The causes and sources of pollution of the natural environment with heavy metals are analyzed in the study. Basic information on indicators of environmental pollution with toxic metals was presented. When assessing the state of the natural environment, the author emphasizes the need to take into account that the intake of heavy metals is caused by both natural sources and anthropogenic impact. The study provides a review of scientific sources devoted to analytical methods for determining the content of heavy metals in biological media. Within the framework of the study, the author substantiated the conclusion that it is necessary to modernize methods for determining the content of heavy metals in biological media, given that it is possible to assess the level of the content and the adverse effects of heavy metals on the human body only with accurate quantitative indicators of the background content of elements in biological media. In addition, characteristics of the microelement composition of the environment for the region under study are subject to mandatory registration. The author emphasizes the need to develop methodological approaches and establish the background regional levels of metal content in biological media.

The purpose of the study. A systematic study of the urgent problem of pollution of the natural water system and the evolution of water protection zones (boundaries), taking into account their dynamism and risks. A systematic approach is important not only because of the complex consideration of problems, but also to ensure the task of making systemic environmental decisions. Methods. The article uses the methods of systems analysis, statistical analysis, modeling, decision-making, optimization, classification (taxonomy) and risk management systems. Results. A system analysis has been carried out, on the basis of which procedures (algorithms) for modeling the system, algorithmic evaluation of the effectiveness of monitoring of water protection zones, dynamic water systems have been developed. The identification of the linear form from the nonlinear basic functions of the contribution of each pollution factor is used, taking into account the weight coefficients. An approach to the classification of water protection zones according to “tension” (taxonomic analysis) is also proposed. Conclusion. The performed system analysis takes into account the behavior of key (control) factors. This is necessary for the study of all subsystems - organizational and legal, socio-economic, environmental, technological, methodological support (education, consulting, training), etc. The results of the analysis and algorithms will make it possible to evaluate the parameters of water protection works, to solve various practical problems (for example, identification of the contribution to total pollution of each pollutant).