In work results of cyanobacteria hygienic estimation of lakes of Ukrainian Danube region are presented. The analysis of the literature data has shown that cyanobacteria should be considered as an important factor of negative influence on ecosystems of superficial reservoirs and population health. The global importance of cyanobacteria problem (Aphanizomenon flos-aquae, Synechocystis salina, Spirulina laxissima) is confirmed by their identification both in reservoirs of various regions of the world, and in lakes of Ukrainian Danube. It is proved a necessity of carrying out physiology-hygienic researches for the purpose of estimation of possible biological effects of water of lakes Kagul, Yalpug-Kugurluy, Katlabukh on an organism of laboratory animals.
