T e article presents a methodology for assessing the risk of radioactive contamination of the environment according to the data of radiation monitoring. T e methodology is based on the indicators of radiation exposure and control levels of radionuclides in environmental components, the non-exceeding of which ensures the safety of natural environment. T e risk assessment methodology uses three indicators: an environmental risk index, based on radiation dose rates to reference biota; an integral indicator of pollution of the territory; a generalized risk indicator, estimated in scores, considering both the area and time dynamics of pollution. Examples of methodology application are given, presenting risk assessment for Chernobyl contaminated territories, also risk assessment for radiation hazardous facilities. T e proposed risk assessment procedure can be used to analyzing and interpreting information about radiation risks on the territory of the Russian Federation based on radiation monitoring data, taking into account the requirements of environmental protection, assessment of the state and changes in the radiation situation under the inf uence of natural and anthropogenic factors, including radiation facilities. T e methodology produces reliable integral information about radiation impact on the environment and its interpretation based on the concept of environmental risk. T e results of the risk assessment from radioactive pollution of the environment are used in the development and decision-making on the need for environmental protection measures, and also make it possible to rank the factors of radiation exposure and rationally organize monitoring of the radiation situation.

Using the analysis of the life cycle of fertilizers, it is shown that the values of greenhouse gas emissions can be considered as an indicator of energy ef iiency. Taking into account the huge array of data accumulated in recent years on greenhouse gas emissions (primarily CO2 and methane), it is possible to consider the problem of energy ef iiency (carbon dioxide emissions occur during fuel combustion, f rst of all, as well methane and CO 2 as precursors for N fertilizer) in the chain from fertilizer production to their logistics, application, production and waste disposal. Relevant examples are given in the text of the article. It is shown, that an increase in energy ef iiency in the considered life cycle of fertilizers, from production to utilization of agricultural waste, can signif cantly reduce the role of agricultural production in undesirable GHG emissions. It should be emphasized that reducing the potential of GHG emissions in the production of fertilizers depends on the source of energy used and the transfer of power plants from coal to gas, and especially RES, will be the most signif cant. When growing products, factors related to the use of modern farming systems based on accurate fertilization, the use of electronic soil maps, precision farming and increasing the ef iiency of fertilizer use, in particular, nitrogen and phosphorus, play a very important role.

T is article presents the characteristics of hazardous chemicals that can be found in public and residential premises, considers possible sources of release of hazardous chemicals into the indoor air environment, considers carbon dioxide as an additional factor in the deterioration of indoor air quality.

Since the f rst outbreak in China and the spread of COVID-19 in dif erent countries of the world, the study of mathematical models of the spread of the epidemic has begun and is intensively continuing. Such models are dynamic and of en based on dif erential or dif erence equations. As a rule, these models require an identif cation procedure to determine unknown parameters. But for a number of reasons, unambiguous identif cation of such parameters cannot be performed. For example, the preparation of statistical data for the identif cation procedure may be performed in various ways. T erefore, the preferred method of data preprocessing is to approximate them with the most appropriate functional dependence.

T e study shows that epidemic curves may be represented by a superposition of several local waves — an outbreak of an epidemic in a particular region consists of many local waves and some of them may merge into one common wave. In this article, it is proposed to use analogs of the normal distribution density function to predict waves of new COVID-19 cases. T e purpose of the article was to develop a model of the dynamics of the total number of cases and new cases of COVID-19, taking into account the waves of the epidemic and the impact on the regional socioeconomic system.

T e study was conducted on the basis of data on the incidence of COVID-19 in the Kirov region4 in 2020—2022. It is shown that the chosen model describes statistical data well and allows making  realistic forecasts for the total number of diseases and new cases of diseases. T e results of the study may be used to develop preventive measures to prevent the spread of the disease and allow assessing the impact of the epidemiological situation on the socio-economic system of the region.

In a typical system for ensuring the safety of operation of equipment of complex technical systems, the most important element is the assessment of the individual risk of death (injury) and/or harm to the health of service personnel.. T erefore, in the process of developing a qualitative decision on the formation of a list and parameters of safety program measures, it is necessary to assess individual risk indicators, which is complicated by the presence of various uncertainties that cause the appearance of individual risk during the operation of equipment. T e article presents a simulation model that allows assessing the indicators of individual risk of death (injury) of service personnel during the operation of equipment in order to form a safety program. T is simulation model dif ers from the existing ones in that, as a result of aggregation of models of subprocesses of the operation of a hazardous production facility, it is possible to establish a relationship between the scenarios of the implementation of negative events, the parameters of the safety program measures and the complex ef ects of all signif cant undesirable factors. T e developed simulation model makes it possible to increase the adequacy of the assessment of the risk indicator: the individual risk of death (injury) and/or harm to the health of service personnel. T e ef iiency of the methodology will be demonstrated by the example of receiving an electrical injury by maintenance personnel during operation of the power supply system.

The purpose of this article is to analyze the existing indicative systems used to assess financial security in order to identify their inherent shortcomings. To achieve this goal, an assessment of the financial security of two Russian companies was carried out using six systems of indicators developed by various Russian researchers. As a result of comparing the obtained estimates, it was concluded that such estimates are highly correlated due to the use by the authors of the considered approaches of standard financial analysis coefiiients. In conclusion, it was noted that the key drawback of most of the considered systems of financial security indicators is ignoring the industry specifics of the object of assessment.