Cyanobacteria and cyanotoxins in water sources – a threat to public water safety

Introduction. Massive algal blooms typical of all climatic zones of the Russian Federation are observed in all federal districts. The greatest danger is posed by the rapid proliferation of cyanobacteria (CB), whose life cycle and death release highly hazardous cyanotoxins into the water.The purpose - hygienic assessment of contamination of Moscow, Chelyabinsk, and Rostov-on-Don surface sources of drinking and domestic water with CB and cyanotoxins and the development of preventive measures aimed at reducing the risk to public health.Materials and methods. The objects of the study were CB and cyanotoxins (microcystin-LR, anatoxin-a, cylindrospermopsin, β-N-methylamino-1-alanine (BMAA), saxitoxin), investigated in surface water sources in the cities of Moscow, Chelyabinsk, and Rostov-on-Don. Theoretical and empirical methods of scientific systems analysis were used. Data from domestic and foreign scientific literature were searched and summarized from the MedLine/PubMed/PubChem, Scopus, and eLIBRARY scientific publication databases, the results of industrial control of water supply institutions, and own chemical analytical and toxicological studies.Results. Regional patterns in the quantitative composition and intraspecific differentiation of toxic cyanobacteria species in surface water sources located in different climatic zones were identified. A hygienic assessment of cyanotic contamination of water sources and the effectiveness of drinking water treatment were conducted. In addition to the current MAC for microcystin-LR (SanPiN 1.2.3685–21), MACs for anatoxin-a, cylindrospermopsin, and BMAA produced by priority types of CB in water sources in the Russian Federation have been substantiated. An algorithm for current monitoring of water pollution with CB and cyanotoxins has been developed, and preventive measures aimed at reducing the risk to public health from drinking water pollution with cyanotoxins have been proposed.Limitations. The lack of domestic standards and test systems that allow testing the content of priority cyanotoxins in water with the required reliability of results.Conclusion. Most surface water sources in the Russian Federation are subject to anthropogenic and, in recent years, climatic influences, creating favorable conditions for the widespread development of CB. The latter, in turn, adversly impacts the quality and safety of drinking water and requires the development and implementation of methodological recommendations for the prevention and control of pollution of water sources for domestic, cultural and household water use, and drinking water with toxic types of CB and cyanotoxins.Compliance with ethical standards. The study does not require the submission of a biomedical ethics committee opinion or other documents.Contributions: Sinitsyna O.O. – research concept and design, text writing, editing; Kuz N.V. – research design development, collection and processing of material, text writing; Pushkareva M.V., Turbinsky V.V., Shiryaeva M.A. – handling material. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study was carried out as part of the implementation of the state program “Ensuring the chemical and biological safety of the Russian Federation” for 2021–2024.Received: November 11, 2025 / Accepted: December 2, 2025 / Published: February 10, 2026