In 1998 the third investigation of fluoride levels in drinking water from private and public wells (136 samples) was carried out in Volarna village, Kolín district. Results of this investigation were then compared with those a similar survey carried out in 1992 (122 samples) and 1994 (125 samples). In addition, fluoride level in urine of nine schoolchildren of the same village were examined using ion selective electrode (result expressed in umol/l and related to the level of creatinine). Information on hydrogeological conditions prevailing in the locality were obtained form the Water Resources company in Prague. During the survey carried out in 1998 year it was found out that the standard for fluorides (1.5 mg/l) were excceeded in 96 % of the total number drinking water wells examined in the locality. Similar results were obtained during the surveys performed in 1992 and 1994 when the values compared with those of 1998 year, though fluctuating, did not differ significantly. In three urine samples of the levels of fluorides exceeded standard values accepted for fluoride professionally exposed persons (limit 11 umol F/lmmol of creatinine) and reached 11.6, 13.5, and 16.2 umol F/mmol of creatinine. The authors are well aware that the number of urine samples examined is insufficient and shoul be increased in future. As far as the hydrogeological conditions prevailing in the area are concentrated it is presumed that the presence of fluorides in the underground water has its origin in a cenomat collector in the surroundings of Volarna village. Fluorides in the locality are belived to be of natural origin (a washout from the mother rock) and there is no prove that drinking water in the studies locality is po l uted by industrial sources (glass factory). Authors concluded that the study warrants further investigation by Public Health services with the objective to assess the extent of possible environmental risk and to outline remedial measures in the area concerned. In the case of village Volarna construction of connection to the central drinking water supply system would be in their opinion the method of choice.

        Key words: fluorides in drinking water - fluorides in urine - environment - envitonmental risk factors