The total amounts of intake and excretion of fluoride and aluminum in healthy volunteers during 24.0 h were calculated from their corresponding fluoride and aluminum ingesting from brick tea and excreting from urine. Results Before and during the periods 1.0,2.0,4.0,＞ 4.0 - ＜ 24.0 h and 24.0 h after drinking brick tea solution, the urinary fluoride concentrations were (0.50 ±0.14), (2.14 ± 0.90), (1.57 ± 0.93), (2.43 ± 1.49), (1.91 ± 0.69), (0.58 ± 0.20)mg/L, respectively, and the aluminum concentrations in the urine samples were (0.35 ± 0.15), (0.65 ± 0.37), (0.50 ± 0.25), (0.52 ± 0.21 ),(0.50 ± 0.23), (0,46 ± 0.27)mg/L, respectively; the 24.0 h excreting rates of fluoride and aluminum from urine were 52.90%(4.64/8.77) and 12.38% (1.37/11.07), respectively. The fluoride concentrations in serum samples collected before and at 0.5,1.0,2.0,3.0,24.0 h after drinking brick tea solution were (0.06 ± 0.02), (0.14 ± 0.01 ), (0.21 ±0.04), (0.17 ± 0.04), (0.10 ± 0.03), (0.04 ± 0.01 )mg/L, respectively, and aluminum in those were (0.30 ± 0.05),(0.27 ± 0.01 ), (0.30 ± 0.12), (0.34 ± 0.19), (0.30 ± 0.10), (0.27 ± 0.09)mg/L, respectively. Conclusions Fluoride in brick tea is easyly to be absorbed and excreted through kidney, and the kidney excretory capacity of aluminum in brick tea is limited. Levels of fluoride and aluminum in urine could be taken as the indicators for monitoring the prevalent extent and evaluating preventive experiment's effect on the brick tea fluoride-aluminum toxicity; and fasting serum fluoride and aluminum levels could be taken as indicators for estimating the toxic condition of the brick tea fluoride-aluminum toxicity.