Methods: Territory of Pribaikalie occupies about 800000 sq. km. Here 2 classes of natural landscapes are distinguished, namely taiga (15 different types) and forest-steppe ones. In total 687 water sources were investigated to determine fluorides concentration and water hardness.
Results: Fluorides concentration in all kinds of water sources (surface waters, wells, springs) was 2,5-3 times higher in forest-steppe landscapes than in taiga. A map and a table of fluorides distribution was made up.
Conclusion: The study on the regularities of spatial distribution of fluorides will help to investigate the prevalence of dental caries and fluorosis in Siberia. Distribution of mineral substances is caused by their content in parent matrix, intensity of the elements migration, pH values, etc.