Vol 101, No 6 (2022)

Introduction. The fulfillment of effective measures to manage the level of dust pollution in the atmospheric air of settlements requires correct hygienic assessments of the situation and reliable data on the sources of particulate emissions.

The purpose of the study was to substantiate what is need to take into account the entire set of solid emitted components when conducting hygienic assessments of the situation, including the consideration and approval of draft standards for permissible emissions and projects of sanitary protection zones.

Materials and methods. On the example of a large industrial enterprise, calculations of the dust emissions dispersion were made with and without taking into account the total mass of solid components. Source parameters are taken according to the enterprise inventory list. Dispersion calculations were carried out using the standardized program “Ecolog-City”.

Results. For each individual solid substance at the border of the sanitary protection zone and at the points of the nearest housing no violations of hygienic standards were established to be recorded. The situation was characterized as normative, not requiring measures to improve the safety of the population. The total release of the solid component of emissions (TSP) created an excess of the hygienic standard for the group “suspended substances” (0.5 mg/m³) at the border of the sanitary protection zone. The zone of excess pollution (more than 1 MPC) extended to the residential area. The level of pollution calculated from the totality of solid substances was satisfactorily corresponded with the data of instrumental measurements.

Limitations. The limitation of the study is related to the fact that the obtained results characterize a particular enterprise, however, the principal approaches used can be applied to any similar studies.

Conclusion. It seems appropriate to harmonize the concept of “suspended matter” with the definition adopted by the World Health Organization, establishing that suspended matter is the total amount of solid particles of organic and inorganic substances. Fixing such a concept in sanitary rules and regulations ensures the correctness of the hygienic assessment of the situation, the comparability of calculated and natural data, the absence of contradictions between the established emission standards for each type of dust and the results of a health risk assessment (performed taking into account the sum of all particulate matter). The use of MPCs for various types of dust remains an important tool for identifying emission sources and preventing the negative impact of dusts with carcinogenic or highly toxic properties.

Contribution:
Mai I.V. — the concept and design of the study, the collection and processing of material, writing the text, responsibility for the integrity of all parts of the article;
Zagorodnov S.Yu. — collection and processing of material, mapping of research results, writing a text.
All authors — approval of the final version of the article.

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

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

This article contains the review of methodological approaches to assessment of the perception by the population odours from industrial and other sources, and studying the relationship between the perception of odours with the both the health status and quality of resident’s life, the degree of odour annoyance, using questionnaires. The literature search was carried out using Pubmed, Scopus, Web of Science, MedLine, Global Health, RSCI databases. The long-term practice of surveys of the population living in areas, where sources of emissions of odourous substances are located, has shown annoyance with odours to be a complex reaction, including emotional, behavioral, and somatic aspects. In addition to the direct impact of the odour, it is important to take into account contextual and personal factors that can weaken or strengthen the annoyance. Personal factors include the socio-demographic characteristics of the respondents, “environmental worry”, ways of responding to the situation and the subjective assessment of their own health. Contextual factors include the socio-economic conditions of the population and other indicators of the environmental state. These factors form the blocks included in the model of the relationship between odour impact, odour perception and odour annoyance, which is the basis of a standard questionnaire for a population survey. The questionnaire consists of basic and additional questions combined in several modules. The questions of the main module, which are obligatory and asked in all cases, devoted to the living conditions of the respondents, environmental factors (for example, noise and odours) that, in their opinion, can cause annoyance, have a negative impact on health. The questions of the additional modules (“Health”, “Behavioral changes”, “Environmental worry”) are asked depending on the context and specific objectives of the study. Using this methodology, numerous studies have been conducted abroad, which have shown the presence of correlations between the annoyance of odours, the occurrence of stress and the appearance of symptoms of various diseases. In different countries, the proportion of residents who are “significantly annoyed” by odours, is a criterion for authorities and enterprises to make certain management decisions to reduce emissions. The use of questionnaires can be implemented in the Russian Federation, where enterprises being sources of odours are located, in particular, if there is a problem with odours in the atmospheric air, while complying with the current sanitary legislation.

Contribution:
Goshin M.E. — the concept and design of the study, collection and processing of material, writing the text;
Budarina O.V. — the concept and design of the study, collection and processing of material, writing the text, editing.
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.

Acknowledgement. The research was carried out within the framework of state assignment No. АААА-А20-120101690059-2.

Received: June 1, 2021 / Accepted: June 6, 2022 / Published: June 26, 2022

Introduction. Nanoparticles of molybdenum (VI) oxide (MoO₃ NPs) are used in the production of nanooptics, products of the electrochemical, textile and chemical industries. Currently, the possibility of their application in the fields of oil refining and nanoelectronics is also being considered. Expanding the range of application of MoO₃ NPs can lead to air pollution, exposure of the population and the development of negative effects due to the toxic properties of this nanomaterial. In this regard, there is a need to study the toxicity of MoO₃ NPs under the inhalation.

Materials and methods. The size, surface area, and total pore volume of MoO₃ NPs were determined. A study included assessing of bioaccumulation and pathomorphological changes in tissues of rats organs after a single inhalation exposure to MoO₃ NPs compared with a microsized chemical analogue.

Results. The NPs size was 662.5 nm, which is 5.15 times less than microparticles (MP) (3410 nm). The surface area of the nanomaterial is 3.66 m²/g, which is 1.17 times more than MPs (3.14 m²/g); the total volume of pores located on the surface of NPs was 0.0133 cm³/g, which exceeds this parameter in NPs by 1.18 times (0.0113 cm³/g). An increase in the concentration of molybdenum in the heart, lungs, liver, kidneys and brain of rats 14 days after single inhalation exposure to MoO₃ NPs and MPs was not found. Pathological changes in the tissues of lungs, brain and liver of exposed rats were established. A more pronounced toxic effect of NPs in comparison with MPs was shown in acute plethora and the development of reactive follicles in the lungs.

Limitations. The study was performed only with a single inhalation administration of NPs and MPs of MoO₃ in Wistar rats. 

Conclusion. The tested material is a product of the nanoindustry. It does not possess of bioaccumulation after single inhalation exposure. It causes more pronounced pathomorphological changes in the lung tissues in comparison with the micromaterial. The obtained results should be taken into account when developing preventive measures for workers and the public exposed to MoO₃ NPs and improving the methodology for hygienic regulation of new chemicals.

Compliance with ethical standards. The study was performed in accordance with the European Convention for the Protection of Vertebrate Animals used for Experimental or other Scientific Purposes (ETS No. 123) and the requirements of the Ethics Committee of the Federal Scientific Center for Medical and Preventive Health Risk Management Technologies (Protocol No. 1, dated January 15, 2021).

Contribution:
Zaitseva N.V. — the concept and design of the study, statistical processing of the material, editing;
Zemlyanova M.A. — the concept and design of the study, processing of the material, writing the text;
Stepankov M.S. — collection of material, writing the text;
Ignatova A.M., Nikolaeva A.E. — processing of the 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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Introduction. Workers in the production of chemical fibers in the course of their work are exposed to a complex of harmful factors of working conditions that have a negative impact on their health, but their determining impact on the quality of life has not yet been sufficiently studied.

Material and methods. A one-stage (cross-sectional) study of the subjective assessment of the quality of life of one hundred thirty five workers in the production of polyacrylonitrile fiber was carried out using a non-specific questionnaire for assessing the health status SF-36.

Results. Workers in the production of polyacrylonitrile fibers were shown to highly rated their physical condition. In contrast to their psychological state, the value of the average total indicator of “mental health component” was 48.42±0.54 points, which was statistically significantly lower than the value (54.78±0.36 points) of the total indicator of the physical component (p > 0.05 according to W-Wilcoxon criterion), and corresponded to the average assessment. Men rated quality of life (QOL) more highly on the “physical functioning” scale, women — on the “mental health” scale (p = 0.027 according to the Mann–Whitney U-test). A statistically significant correlation was established between the objective criteria of the level of health (the index of functional changes and the level of physical condition) and an assessment of QOL on the scales of “vital activity” and “mental health”. This indicated to a decline in the QOL in workers against the background of an decrease in the body’s adaptive reserves with increasing age and work experience and low social activity.

The limitations of the study are determined by the area of study of production factors that determine health disorders and QOL in workers in the production of polyacrylonitrile fibers, and psychosocial attitudes of the respondents.

Conclusion. Workers in the production of polyacrylonitrile fibers over the age of 60 and workers with work experience of 21 years or more are high-risk groups and need adequate and timely measures to restore functional reserves, maintain health and psychologically correct the quality of life.

Compliance with ethical standards. Research was conducted in compliance with the requirements of confidentiality of personal data, ethical standards and principles for conducting medical research involving humans, set out in the Declaration of Helsinki of the World Medical Association of the latest (2008) revision. Respondents gave written consent to participate in the study.

Contribution:
Novikova T.A. — the concept and design of the study, writing a text, editing;
Migacheva A.G. — the design of the study, collection and processing of material, writing a text.
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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Due to the problem of population aging, a long working life is becoming increasingly important in modern society. Maintaining the working capacity of employees is one of the effective ways to solve the problems of workforce sustainability associated with the aging of the population. To quantify the potential possibility of continuing to work in the specialty, a group of researchers developed the Work Ability Index (WAI). A literary search was conducted for the queries “Work Ability Index”, WAI in PubMed, eLibrary and other open databases to the full depth since the appearance of the term. WAI was assumed to be based on two interrelated factors: one refers to “subjective ability to work and resources”, the other can be considered as a “health-related factor”. The advantage of the method is to combine several different factors, which should increase its predictive value. There is a correlation between the work-related stress subscales and the average WAI score. In addition to age, the duration of work experience, activity in sports, sleep quality, smoking, employment status and relationship with management and family, body mass index, and the presence of pain syndrome were important.

Conclusion. The method of assessing the ability to work using the work ability index is multi-component, related to taking into account objective and subjective factors. It seems that for research it is advisable to use not only the final value of the indicator, but also the individual items that make up it, as well as the relationship of the index with the phenomena of professional burnout and self-selection. Further determination of the value of the index of working capacity in various production groups, taking into account hygienic, medical and social factors, can help prolong working life, including over old age.

Contribution:
Trubetskov A.D. — concept and design of the study, collection of material and data processing, writing of the text;
Kameneva A.D. — collection of material and data processing, editing.
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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Introduction. Pathologies of the musculoskeletal system have been occupying the leading place in morbidity among schoolchildren for a long time.

Our research aim was to examine peculiarities of developing postural disorders in schoolchildren from different age groups.

Materials and methods. We examined seventy two primary schoolchildren (their average age was 8.19±0.32 years); 87 middle schoolchildren (12.94±0.24 years); and 54 senior schoolchildren (16.65±0.21 years). These test groups were comparable for gender and social background. The health of the musculoskeletal system was assessed on the base on data of a medical examination and results by laboratory tests (phosphor-calcium metabolism); postural disorders were examined as per surfaces with a computer optical topographer; bone mineral density was determined by ultrasound osteodensitometry; body composition was assessed with bioimpedance analysis (BIA).

Results. Pathologies of the musculoskeletal system were detected in 77–83.3% schoolchildren. Each second child in primary and middle school had deforming dorsopathy and each second senior school student had scoliosis. We established a probability of developing scoliosis to be by 5.9 times higher in senior school. Children in primary school predominantly had twisting postural disorders (28.4%) and swayback (11.1%) accompanied with the lower phase angle, a lower share of active muscle mass detected with BIA and osteopenia developing in ¼ cases. 16.1–26.1% of middle schoolchildren had twisting postural disorders and kyphosis, 57.9% children in this age group had lower contents of ionized calcium in blood, 28% had osteopenia and a decrease in fat-free mass detected with BIA. Scoliosis in senior schoolchildren (51.9%) and kyphotic-lordotic back (24.1%) were accompanied with lower contents of phosphor and alkaline phosphatase, developing apparent osteopenia (18.4%) and lower mineral mass. We established the probability of postural disorders developing in three surfaces to be 3.3 times higher among teenagers in senior school.

Limitations. The results of the studies can only be extrapolated to the population of 7–17 years children of both genders.

Conclusion. We revealed certain peculiarities of developing postural disorders in schoolchildren. They can be used in implementing health-preserving technologies in schools as well as in developing new hygienic and organizational approaches to the conditions of the educational process in schools.

Compliance with ethical standards. The screening study was conducted after obtaining written voluntary informed consent from the legal representatives of children and in accordance with the ethical principles of the Declaration of Helsinki (as amended in 2008), the National Standard of the Russian Federation GOST R 52379-2005 “Good Clinical Practice” (ICH E6 GCP), approved by Ethics Committee of the Federal Scientific Center for Medical and Preventive Health Risk Management Technologies (protocol No. 2, 2016).

Contribution:
Maklakova O.A. — the concept and design of the study, writing the text, editing, approval of the final version of the article;
Vandysheva A.Yu. — collection and processing of material, writing the text;
Shtina I.E. — collection and processing of material, editing;
Valina S.L. — editing.
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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Introduction. The issue of sanitary safety of the population under the conditions of chronic exposure to environmental anthropogenic chemical factors, which play an etiological and pathogenetic role in the formation of non-communicable diseases, especially in the occurrence of bronchial asthma (BA) in children, is currently becoming particularly relevant.

Materials and methods. Sixty six institutions located near major highways were examined. Of these, the observation group consisted of 21 children whose content of manganese, chromium and formaldehyde in biological media significantly exceeded background values (p < 0.05). The comparison group consisted of 45 children with the content of haptens in biological media at the level of background indicators. The analysis of biological media for the content of chemical allergens by mass spectrometry, formaldehyde was made with high-performance liquid chromatography (HPLC). The study of the immune status of the examined cases included the use of flow cytometry (CD3, CD4, CD25, CD95), enzyme immunoassay (leukotrienes, IL1ß, IL4, IL6, IL8, IL10, INFu, TNFa, IgE total), the Mancini method (radial immunodiffusion) (IgM, IgG, IgA) and allergosorbent testing (specific to allergen metals and formaldehyde IgE).

Results. A comparative analysis of the immune and allergological status of the subjects revealed children with atopic bronchial asthma, characterized by excessive contamination with bio-mediated haptens, to show a significant increase in total and formaldehyde- and chromium-specific IgE, leukotrienes, as well as lymphocytes expressing CD25 and CD95 molecules (p < 0.05) and a decrease in cytokine expression.

Limitations. There were no restrictions on the conduct of research related to reagents and instrumentation.

Conclusion. As a result of the performed studies, there were substantiated immunological markers of the effect, reflecting the modification of the immunological response of children with asthma in conditions of elevated contamination of the biological media with chromium, manganese and formaldehyde, which have an adjuvant effect on the body, forming the features of immunological manifestations of asthma (for example, the city of Perm).

Compliance with ethical standards. The study was conducted in accordance with the norms of the Helsinki Declaration of the World Medical Association “Ethical principles of medical research involving people as subjects” and the National Standard of the Russian Federation GOST-R 52379-2005 “Good Clinical Practice” (ICH E6 GCP).

Contribution:
Alikina I.N. — the collection and processing of the material, writing a text, editing;
Dolgikh O.V. — the concept and design of the study, writing a text, editing.
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.

Acknowledgement. The study had no sponsorship.

Received: April 25, 2022 / Accepted: June 8, 2022/ Published: June 26, 2022

Introduction. According to the World Health Organization, among young people, the prevalence of behavioral factors determining the violation of their health is especially increased. It determines the relevance of studying the influence of leading socio-hygienic, behavioral risk factors on the quality of life of modern adolescents.

Material and methods. A survey of 15–17-year-old students of schools (n=489) and vocational college (n=292) was conducted. There were determined body mass index (BMI); type of eating behavior — according to the DEBQ questionnaire; quality of life indicators – according to the PedsQL™4.0 questionnaire. A questionnaire was conducted to identify behavioral risk factors. The data is statistically processed. The significance level of the differences was determined by the Student’s criterion for parametric and the Mann–Whitney U-test for nonparametric features. The differences were considered significant at p<0.05–0.001. Odds ratios (OR) were calculated to establish risk factors.

Results. Insufficient level of motor activity was a priority among adolescents. The associations of increased screen time with low physical activity among schoolchildren (OR=1.455) and college students (OR=1.251) were determined. The prevalence of smoking among school and college students was 23.6% and 33.8%, respectively. The components of irrational nutrition were determined; there was a decrease in the frequency of meals as they grew older, eating disorders. 28.5% of schoolchildren had disharmonious physical status. Among college students, body mass disorders were found in 26.2% of cases. The study of quality of life indicators in adolescents showed the highest scores on the scale of social functioning. The indicator of the final assessment of the quality of life was 79 points for schoolchildren, 73 points for college students. The probability of a decrease in the overall quality of life score among schoolchildren most depended on motor activity (OR=1.696) and prolonged use of gadgets (OR =1.550). Insufficient physical activity (OR=1.400) and tobacco smoking (OR=1.615) were statistically significant in the forecast of the probability of a decrease in the overall quality of life score among college students.

Limitations. The study is limited to studying the influence of leading socio-hygienic, behavioral risk factors on the quality of life of schoolchildren and college students.

Conclusion. Further research is needed to identify causal relationships between socio-hygienic, behavioral risk factors and indicators of the quality of life in adolescents, taking into account the active introduction of modern technological forms of education into the education system in schools and vocational colleges.

Compliance with ethical standards. Research was conducted in compliance with the requirements of confidentiality of personal data, ethical standards and principles for conducting medical research involving humans, set out in the Declaration of Helsinki of the World Medical Association of the latest (2008) revision. Written consent to participate in the study was obtained from the respondents.

Contribution:
Spirin V.F. — the concept of research, writing and editing the text;
Milushkina O.Yu. — text editing;
Eliseeva Yu.V. — research concept, material collection and data processing, text writing.
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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Introduction. Aluminum foil is one of the most widely used food packaging, since it has a set of high consumer characteristics. At the same time, the food foil can serve as a source of aluminum entering the human body, but there is no specific method of testing foil. In this regard, the study of the spectrum and features of the application of food simulators is relevant to improve various stages of food aluminum foil testing. 

The purpose of the study is to investigate the features of the use of food simulators and testing stages used as a whole for any food packaging in the study of aluminum foil. 

Materials and methods. With the application of the elements of the PRISMA systematic reporting reports on systematic reviews, the analysis of scientific and technical literature on the features of the use of food simulators when testing the food aluminum foil were performed. Measurement of aluminum content in food simulators after contact with aluminum foil was carried out by spectrometry methods. 

Results. When testing the food aluminum foil, it is impractical to the use of the entire list of food simulators recommended by TR TS 005/2011. It was established to be advisable to improve the current instructive methodological base, in particular the pre-analytic stage of sample preparation. A method of sample preparation and spectral measurement methods was carried out by a comparative experimental measurement of real samples of food simulators after contact with the foil. 

Limitations. The limitation of the study was the use in the experiment exclusively of samples of aluminum foil with a thickness of 0.009 mm from aluminum alloy 8011 and aluminum foil with a thickness of 0.02 mm from aluminum alloy 1200. account the features of the use of aluminum foil into everyday life, therefore, the methodological approaches to the stages of its testing need to be improved. The developed method of sample preparation allows applying unified requirements in the process of testing food aluminum foil to safely use it in everyday life.

Conclusion. The list of model environments for the study of any food packaging does not take into account the specifics of the use of aluminum foil in everyday life, therefore, methodological approaches to the stages of its testing need to be improved. The developed method for sample preparation allows applying unified requirements in the process of testing food-grade aluminum foil for the purpose of its safe use in everyday life.

Compliance with ethical standards. Research does not require the submission of a biomedical ethics committee opinion or other documents.

Contribution:
Shur P.Z., Ulanova T.S. — concept and design of the study, editing;
Redko S.V., Stenno E.V., Vejhman G.A. — collection and processing of material, statistical processing, writing text.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Acknowledgment. The research work was carried out as part of off-budget cooperation and with the financial support of Open Joint Stock Company JSC «RUSAL SAYANAL».

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

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Introduction. Variable analytical control methodologies are applied in monitoring over contents of low molecular weight organic compounds in ambient air. Their unification is a vital and serious challenge requiring valid substantiation and selection of optimal air sampling techniques.

Our research goal was to substantiate and select an air sampling technique for chemical analysis of furan and methylfuran.

Materials and methods. Our research concentrated on developing and optimizing the process of air samples preparation for chemical analysis of furan and methylfuran; examining effectiveness of furan and methylfuran sorption-desorption using various sorbents. Standard furan and methylfuran samples (≥99.0% Sigma-Aldrich), heptane solvents, sorbent tubes with Tenax, Sylochrom С-120, and coal as sorbents were used in the research. All experimental studies were aimed at testing effective procedures for taking and preparing air samples for further furan and methylfuran analysis in them. They were performed on "Kristall-5000" gas chromatographer with mass-selective detection (MSD) and 25-meter long PoraPlotQ-capillary column.

Results. We comparatively analyzed the results produced by taking air samples for further detection of furan and methylfuran in them using different techniques. They included low temperature concentration; sorption on filters made of quartz microfiber and a sorbent tube with Nenax TA; sorption on a tube with Tenax ТА at t=20–25 °C. The analysis enabled us to reveal an effective procedure for taking ambient air samples for further detection of furan and methylfuran in them. This procedure was low temperature concentration of low molecular weight organic compounds on a sorbent tube with Tenax ТА.

Limitations. The accomplished study had no limitations.

Conclusion. The accomplished study allows us to recommend taking air samples during 10 minutes with consumption being 0.1 l/min for further detection of furan and methylfuran in them using low temperature concentration on a sorbent tube with TenaxТА. The achieved effectiveness is 99.2% for furan and 100% for methylfuran.

Compliance with ethical standards. The study has been accomplished in full conformity with the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS N 123), the Directive of the European Union and the European Council 2010/63/EC dated September 22, 2010  on the protection of animals used for scientific purposes.

Contribution:
Ulanova Т.S. — overall concept, scientific advice;
Nurislamova T.V. — topicality, conclusion;
Maltseva О.А. — materials and methods, results, discussion, conclusion;
Popova N.А. — analytical and experimental work.
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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

Introduction. The development of SARS-COV-2 (COVID-19) pandemic creates certain analytical challenges with respect to both examining the spread of the disease itself and investigating reasons and regularities in the epidemic propagation under different conditions. This article dwells on the least examined issue related to the necessity to establish peculiarities and reasons for occurring differences in the coronavirus infection spread in RF regions with different socioeconomic and social-hygienic status. This is necessary for substantiating relevant actions, which are to compensate for preventable modifying influence exerted by environmental factors and lifestyle-related ones.

Materials and methods. The study involved analyzing regularities in regional differentiation of parameters in a classic SIR model describing the epidemic process in RF regions. We analyzed data on more than two hundred fifty various indicators describing levels of infection, vaccination, hospital admission and mortality among population collected in 85 RF regions in 2020–2021. All the data were taken as average values over a week.

Results. We assessed parameters of mathematical models for RF regions. The assessments gave grounds for analyzing peculiar development of the epidemic process and for detecting basic regularities in the territorial distribution of parameters describing rates of infection, recovery and mortality rate and the basic reproductive number for SARS-COV-2 virus.

Limitations. The results are limited by data aggregation performed only at a regional level and a simplified model of the developing epidemic process applied in the present study. Another limitation is insufficient coverage of environmental factors reflecting peculiarities in the infection spread. The latter is considered a promising trend in future research.

Conclusion. The study made it possible to trace basic peculiarities and regularities in the spread of the disease and to spot out regions where the epidemic process was the most acute and accompanied with the highest burdens on regional social security services. These trends and regularities indicate to the occurring regional differentiation detected at various stages in the development of epidemic process of the new coronavirus infection (COVID-19) spread due to the Delta strain caused by complex interactions and influence exerted by modifying factors creating a certain multi-level and multi-component structure.

Compliance with ethical standards. The study was approved by the local ethical committee of the Federal Scientific Center for Medical and Preventive Health Risk Management Technologies.

Contribution:
Zaitseva N.V. — the study concept and design, writing, editing;
Popova А.Yu. — the study concept and design, writing, editing;
Alekseev V.B. — the study concept and design, writing;
Kiryanov D.А. — the study concept and design, data collection and analysis, writing;
Chigvintsev V.М. — data collection and analysis, writing.
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.

Acknowledgement. The study had no sponsorship.

Received: April 11, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022

The author of the article, on the basis of factual historical material, briefly talks about how the Moscow City Sanitary Organization was born in the years preceding the official date of the creation of the sanitary authorities of the young Soviet republic; about the difficult experience of becoming the founder of the sanitary business in Russian cities; about the huge anti-epidemic and general sanitary activities carried out by sanitary doctors.

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

Acknowledgement. The study had no sponsorship.

Received: January 13, 2022 / Accepted: June 8, 2022 / Published: June 26, 2022