Based on data of the district hygiene station in Kolín on the high natural fluoride concentration in wells in the community of Volárna, the authors evaluated the health risk of dental and bone fluorosis for the population of the community resulting from increased exposure to fluorides from drinking water. For evaluation of the risk the methodical instructions of the chief hygiene officer of the CR were used and methodical procedures of US EPA. The authors evaluate the danger of fluorides and relationship of the dose and effect based on epidemio- logical studies. They used reference doses from the IRIS US EPA database. For calculation of the mean daily fluoride dose in relation to the risk of dental fluorosis in children it was best to select the most risky period of early mineralization of teeth during the first two years of life. The authors confirmed the existing risk of dental fluorosis of a mild to severe grade, depending on the actual fluoride concentration in the well, for all children in the community andthe existing riskof the third disabling stage of bonefluorosis in roughly one quarter of the adult population of the community. The authors discuss the doubts associated with evaluation of the risk.

        Key words: fluorides in drinking water - evaluation of health risk - fluorosis