Urinary fluoride levels after consumption of fluoride-poor drinking waters in Hungary.

Fluoride concentration in the urine of subjects drinking fluoride-poor water was investigated. In the first series of experiments, mean F concentration in the urine collected for 24 hours was 0.26 mg/litre, in the second series, 0.28 mg/litre, and in group fractions 0.20 mg/litre. Standard deviations ranged from 0.07 to 0.12 mg/litre. No conclusion could be drawn from the F level of a single urine fraction to the 24-hour F level of the same subject. In group tests, means reflected the expected 24-hour values. There were differences in the urinary F levels of the subjects. Values for the same subject also varied; they were different on different days and the fractions collected on the same day showed variations. Older people excreted more fluoride than young ones. These findings are in good agreement with published data.