Vol 101, No 11 (2022)

Introduction. It is necessary to establish peculiarities and regularities of COVID-19 infection; this task requires further research on how to formalize and build spatial-temporal models of the infection spread. This article focuses on determining non-infectious factors that can modify the epidemic process caused by the COVID-19 coronavirus for further substantiation of integrated solutions that are necessary to ensure sanitary-epidemiological welfare of the RF population.

Materials and methods. Our study involved analyzing regularities of regional differentiation in parameters introduced into mathematical models. These models described how the epidemic process developed in RF regions depending on modifying non-infectious factors identified by modelling the dynamics of spread of SARS-CoV-2 delta strain. These modifying factors included anti-epidemic activities; sanitary-epidemiological, sociodemographic, and economic conditions in a region; weather and climate; public healthcare systems and people’s lifestyles in RF regions over 2020–2021. The dynamics of the epidemic process was modelled by using the conventional SIR-model. Relationships between parameters introduced into the model of the epidemic process and modifying regional conditions were examined by using correlation-regression analysis.

Results. The modelling made it possible to identify priority risk factors that modified COVID-19 spread authentically (p<0.05) and explained regional differences in intensity of contagion, recovery and lethality. We established that population coverage with vaccination, especially among people aged 31–40 years, had the greatest authentic positive influence on the decline of reproduction index (R₀) of the virus (r=–0.37). An increase in monthly average temperatures in autumn and winter as well as over a year made for people moving faster from the susceptible to infected category (r=0.21–0.22). Growing sun insolation over a year, especially in summer, resulted in slower movement of susceptible people into the infected category (r=–0.02–(–0.23)). Next, several sanitary-epidemiological indicators authentically made the infection spread faster; they were improper working conditions (not conforming to the safety standards as per physical indicators) and ambient air quality in settlement not corresponding to the hygienic standards as per chemical indicators and noise (r=0.29–0.24). Recovery took longer in regions where alcohol consumption was comparatively higher (r=–0.32).

Limitations. The limitations of the study include modelling the epidemic process using the standard SIR model; limited set of indicators and period of analysis.

Conclusions. The existing regional differentiation in development of specific stages in the epidemic process related to the COVID-19 delta strain occurs due to complex interactions and influence exerted by modifying factors that create a certain multi-level and multi-component system. This system is able to transform the epidemic process either potentiating it or slowing it down.

Compliance with ethical standards. No approval by the committee on biomedical ethics was required to accomplish this study (it was based on free available data taken from the official statistical reports).

Contribution:
Zaitseva N.V., PopovaA.Yu. — concept and design of the study, writing text, editing;
Kleyn S.V. — concept and design of the study, collection and processing of the material, writing text, editing;
Kiryanov D.A. — concept and design of the study, collection and processing of the material, writing text;
Chigvintsev V.M., Glukhikh M.V. — collection and processing of the material, writing 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: October 20, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. Quality of the environment produces direct effects on public health in large industrial centers. Implementation of air protection activities at heat-and-power engineering enterprises and autonomous heat supply sources (AHSS), including those stipulated within the “Clean Air” Federal project will allow improving ambient air quality on priority territories.

Our research goal was to develop and test methodical approaches to hygienic assessment of air protection activities implemented at heat-and-power engineering enterprises and AHSS with their effectiveness estimated as per health risks.

Materials and methods. We estimated effectiveness of air protection activities implemented at heat-and-power engineering enterprises and AHSS included in the Complex plans. It was done by analyzing changes in spatially differentiated rates of inhalation health risks together with residual risk assessment and estimating a number of people who were removed from zones with elevated exposure levels.

Results. In Krasnoyarsk, we established a list that included 55 priority chemicals out of 251 substances emitted by heat-and-power engineering enterprises and AHSS. At present, these priority chemicals create unacceptable carcinogenic and non-carcinogenic health risks regarding the respiratory system, eyesight, the immune system and some others (CR is up to 3.31•10^–4, HIac is up to 202.31, and HIcr is up to 33.5). Activities to be implemented by 2024 at heat-and-power engineering enterprises and AHSS on the analyzed territory will make it possible to reduce non-carcinogenic risks by 2.57–13.5 times; carcinogenic risks are expected to decrease only slightly. In addition, more than 50 thousand people exposed to high acute non-carcinogenic risks and more than 30 thousand people exposed to high chronic non-carcinogenic risks will be moved to a zone with minimal (target) non-carcinogenic health risks.

Limitations of the study were incomplete data on pollution sources and components of industrial emissions; some uncertainties associated with establishing reference exposure level, critical organs/systems and adverse effects; calculated data on concentrations used for certain chemicals.

Conclusions. Implementation of air protection activities within the existing Complex plan will allow reducing locally occurring public health risks created by heat-and-power engineering enterprises and AHSS. Additional activities are required to mitigate public health risks down to their acceptable levels in the whole city.

Compliance with ethical standards. This study did not require permission by the committee on biomedical ethics (the study was accomplished with use of the publicly available official statistic data).

Contribution:
Andrishunas A.М. — design of the study, collection and processing of material, writing text;
Kleyn S.V. — concept and design of the study, writing text, editin;
Goryaev D.V. — concept and design of the study, editin;
Balashov S.Yu. — collection and processing of material, writing text;
Zagorodnov S.Yu. — collection and processing of material, writing 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: September 6, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. Urban wastewater sludge (UWS) is an important by-product of traditional urban wastewater treatment. Incineration is considered the most effective and universal method of reducing the volume of a large amount of UWS and their disinfection. However, the situation in the areas where the USW incineration plants are located, as a result of the pyrolytic process products entering the atmospheric air, creates complete uncertainty and unpredictability of the development of events that can lead in certain situations to the formation of an additional risk to public health.

The purpose of the study. Hygienic characteristics of wastewater sludge incineration technology based on indicators of atmospheric air pollution and the magnitude of the risk to the health of the population living in the zone of influence of the implemented technology.

Materials and methods. At the first stage, the analysis of the information presented in the international databases PubMed, Scopus, and PRINCE was carried out. Based on the results of the analysis, a list of chemical compounds was formed to identify the qualitative composition and determine the amount of pollutants in industrial emissions into the atmospheric air during the implementation of wastewater sludge incineration technology. Sanitary and chemical studies of industrial emissions into the atmospheric air were carried out by the chemical analytical center “Arbitration” of the D.I. Mendeleev Institute for Metrology. Modern high-precision analytical methods have been used to identify and quantify priority atmospheric pollutants.

Results. Industrial emissions samples laboratory studies were carried out. Measurement results analysis showed that the indicators of quantitative emissions of harmful (polluting) substances do not exceed the international regulations requirements, most are below the detection limit, and the calculated concentrations do not exceed hygienic standards.

The assessment of carcinogenic health risk are determined as acceptable, the probability of developing diseases additional cases from exposure to all the studied carcinogens throughout life in the population permanently residing in the territory in the area of the enterprise location is assessed as insignificant (less than one case).

Limitations. In this study, there was a limitation associated with the method for determining concentrations of substances detection limit, which, nevertheless, satisfies the purpose of the study. Since a sample of unknown composition was taken, the entire possible substances spectrum in the emissions was evaluated. Substances with a carcinogenic effect were present in the emissions, but only those substances that had a carcinogenic potential factor were included in the carcinogenic risk assessment.

Compliance with ethical standards. The study does not require the conclusion of the Biomedical ethics committee.

Contribution:
Gorbanev S.A. — research concept and design, selection of analytical methods, text writing, editing;
Kopytenkova O.I. — research concept and design, processing of experimental materials, analysis of measurement results, statistical processing, text writing;
Ganichev P.A. — research concept and design, collection and processing of experimental materials, analysis of measurement results, statistical processing, literature review, text writing;
Markova O.L., Alekseeva I.V., Dzhambulov R.L. — analysis of measurement results, text writing;
Zaritskaya E.V. — choice of analytical methods, analysis of measurement results, text writing;
Eremin G.B. — literature review, collection and processing of experimental materials;
Isaev D.S. — processing of experimental materials, statistical processing, writing text. 

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

Acknowledgement. The study was carried out under a contract with LLC "Institute of Medical and Environmental Problems and Health Risk Assessment – Construction Design" (LLC "IMEPORZ–SP"). 

Received: July 7, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. The article presents the study results of the effect of personal protective equipment (PPE) from biological factors on the functional state of the medical workers’ body and thermoregulatory reactions when working in the “biohazard zone” of the infectious department.

Materials and methods. The study involved twenty five volunteers (doctors and paramedical staff of the infectious diseases department) performing official duties for 5 hours in the “biohazard zone” with an air temperature of 23.9 ± 1.6 °C and a relative humidity of 39.2 ± 11.8%. Measurements were carried out before the work shift start, during and within 30 minutes after leaving the “biohazard zone” in a room with a comfortable climatic conditions. Recorded indicators were skin temperature, heat, and moisture sensations on 11 areas of the body surface, body temperature (measured in the armpit), heart rate. Based on the obtained data, there were calculated the following parameters including body surface area, average skin, and body temperature, the change in the body’s heat content for each hour of work, moisture loss, and energy consumption.

Results. The use of PPE from biological factors leads to a heat and moisture exchange disorder of the human body with the environment, which is expressed in an increase in “shell” and “core” temperature, moisture loss, energy consumption, and, consequently, overheating, the appearance of uncomfortable sensations, as well as working capacity decrease.

Limitations. When studying the thermal state of the body of 25 medical workers, the tension of thermoregulatory mechanisms when using biological PPE was established, depending on the type of work performed, and the severity of the labour process, gender, age, and weight.

Conclusion. The obtained results showed the greatest impact on the thermal state during work duties in a comfortable climatic conditions to be exerted by the design and thermophysical properties of PPE from biological factors made of vapour resistant and airtight fabrics, as well as a long stay in the “biohazard zone” along with a high degree of psychological stress of their occupational activities.

Compliance with ethical standards: the Local ethics committee of the FSBSI «Izmerov Research Institute of Occupational Health» approved this study carried out under the WMA Declaration of Helsinki (record №3 from 10.03.2021).

Patient consent. Each participant of the study (or his/her legal representative) gave informed voluntary written consent to participate in the study and publish personal medical information in an impersonal form in the journal "Gigiena i Sanitariya (Hygiene and Sanitation, Russian journal)".

Contribution:
Bukhtiyarov I.V. — the concept and design of the study;
Geregey A.M. — the concept, organization and design of the study, writing a text, editing;
Krasnova S.V. — the concept, organization and design of the study;
Konyukhov A.V. — the concept and design of the study, collection and processing of material, writing a text;
Sazhina M.V. — collection and processing of material, writing a text;
Malakhova I.S. — collection and processing of material, writing a text, statistical processing;
Burmistrova O.V. — the concept and design of the study, writing a text;
Losik T.K. — writing a text;
Merkulova A.G. — collection and processing of material;
Kalinina S.A. — collection and processing of 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: September 6, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. In previous studies, we have shown that, despite the modernization of technological processes, working conditions in greenhouse vegetable growing continue to be harmful to the 3rd degree (class 3.3) with a proven occupational risk of development of production-related diseases of the circulatory system, musculoskeletal system, and respiratory system. In this regard, it seemed relevant to clarify the closeness of the relationship between work experience in the occupation and age status with the prevalence of primary non-communicable morbidity (PNCM) in female vegetable growers dealing with protected soil and its nosological structure.

Materials and methods. In this paper, we used the results of extended medical examinations of female vegetable growers at the greenhouse facility of JSC “Sovkhoz-Vesna”, conducted in the period from 2013 to 2017. The level and nosological structure of the primary morbidity in workers were analyzed in accordance with the generally accepted methodology.

Results. It was found that two hundred forty eight general somatic diseases were diagnosed in female workers during the period from 2013 to 2017. The level of PNCM for different years of observation was in the range of 181.8 — 231.9% with a tendency to decrease. The first ranks in the structure of the PNCM were arterial hypertension (AH) — 19.4%, dorsalgia — 12.5%, benign mammary dysplasia (BMD) — 8.9%, chronic bronchitis (CB) — 7.7% and obesity — 7.3%. Correlations of the age factor with hypertension, BMD and obesity corresponded to the gradation of moderate positive associations, with dorsalgia were weak positive ones, with BMD of noticeable positive ones. The age factor made the greatest contribution to the formation of PNCM in relation to BMD (25.7%), CB (22.7%) and obesity (15.4%). In the case of occupational experience, weak negative associations occurred with the prevalence of hypertension and BMD, weak positive ones with CB; negligible ones with obesity and only with dorsalgia, moderate positive ones. The probation factor determined only the development of dorsalgia (12.3%); the contribution to the development of other PNCM ranged from 0.2 to 4.4%. The nature of seniority-age associations with nosologies of PNCM coincided with the trends in the distribution of vegetable workers with PNCM in the functions of age categories and occupational experience.

Limitations. The limitation of the study was the use of data obtained during the examination of vegetable workers of only one greenhouse complex in the analysis of the influence of long-term factors on the prevalence of non-communicable diseases.

Conclusion. Thus, the preservation of the service longevity of working women requires the introduction of complementary health-saving technologies based on the reduction of common risk factors for both occupationally determined pathology and socially significant non-communicable diseases, taking into account gender and age characteristics.

Compliance with ethical standards: the study was conducted with the informed consent of the examined in accordance with the ethical principles of medical research set forth in the Helsinki Declaration of the World Medical Association of the last revision of 2008.

Contribution:
Bezrukova G.A. — the concept and design of the study, statistical processing, writing the text;
Migacheva A.G. — collection of material, statistical processing and writing the text;
Novikova T.A. — writing the text and 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: September 6, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. An urgent hygienic problem in regions with intensive industrial development is inadequate air quality, which causes unacceptable risks of developing somatic diseases among the population in their places of permanent residence.

The purpose of the study is to substantiate the associative relationships of indicators of negative effects on the respiratory organs and the blood system with an elevated blood content of copper, nickel and chromium in children.

Materials and methods. A hygienic assessment of the quality of ambient air in residential buildings was carried out, the risk was assessed, chemical-analytical, biochemical, general clinical, immunological and proteomic studies and statistical analysis were performed.

Results. Established associative relationships of increased blood levels of copper, nickel and chromium with a change in the indicators of negative effects. Markers of the formation of chronic inflammation, accompanied by an imbalance of cellular and humoral immunity, are a decrease in the phagocytic index and number, overproduction of copper-specific IgG, total IgG; markers of a possible violation of the cascade of enzymatic reactions of the plasma system of blood coagulation and vascular-platelet hemostasis is a decine in the expression of prothrombin, vitronectin and hemoglobin beta subunit; development of induction of oxidative processes including an increase in MDA in blood plasma.

Limitations. The conducted study does not make it possible to draw unambiguous conclusions about the effect of the studied chemicals on changes in biochemical and hematological parameters,and as well as morbidity rates, since the possibility of the impact of other factors (heredity, gender and age characteristics) not studied in this work is not excluded.

Conclusion. It is expedient to use the obtained results for the implementation of targeted measures to prevent negative consequences on the part of the respiratory system, the immune system, and the blood system, etiopathogenetically associated with the aerogenic combined effect of nickel, chromium and copper oxides.

Compliance with ethical standards. Compliance with ethical standards. The study was approved by the local ethics committee of the Federal Scientific Center for Medical and Preventive Technologies for Population Health Risk Management of Rospotrebnadzor (protocol No. 1 dated February 6, 2021), and was conducted in accordance with generally accepted scientific principles of the Helsinki Declaration of the World Medical Association (2013).

Contribution:
Zemlyanova M.A. — the concept and design of the study, editing, responsibility for the integrity of all parts of the article;
Zaitseva N.V. — concept and design of the study, approval of the final version of the article;
Ustinova O.Yu. — study concept and design, editing;
Koldibekova Yu.V. — concept and design of the study, statistical processing of the material, writing the text;
Kobjakova O.A. — collection and processing of material, writing the text.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interests. The authors declare no conflicts of interest.

Acknowledgment. The work was carried out in accordance with the State Assignment (State Assignment no. 141-03-2021-029/3 dated September 22, 2021) of the Russian Federation as part of the implementation of the program «Ensuring the chemical and biological safety of the Russian Federation” for the period 2021–2024.»

Received: September 6, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. Contamination of drinking water sources with N-nitrosamines, substances of the first class of danger, creates conditions for the development of disorders of the immune profile in primary school-age children with diseases of the digestive system. Bio- and toxicokinetic features of these substances, when they enter the body with water, form changes on the part of the immune system, and the biodegradation of these substances by enzymes of the first phase of detoxification of the CYP450 family is accompanied by the formation of direct carcinogens capable of DNA methylation, which is characterized by dyspepsia, uncontrolled cell proliferation in the conditions of the CC genotype of the gene of the detoxification enzyme CYP1A1_3 rs4646421.

Materials and methods. The study involved fifty two children of primary school age (6-12 years old) living in the Perm Territory, consuming water from underground sources characterized by pollution with N-nitrosamines. The observation group included 30 children with pathology of the digestive system. The comparison group consisted of 22 conditionally healthy children. Chemical (NDMA, NDEA), immunological (IgE specific to NDMA, IgM, CD95⁺, IL 10, Bcl, cortisol, CA 72-4), and genetic (gene of the detoxification enzyme CYP1A1_3 rs4646421) studies of the biological environment were performed for all children.

Results. According to the results of the conducted studies, it was found that the observation group relative to the comparison group was characterized by an increased content of N-nitrosamines in the blood up to 3.8 times; altered immune status in the form of an increase in specific sensitization to NDMA by 1.2 times, inhibition of apoptotic activity of CD95⁺ markers by 1.8 times (p<0.05) and Bcl2 by 1.3 times, a decrease in the level of expression of the anti-inflammatory cytokine IL10 by 2.3 times (p<0.05), an increase in the expression of the stress hormone cortisol by 1.3 times (p<0.05) and the cancer marker CA 72-4 by 2.5 times; an increase in the frequency of the wild homozygous CC genotype of the CYP1A1_3 rs4646421 gene by 1.5 times, which acted as a risk factor for dyspepsia in conditions of blood contamination with N-nitrosamines (OR=4.5; CI: 1.16-17.40, p<0.05).

Limitations. The limitation lies in the use of the identified markers for the diagnosis of immune disorders manifested by blood contamination with nitrosamines in a specific area.

Conclusion. The obtained results indicate to an imbalance of the immune profile in conditions of low-level chronic oral intake of N-nitrosamines with a genetic predisposition to the development of toxic effects. So far, the detected violations should be attributed to early signs indicating the formation of dyspepsia in schoolchildren consuming water from underground sources contaminated with N-nitrosamines.

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

Patient consent. Each participant of the study (or his/her legal representative) gave informed voluntary written consent to participate in the study and publish personal medical information in an impersonal form in the journal "Gigiena i Sanitariya (Hygiene and Sanitation, Russian journal)".

Contribution:
Kazakova O.A. — the concept and design of the study, the collection and processing of the material, writing text, editing, approval of the final version of the article, responsibility for the integrity of all parts of the article;
Yaroma A.V. — the collection and processing of the material, writing text;
Dolgikh O.V. — writing text, editing, approval of the final version of the article, responsibility for the integrity of all parts of the article.

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

Acknowledgement. The study had no sponsorship. 

Received: September 6, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

The health is influenced by many factors including physical, psychological, emotional well-being, both social and economic viability of the child family. In addition, one of the key factors affecting the maintenance and promotion of health is a balanced diet. Adequate dieting is necessary for the normal physiological functioning of the child’s body, because due to the rapid growth and development, children are very prone to the deficiency of its various components. This issue is especially relevant for children studying in specialized schools. If the principles of a balanced diet are not observed, many symptoms of diseases, including psychoneurological ones, are aggravated and often cannot be corrected.

According to the results of epidemiological studies conducted in different regions of Russia, significant violations in the nutrition of all school-age children were revealed. These include an irrational ratio of essential nutrients, excessive consumption of fat, added sugar and salt, insufficient content of polyunsaturated fatty acids, vitamins, macro- and microelements, dietary fiber, as well as disturbances in the regimen and management of nutrition. It is important to note that the described violations were found in schoolchildren of general education schools, while studies on the actual nutrition of children in correctional schools were not conducted.

Conclusion. Despite a lot of research in the field of nutrition, there remains a need to study the structure of nutrition and nutritional status in children studying in correctional schools to scientifically substantiate and develop measures for the prevention and correction of alimentary-dependent diseases. The main directions of which should be monitoring the nutritional status of children in the following up their development, optimizing nutrition, taking into account the pathology of the child, the use of fortified foods and the appointment of vitamin-mineral complexes, with the aim of additional intake of necessary substances.

When searching for literature, the databases Web of Science, CyberLeninka were used.

Contribution:
Kuchma V.R. — concept and design, approval of the final version of the article;
Tkachuk E.A. — concept and design, collection of material;
Globenko N.E. — concept and design, collection of material, writing the 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: March 1, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. The Ames test is the one of the most popular methods for mutagenicity evaluation of environmental factors. In some cases, this method is suggested to be the only and sufficient assay for the first stage of the equivalence assessment of pesticide technical grade active ingredients (TGAI) to the original products. A limitation of the Ames test is related to the impossibility of an objective equivalence assessment of some cytotoxic TGAIs, in particular, sulfonylureas, and triazolpyrimidines. Based on the mode of action of the pesticides belongs to these chemical classes, we suggested a modification of the plate incorporation method protocol of the Ames test to the increase of maximal non-cytotoxic concentration up to the 5 mg/plate recommended by regulatory documents.

Materials and methods. The five strains of Salmonella typhimurium ТА98, ТА100, ТА1535, ТА97, ТА102 were used. The modification of the protocol included a supplementation of the top agar with isoleucine (1–5 mM).

Results. The maximum non-cytotoxic concentrations of thifensulfuron-methyl and florasulam using the standard top agar did not exceed 0.05–0.125 mg/plate. The enrichment of the top agar with isoleucine allowed evaluating the mutagenicity of the substances up to the maximal recommended concentration of 5.0 mg/plate. The number of spontaneous revertants was within the historical limits of the laboratory control obtained under standard conditions. Positive controls showed pronounced mutagenic effects in case of all strains with and without metabolic activation (p≤0.05).

Limitations. Mutagenicity was evaluated only for TGAIs, which are acetohydroxyacid synthase inhibitors.

Conclusion. The application of the modified Ames test protocol for mutagenicity assessment of TGAIs from the classes of sulfonylureas and triazolpyrimidines under supplementation of the top agar with isoleucine is a more objective way to evaluate their mutagenicity. The proposed protocol expands the possibilities of revealing dangerous mutagenic impurities that may occur in TGAIs in the small quantities, and after entering the environment can cause the gain in the mutation level in living organisms.

Contribution:
Egorova O.V. — the concept and design of the study, the collection and processing of material, writing the text;
Ilyushina N.A. — statistical processing of the material, 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: June 21, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. Safe and qualitative drinking water is among the most significant conditions for minimizing environmental risks to public health.

Our research goal was to develop and test methodical approaches to complex assessment of activities aimed at improving drinking water quality in centralized water supply systems. Within these approaches, effectiveness of such activities should be estimated as per health risk criteria.

Materials and methods. Fuzzy set theory (fuzzy logic) was selected as relevant methodical grounds for estimating effectiveness of implemented activities. Our research objects were activities performed within regional programs and indicators of drinking water quality. A rate of public health risk was selected as a criterion to estimate effectiveness of an activity.

Results. We developed a set of methodical tools that allowed assessing drinking water quality considering a variety of heterogeneous and instrumentally measurable indicators that were divided into several groups. Overall, we included more than 100 indicators that were grouped as organoleptic, sanitary-microbiological and parasitological, sanitary-chemical and radiological ones. We suggested a weighting factor for each indicator of drinking water quality. This weighting factor correlated with severity of health disorders under exposure to improper values of a specific indicator. Ranges of values for each indicator were scaled as per a degree of its hazard for human health and weighting factors were established for each indicator group. The total risk considered effects produced by all the indicator groups, their share contribution to a negative health outcome also taken into account. We determined a value of the membership function to establish where a specific risk would be found on the scale with risk rates from low to extremely high. Health risks were assessed prior to implementation of activities and after it. We also suggested a scale to measure effectiveness of implemented activities. Those activities that resulted in health risk reduction by less than 20% were estimated as low-effective ones. If a risk went down by 20-60%, activities were estimated as moderate or average-effective; a reduction by more than 60% indicated that implemented activities were effective or even highly effective.

Limitations. The use of the existing information database on adverse effects and reference levels under exposure to environmental factors. Should new relevant data become available, this might result in the necessity to revise risk scales and weighting factors of specific indicators.

Conclusion. We tested the suggested methodical approaches within actual projects implemented currently. The testing revealed their relevance to the existing tasks since these approaches facilitate proper assessment of activities as per a system of heterogeneous qualitative and quantitative indicators.

Compliance with ethical standards. No approval by the committee on biomedical ethics was required to accomplish this study (it was based on free available data taken from the official statistical reports).

Contribution:
Zaitseva N.V. — study concept and design, editing;
Kleyn S.V. — design, text writing, editing;
May I.V. — editing;
Savochkina A.A. — data processing, text writing;
Kiryanov D.A. — statistical data processing, text writing;
Kamaltdinov M.R. — statistical data processing, text writing;
Vekovshinina S.A. — collection of material and data processing.
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: September 6, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. It is now known that insomnia has a high comorbidity with various somatic and neurological diseases. In patients with chronic mercury intoxication, sleep disturbances are significantly more common than in the general population.

The purpose of the study is to identify the most significant diagnostic criteria for insomnia disorders in patients with occupational chronic mercury intoxication.

Materials and methods. The study involved thirty patients with occupational chronic mercury intoxication (CMI), who worked at Usolekhimprom LLC, whose mean age was 56±0.71 years, and 30 patients in the comparison group, whose mean age was 54±0.66 years, who complained of disorders sleep without contact with toxic production factors. A neurophysiological (polysnography), psychological (anxiety and depression level) study was carried out, as well as a quantitative determination of some neurotransmitters in the blood.

Results. Polygraphic registration of biopotentials in CMI patients revealed an increase in the time to fall asleep (35.0 (30.5–47.0) min; a decrease in the duration of sleep (total sleep time, 339.5 (305.0–374.0) min); increase in the number of activations (2.9 (1.9–3.6)% of RVO) and total wakefulness during sleep (18.7 (11.3–23.5)%); decrease in the number of sleep cycles (3.0 (2.0–4.0)); decreased sleep efficiency index (70.95 (60.7–78.2)%) and integrative sleep quality index — IISQ (17.8 (13.4–27.5)), in the control group, an increase in total wakefulness within sleep (12.2 (8.4–18.6)%); an increase in the latent period of the REM stage (93.0 (72.0–117.0) min); decrease in the number of sleep cycles (3.0 (3.0–4.0)); decrease in the sleep efficiency index (78.4 (73.9–81.5)%) and the integrative sleep quality index — IISQ ( 14.1 (10.9–20.6)). dopamine levels in the blood, compared with the control group.

Limitations of the obtained results. The results cannot be generalized to workers as the group included only men.

Conclusion. A certain set of diagnostic criteria can be used for the differential diagnosis of insomnia in occupational CMI.

Compliance with ethical standards. In accordance with the principles of the Declaration of Helsinki of the World Association “Ethical principles for conducting scientific medical research involving humans” (as amended in 2008), “Rules of clinical practice in the Russian Federation” (approved by the Order of the Ministry of Health of the Russian Federation of 19.06.2003 No. 266) studies were conducted with the informed consent of the subjects, approved in the prescribed manner by the Committee on Biomedical Ethics. The research did not infringe on the rights, did not endanger the well-being of the subjects, did not harm their health.

Patient consent. Each participant of the study (or his/her legal representative) gave informed voluntary written consent to participate in the study and publish personal medical information in an impersonal form in the journal "Gigiena i Sanitariya (Hygiene and Sanitation, Russian journal)".

Contribution:
Korchuganova E.N. — the concept and design of the study, the collection of material and data processing, writing the text, responsibility for the integrity of all parts of the article;
Katamanova E.V. — concept and design of the study, statistical processing, text writing, design and editing of the article;
Kudaeva I.V. — collection and processing of data, design and editing of the article;
Slivnitsyna N.V. — the concept and design of the study, data collection and processing, writing texts, design and editing of the article.
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. 

Acknowledgment. This work was carried out within the framework of state assignment.

Received: August 30, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

Introduction. At present it is especially vital to search for and test new analytical systems that can give a possibility to predict a medical and demographic situational lowing for multifactorial influence exerted by the environment.

Our research goal was to establish regional peculiarities and predictive estimates of potential gain in such an important indicator as life expectancy at birth (LEB) depending on changes in socio-hygienic determinants potent of modifying it. To do that, we took data collected in a RF region where the current demographic situation was rather tense against the backdrop of stable economic conditions.

Materials and methods. A potential of the gain in LEB was estimated by modelling cause-effects relations between environmental indicators and life-style related ones, or determinants that determined population health. Models were created by using artificial neural networks.

Results. Our methodology was proven to be optimal and precise (differences are equal to 0.98%). It can be applied quite successfully to predict a potential gain in LEB at a regional level together with identifying what modifying factors should be considered priority ones. LEB on the analyzed territory (the Perm region) was established to likely grow by 661.6 days by 2024 and reach 73.12 years; by 855.7 days by 2030 and reach 73.65 years if the current trends related to changes in the analyzed determinants persisted and the achievement of target indicators of national projects and regional development programs. In case the relevant targets set within national projects and regional development programs were achieved, this indicator would grow by 661.6 days and reach 73.12 years. The most significant groups of factors that determine LEB on the analyzed territory against the backdrop of stable economic situation include sanitary-epidemiological welfare (working conditions et al.), public healthcare indicators (population provided with sufficient number of doctors), sociodemographic indicators (expenses on social policies), lifestyle factors (the proportion of the population involved in physical culture and sports; consumption of vegetables and fruits; retail sales of alcoholic beverages, etc.). Their contribution to the gain in LEB varies from 51.2 to 228.6 days.

Limitations. Limitations of the study include the model being “stationary” due to its training relying on data collected in 2010–2019; use of a specific set of indicators; failure to consider the influence exerted by the current epidemiological processes (the COVID-19 pandemics).

Conclusion. We analyzed data collected in an RF region with a rather tense demographic situation and established that by 2024 an adjusted target LEB value would be achieved there if the trend in changes in socio-hygienic determinants recovered to its pre-pandemic levels. Achievement of target LEB values by 2030 requires additional project activities that consider specific regional features and focus on managing priority determinants and reducing mortality among working age population.

Compliance with ethical standards. No approval by the committee on biomedical ethics was required to accomplish this study (it was based on free available data taken from the official statistical reports).

Contribution:
Kleyn S.V. — research concept and design, editing, writing the text, approval of the final version of the article, responsibility for the integrity of all parts of the article;
Glukhikh M.V. — statistical data processing, collection and processing material, writing the text.  

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

Acknowledgement. The study had no sponsorship. 

Received: September 13, 2022 / Accepted: October 3, 2022 / Published: November 30, 2022 

30 сентября 2022 г. исполнилось 75 лет Валерию Анатольевичу Кирюшину — доктору медицинских наук, профессору, заслуженному работнику высшей школы Российской Федерации.