Substantiating the maximum permissible concentration of cylindrospermopsin in water for drinking and household use to minimize human health risks

Increasing human-induced pollution of water objects, climate change, creation of reservoirs, and a decrease in water flow rates have accelerated saturation of water bodies with biogenic substances, which in turn has caused massive growth and spread of cyanobacteria. Intensification of “blooming” processes in water bodies is observed almost everywhere. In respect to human health hazards, the issue of massive growth of toxic cyanobacteria in surface water bodies used for drinking and recreational purposes is related to the possibility of various cyanotoxins forming in the water. This includes cylindrospermopsin (CYN), which is classified by the World Health Organization as a high-priority environmental pollutant, and this highlights high relevance of studying it. Assessing the experience gained by foreign researchers in studying the content of cyanobacteria in water bodies, it should be noted that there is a fairly wide species diversity of blue-green algae, depending on regional prevalence. In many countries across the globe, the list of substances for drinking water quality control has been expanded to include not only the content of cyanobacteria metabolic products, but also, in some cases, the content of their specific species composition. A number of studies by foreign and Russian researchers have shown the need for timely measures aimed at raising drinking water safety by regulating metabolic products of cyanobacteria. The aim of this study was to substantiate the maximum permissible concentration (MPC) of CYN content in water for household and drinking water use, as well as for recreational needs. The study included analysis of the results obtained by research on the physicochemical properties and toxicity of CYN, as well as a subchronic experiment to investigate general toxic effects and specific ones including neurotoxic, embryotoxic, and teratogenic effects upon conditions intragastric administration to animals. As a result, we established parameters of toxic effects produced by CYN and its hazard category and substantiated the MPC for the chemical in water equal to 1.0 µg/l, the sanitary-toxicological indicator of harm, and the hazard category.