Introduction. For more than 80 years of its operation, JSC Usolekhimprom (Usolye-Sibirskoye, Irkutsk region) has released a significant amount of pollutants into the environment, such as mercury, lead, manganese, nickel, formaldehyde, phenols, etc. Despite the measures taken to rehabilitate the territory affected by the plant's activities, environmental pollution in Usolye-Sibirskoye remains a large-scale environmental problem and poses a threat to the city's population. Earlier it was found that the mortality rate of the population in the city exceeds similar indicators in comparison with the Irkutsk region and Russia in all age groups (child population, working age, older than working age). Scientists have established the maximum excess of the mortality rate among the working-age population.

The study aims to assess the hygienic and socio–economic situation in the territory of Usolye-Sibirskoye and determine its impact on the causes and mortality rates of the working-age population.

Materials and methods. Based on the official yearbooks of Roshydromet and reports of the Ministry of Natural Resources and Ecology of the Irkutsk region, the authors studied the state of the environment in Usolye-Sibirsky for 2010–2019. The scientists analyzed information on the main indicators of socio-economic development according to analytical reports on the socio-economic situation in the municipality "Usolye-Sibirskoye" for 2010–2019, as well as based on information from the database of indicators of municipalities of the Irkutsk region (Irkutskstat).The authors studied the mortality rate of the working-age population according to forms C-51 "Number of deaths by sex, age and individual causes of death" and 2RN "Population by sex and age" for 2010–2019. Based on the data obtained, they calculated age-standardized mortality rates from the main classes of causes in accordance with the indicators averaged over 10 years. As a standard, the researchers adopted the age structure of the Russian population for 2010 in accordance with the census data. Standardization was carried out by the direct method.

Results. There is a severe environmental situation in Usolye-Sibirskoye is experiencing associated with man-made pollution of all components of the biosphere, including carcinogenic substances. When comparing mortality rates in Usolye-Sibirsky with regional and average Russian values, experts revealed an excess of mortality rates from all studied classes of causes among both men and women. There is an extremely unfavorable situation in terms of mortality from infectious diseases (5 times and 7.3 times higher compared to Russia for men and women, respectively), including from HIV infection and tuberculosis, as well as causes of death related to alcohol, the prevalence of which is associated with the socio-economic instability of the city. It is possible to note high mortality rates from causes that have an etiological connection with the consequences of the production activities of the Usolekhimprom enterprise (from diseases of the nervous system, malignant neoplasms, liver diseases).

Conclusion. Sanitary and hygienic living conditions of the population of Usolye-Sibirskoye can be characterized by an extremely high level of contamination of all components of the biosphere with substances of hazard classes 1–2 and carcinogens. The unfavorable socio-economic situation due to the closure of the largest enterprise exacerbates the existing risks of premature mortality and leads to an increase in mortality from socially significant diseases. The working-age population is most vulnerable to these factors, since it is on it that the entire demographic burden falls.

Ethics. The study did not require the conclusion of the Ethics Committee.

Contribution:
Bukhtiyarov I.V. — research concept and design, editing of the article;
Bryleva M.S. — data collection, data analysis and interpretation, writing the article, editing of the article;
Betts K.V. — data analysis and interpretation, writing the article, editing of the article;
Tikhonova G.I. — data analysis and interpretation;
Salagai O.O. — research concept and design.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 02.10.2023 / Accepted: 24.10.2023 / Published: 05.11.2023

Introduction. The emotional burnout of nurses is an urgent problem of the modern healthcare system. Emotional burnout of nurses entails a decrease in their mental and physical health.

The aim of the study was to evaluate the role of professional activity in the development of emotional burnout syndrome in nurses.

Materials and methods. The nurses (109 persons) at the age from 19 to 63 years were the objects of the study. The nurses were divided into 4 probation categories: experience less than 10 years, 10–20 years, 21–30 years and more than 30 years. Physiological, questionnaire, and statistical methods were used.

Results. 77.8±0.62% examined nurses had a manifestation of emotional burnout syndrome (EBS), formed at least in one of the phases. The most significant EBS manifestations were in the form of professional achievements reduction (more than 60% surveyed), emotional exhaustion (from 45.4 to 22.3%) and low values of depersonalization (11.2÷16.8%). According to the Copenhagen Burnout Inventory (CBI), more than 50% participants suffered from moderate burnout in all its subscales. The percentage of nurses with high burnout level was 37.2±0.004% for the work-related subscale, 36.2±0.005% for the personal burnout-related subscale and only 26.4±0.003% for the patient-related subscale. The results of the assessment of the working capacity level according to the WAI questionnaire registered that nurses in the probationary dynamics had a significant decrease from the «good working capacity» level (38.2±0.79 points) in the first probationary group to «unsatisfactory working capacity» level in the third and fourth groups (34.6±1.36 and 29.8±2.09 points, respectively, p<0.05). The adaptation process was accompanied by the regulation mechanisms tension and was characterized by a decrease in the degree of predominance link of the parasympathetic over the sympathetic link of the autonomic nervous system and an increase in the degree of centralization of heart rate control.

Limitations. This study is limited to a sampling of nurses of Karaganda hospitals who acquired emotional burnout syndrome during their industrial activity. Emotional burnout was diagnosed by the questionnaires of Maslach, Jackson and Copenhagen Burnout Inventory.

Conclusion. Nurses are exposed to adverse the complex of production factors during their professional activities. And stress is the most frequent factor. Prolonged exposure to occupational stress is the cause of the emotional burnout development, the increase of which leads to a decrease in efficiency and in high-quality performance of their professional duties. At the same time, compliance with the norms of professional ethics among nurses remains a priority.

Ethics. Since non-invasive research methods were used in the work, submission of the conclusion of the Biomedical Ethics Committee or other documents is not required.

Contribution:
Smagulov N.K. — concept and design of the study, writing text, editing;
Ageev D.V. — collecting and processing material, writing text.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 03.10.2023 / Accepted: 24.10.2023 / Published: 05.11.2023

Introduction. In connection with the development of measuring and computer technology, new opportunities and approaches are opening up to solve the problem of measurement, hygienic assessment, normalization and prediction of hearing impairment from exposure to unstable, in particular, pulse noise.

The study aims to analyze the applicability of a model for assessing hearing loss based on the use of an excessive correction to the exposure of impacting noise, according to the draft ISO 1999:2023 standard.

Materials and methods. The scientists have conducted an expert and analytical comparative analysis of ISO 1999 standards, which define the basis for assessing hearing loss due to noise exposure. The experts have carried out a literary review of domestic and foreign sources on the problem of using the index of the distribution of instantaneous values of sound pressure — excess to assess constant and non-constant noise, as well as its role in the formation of hearing loss under the action of non-Gaussian pulse noise, the applicability of the prediction model of the ISO 1999 standard to various types of noise exposure.

Results. The scientists presented the results of the analysis of: indicators for assessing the adverse effects of non-constant, including pulse noise; the relationship between the effects of non-Gaussian noise and the constant shift in the hearing thresholds of workers; statistical indicator of excess — an indirect indicator of the temporal structure of noise, a significant risk factor in combination with noise exposure in the assessment of hearing loss.

Conclusion. Revision of the ISO 1999:2013 standard with the introduction of a new indicator of the temporal structure of noise — kurtosis, will improve the accuracy of the method of predicting hearing loss when exposed to constant, non-constant noise, including impulsive.

Ethics. In preparing the article, the authors were guided by the ethical principles of medical research set out in the Helsinki Declaration of the World Medical Association of the last revision.

Limitation. Features of ISO 1999 standards dedicated to the assessment of the impact of industrial noise and the assessment of noise-induced hearing impairment.

Contribution:
Prokopenko L.V. — concept and design of the study, analysis of regulatory documents and literary sources, writing and editing the text of the article;
Сourierov N.N. — concept and design of the study, analysis of normative and methodological documentation, calculations and analysis of results, writing the text;
Lagutina A.V. — analysis of normative and methodological documentation, editing.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 25.10.2023 / Accepted: 30.10.2023 / Published: 05.11.2023

Introduction. Maladaptive mental states pose a threat both to the personal health of the employee and to the stability of the organization. Mental health workers often have states of depression, mental and chronic fatigue, occupational stress and emotional burnout. At the same time, burnout is one of the most dangerous conditions, especially at the beginning of its development — the employee, as a rule, is not aware of its symptoms. It is important to identify such manifestations in time and properly organize the employee support system. It is necessary to determine the factors contributing to the development of emotional burnout syndrome in various age and gender professional groups, taking into account individual psychological characteristics.

The study aims to research burnout and its predictors in knowledge workers, taking into account their gender and age characteristics and the class of working conditions according to the intensity of the labor process.

Materials and methods. The authors conducted an online study of maladaptive mental states and working conditions of knowledge workers in terms of the intensity of the labor process, including a set of hygienic and psychological methods. The study involved 468 employees aged 20–59 years: 133 men (42.1±9.7 years) and 335 women (39.3±8.7 years). The researchers conducted a hygienic assessment of labor stress factors according to the Manual R 2.2.2006-05. The authors used: "degree of chronic fatigue", questionnaire for evaluation of acute mental fatigue, labor stress questionnaire; Maslach burnout questionnaire with subsequent calculation of integral index of burnout according to Bekhterev Scientific Research Institute formula; Beck depression scale. The experts compared the studied indicators depending on gender, age group, class of working conditions according to the intensity of the labor process and calculated a linear regression model for the indicator "integral index of emotional burnout".

Results. There are 13 professional groups of knowledge workers with different classes of working conditions depending on the intensity of the labor process, for which there are leading labor stressors. The authors revealed statistically significant differences in the studied indicators depending on gender, age group and class of working conditions in terms of the intensity of the labor process, they also identified significant predictors for the indicator "integral index of emotional burnout": age (β=–0.160, p=0.013), acute mental fatigue (β=0.432, p=0.000), depression (β=0.403, p=0.000), second (β=0.343, p=0.020) and third (β=0.432, p=0.000) in terms of stressors (adjusted R²=0.698).

Conclusion. Ensuring the longevity of knowledge workers should be based on the preservation of their psycho-emotional health, which requires a special approach to the prevention of maladaptive mental states. When developing preventive measures, it is necessary to take into account, first of all, the age characteristics of the employee and the class of working conditions according to the intensity of the labor process, estimated according to the Manual P 2.2.2006-05, as well as the gender of the employee, the level of depression and mental fatigue, leading labor stressors. In order to prevent burnout, it is necessary to focus more on situational and organizational factors than on individual ones.

Ethics. The authors have conducted the study in accordance with the Helsinki Declaration and approved by the Local Ethics Committee of the Izmerov Research Institute of Occupational Health, Protocol No. 4 of 04/14/2021.

Contribution:
Merkulova A.G. — concept and design of research, material processing, writing and editing of text;
Kalinina S.A. — material processing, text writing, editing;
Zakrevskaya A.A. — material processing, text writing, editing;
Dmitrieva E.V. — material processing, text writing, editing;
Forverts A.Yu. — collecting and processing material, writing text.
All co–authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 29.08.2023 / Accepted: 07.09.2023 / Published: 05.11.2023

Preserving the health of workers when using shift forms of work for oil and gas extraction in harsh northern climatic regions is an important task and requires a special approach to ensuring medical control of this category of persons and the scientific development of preventive measures aimed at maintaining the normal functional state of the body, maintaining well-being, efficiency and health of workers. In the most frequently cited sources of scientific literature there are results of numerous studies of working conditions, the labor process, life support and morbidity of gas-oil workers of shift forms of work during the development of hydrocarbon deposits in the North. However, many practical issues related to the scientific development and application of preventive measures aimed at preserving the health of shift workers have not yet been resolved.

Based on the analysis of numerous works by domestic and foreign authors, regulatory documents devoted to the problem of the influence of cold, climatogeographic, production and life-supporting factors on the body of shift workers in the northern regions of the country, researchers have identified the main and current directions for improving the health of oil and gas complex workers in the shift form of labor organization.

Shift work in the North has its own characteristics: workers from other regions of the country and neighboring states (Belarus, Kazakhstan, Armenia, Azerbaijan, etc.) experience additional loads associated with cold and adverse effects of climatic and geographical conditions, adaptation takes place with a significant restructuring of metabolic processes in the body.

Significant changes occur in the systems: respiratory, hematopoietic and cardiovascular, endocrine, reproductive (in men and women) and nervous, as well as in the immune system, up to their possible imbalance, which causes a reduction in the reserve capabilities of the body, which can be both functional and pathological. Improving the health of workers when using shift forms of work in oil and gas production in harsh northern climatic regions is one of the important tasks and requires a special approach to ensuring medical control over this category of persons and solving many practical issues to improve life support and working conditions.

Contribution:
Losik T.K. — the concept of the article, collecting material, writing text, editing;
Shuporin E.S. — writing the text, approval of the final version.
All co-authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 12.07.2023 / Accepted for printing: 14.09.2023 / Published: 05.11.2023

The article presents in detail the history of the creation of hygienic normative documents regulating the industrial and non-industrial effects of electromagnetic fields in the Russian Federation. Systematic scientific research in the field of biological action and hygienic regulation of radio frequency electromagnetic fields in our country began at the Research Institute of Occupational Hygiene and Occupational Diseases, Academy of Medical Sciences of the USSR, where in 1952 specialists created the first laboratory of electromagnetic waves of radio frequencies in the country. In the future, a number of scientific institutions of hygienic, biomedical and physico-technical profile joined these studies. Scientists have scientifically substantiated the methodology of rationing hygienic factors. Over the past period, scientists have developed about 30 documents, including the maximum permissible level of electromagnetic fields. Currently, in the Russian Federation, the main current document establishing the maximum permissible level of permanent and variable electromagnetic fields in the workplace and for the public is SanPiN 1.2.3685-21 "Hygienic standards and requirements for ensuring the safety and(or) harmlessness of environmental factors for humans". The analysis made it possible to evaluate its advantages and identify disadvantages, as well as to outline promising areas of scientific research to improve existing and develop new maximum permissible levels of electromagnetic fields created by modern sources.

Ethics. This study did not require the conclusion of the Ethics Committee.

Contribution:
Pokhodzey L.V. — concept and design of research, data collection and processing, text writing, editing;
Palkov Yu.P. — concept and design of research, data collection and processing, text writing, editing;
Fedin I.A. — data collection and processing.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 06.09.2023 / Accepted: 15.09.2023 / Published: 05.11.2023

The study of various pathological conditions associated with COVID-19 remains an urgent task. The most important manifestation of COVID-19 is the defeat of the cardiovascular system, one of the possible variants of which may be the development of myocarditis.

Medical workers are at an increased risk of infection with the SARS-CoV-2 virus. A new coronavirus infection in medical workers can be considered an occupational disease if the infection occurred while they were performing their professional duties.

The study aims to describe two clinical observations of myocarditis associated with a new coronavirus infection in medical workers, with the establishment of its causal relationship with professional activity.

The article presents a description of a moderate variant of the course of covid-associated myocarditis in medical workers with cardiac arrhythmia in the form of ventricular extrasystole, the development of chronic heart failure. There is a need for a multidisciplinary approach to the diagnosis and treatment of COVID-19 manifestations with the mandatory participation of a cardiologist, advanced training in the field of COVID-19 communication, taking into account complications and peculiarities of working conditions of medical workers.

Ethics. The study was conducted in compliance with Ethical principles and with the voluntary informed consent of the participants.

Contribution:
Strizhakov L.A. — concept and design of the study, editing;
Babanov S.A. — concept and design of the study, the text writing;
Gulyaev S.V. — concept and design of the study, the text writing, editing;
Azovskova T.A. — concept and design of the study, data collection and processing, the text writing;
Konovalov D.V. — data collection and processing, the text writing;
Lavrentieva N.E. — data collection and processing, the text writing, editing;
Baraeva R.A. — data collection and processing, editing.

Funding. The study had no funding.

Conflict of interests. The authors declare no conflict of interests.

Received: 22.05.2023 / Accepted: 07.09.2023 / Published: 05.11.2023