Introduction: Consideration of the problems of prevention, diagnosis and treatment of patients is associated with the study of the subjective opinion of medical workers and the assessment of their role in the development of population health care.

The objective of the study was to study the opinion of medical workers of the Sverdlovsk Region on the availability and quality of care for patients with diseases of the circulatory system.

Methods: In February – March 2020, we conducted a questionnaire-based survey of 303 randomly chosen health professionals, mainly general practitioners and cardiologists, working in urban and rural health care facilities of the region.

Results and discussion: The majority of the respondents believed that the patient’s adherence to prescribed treatment and rejection of bad habits contributed the most to mortality reduction. Standards of medical care and Russian clinical guidelines were reported as the most significant factors in making decisions on patient management. The respondents rated their own competence level quite low in determining the need for medical interventions. When assessing the quality of the follow-up care, the respondents reported regular monitoring of only four parameters (electrocardiogram, platelet and lipoprotein levels, and body weight), explaining the incompleteness of the process by limited opportunities for a proper examination in medical facilities. The health care providers noted the observance of sequencing (routing) in provision of medical care and the possibility of obtaining the necessary medicines; yet, almost half of the respondents specified that the recommended clinical examinations at the outpatient stage of treatment were conducted only in part. When assessing the effectiveness of work of healthcare centers for patients with chronic heart failure, positive changes were noted by 25 % of the respondents while 20 % reported a reduction in waiting time for high-tech care.

Conclusion: The study of the opinion of medical workers helps reveal contradictions in rendering health services. Possessing a well-formed professional mindset, they reflect official (insider’s) views on the problems of the healthcare system in their assessments, but being involved in communication with patients, they express philistine opinions.

Introduction: Among the population of the regions of Kazakhstan, deaths from COVID-19 were more frequent in the regions with high incidence rates. One of these regions was the Atyrau Region, which ranked fifth in the number of the infected in the republic in June 2020.

Objective: To analyze deaths from COVID-19 in the Atyrau Region during the outbreak in 2020.

Materials and methods: We analyzed medical histories of 53 inpatients who died of SARS-CoV-2 infection from June 1 to July 31, 2020 in the Atyrau Region.

Results: The main factors contributing to the lethal outcome included concomitant diseases, such as ischemic heart disease, diabetes mellitus, arterial hypertension, and obesity, which were diagnozed in 37 patients. The mortality rate was higher in elderly cases aged 61–70 years.

Discussion: Arterial hypertension was found to be the most prevalent comorbidity that worsened disease severity in COVID-19. Our study demonstrated that the relationship between hypertension and mortality in patients with the novel coronavirus disease largely reflected their elderly age.

Conclusions: The mortality data in the Atyrau Region showed deaths from COVID-19 during the period of high incidence of the disease in the summer of 2020 (6,069 cases were registered only in July 2020) potentially attributed to comorbidies, elderly age, delays in seeking medical help, a severe course of the disease with > 50 % lung involvement, lack of observation and outpatient treatment at the level of primary health care.

Introduction: Urban population is exposed to a combined effect of physical risk factors. A large number of young people increase their noise exposure by listening to audio files using headphones.

Objective: To study health effects of using headphones in schoolchildren and students.

Materials and methods: In 2019–2020, a questionnaire-based survey of 800 secondary school children and students (345 boys and 455 girls aged 13–20 years) was conducted in the cities of Moscow, Voronezh, and Izhevsk. The inclusion criteria were young age (a pupil/student), a signed informed consent, and no experience (for controls) or a year or more of experience in using headphones with portable electronic devices (for cases). The questionnaire data were analyzed using the statistical analysis software Statistica 10.0 to estimate contingency coefficients and relative risks and to build regression models.

Results: We established that listening to audio files at full volume, using headphones in public transport, and having no headphones-free day a week posed significant health risks for young people: the relative risk of hearing impairment attributed to an every-day use of headphones at maximum volume was 3.20 (95 % confidence interval, 2.40–5.21).

Conclusions: We established risk factors affecting wellbeing and hearing loss in young people. Since these factors manageable, they should be considered in health education of schoolchildren and students.

Introduction: Healthy eating is associated with maintaining and improving health and academic performance of students. Objectives: To assess the adequacy of nutrition of university students on school and non-school days.

Materials and methods: We examined the diet of fifth and sixth-year students of a military university. On school days (Monday to Saturday), all the students had three meals a day at the university canteen, while on Sunday they had meals made in a hostel kitchen or elsewhere. In September to December, we analyzed one typical weekly canteen menu a month (n = 4) and students’ records (n = 50) of actual food consumption on the day off. We proceeded on the assumption that the absorption of mixed food was 85 %.

Results: We estimated that energy expenditures of the students on school days were 3,172.1 ± 33.5 kcal/day, while their physical activity corresponded to labor intensity group 3 with the physical activity coefficient of 1.9. The only non-school day was characterized by the above parameters of physical activity equaling group 2 and 1.6, respectively. Energy expenditures and the energy value of food consumed generally corresponded to the principles of rational nutrition. Yet, the diet was not balanced in terms of percentage contribution of meals (breakfast – 27.7 %, lunch – 46.4 %, dinner – 25.9 %), the intake of proteins and carbohydrates (54.2 % higher and 19.0 % lower than the physiological requirement, respectively), and the ratio of animal to vegetable proteins (44.3 to 55.7 %). Saturated and monounsaturated fatty acids provided 12.6 % and 7.5 % of the calorie intake with the norm of < 10 % and 10.0 %, respectively. We observed increased dietary consumption of vitamins B₁, B₂, PP (13.3 %, 94.4 %, 141.5 % higher than the recommended values) accompanied by a 31.4 % and 20.0 % lower intake of vitamins C and B₆, respectively. The dietary mineral intake was characterized by an excessive consumption of sodium (60.6 %), potassium (43.4 %), phosphorus (138.4 %), copper (90.0 %), and zinc (29.2 %) with a deficiency of calcium, magnesium, and iron (40.4 %, 49.3 %, and 42.0 %, respectively). The calcium to phosphorus ratio was 1:2.8 against the appropriate ratio of 1-2:1. On non-school days, we observed a higher intake of fast digesting carbohydrates and saturated fatty acids and a lower dietary vitamin and mineral intake.

Conclusions: We recommend assessment of student nutrition with account for absorption of nutrients following a preliminary estimation of daily energy expenditures establishing the level of physical activity.

Introduction: The problem of practical application of recommended methods of processing ambient air pollutant concentrations below the limit of detection in chemical analysis raises uncertainties in human health risk assessment. The Federal Clean Air Project has increased legal significance of the latter and the relevance of interdepartmental cooperation in air monitoring activities.

Objective: To review methodological approaches to handling ambient air quality test results and to develop proposals for uncertainty reduction in human health risk assessment.

Materials and methods: We analyzed ways of dealing with values of ambient air pollutant concentrations lying below the limit of quantification of various analytical chemistry methods proposed by the European Bureau for Integrated Pollution Prevention and Control and Russian researchers. A human (population) health risk assessment was conducted based on air quality parameters obtained in 2020 within environmental and public health monitoring in the city of Omsk using averaged concentrations of airborne pollutants measured by different techniques in accordance with national guidelines R 2.1.10.1920–04.

Results: Different approaches to processing air quality test results produced different averaged pollutant concentrations accounting for health risk values ranging from the acceptable level to that of concern. Our estimates showed that certain techniques of quantitative chemical analysis of priority air contaminants are inappropriate for the purposes of human health risk assessment. Photometry, for instance, was found unacceptable for measuring ambient concentrations of formaldehyde to assess carcinogenic risks due to unreasonable overestimation of the latter.

Conclusions: We have proposed criteria for selecting appropriate methods of air quality testing based on estimated values of the lower limit of quantification of chemicals and for optimizing procedures of processing test results for correct assessment of health risks and harmonization of interdepartmental approaches.

Background: People living in the vicinity of large industrial enterprises are known to be exposed to adverse anthropogenic factors. Ambient air pollution is one of the main health risks for the population residing in the areas of oil refining and petrochemical industries. In the study district of the city of Samara, the priority air contaminants, principally emitted by motor vehicles and industrial premises, include sulfur dioxide, sulfuric acid, nitrogen dioxide, hydrocarbons, hydrogen sulfide, and benzene.

Objective: To assess health risks for the population heavily exposed to airborne chemicals in the city of Samara.

Methods: The study was conducted in 2018–2020 in the Kuybyshevsky district of Samara, Russian Federation. Its first stage included hazard identification, i.e. detection of potentially adverse factors, ranking of priority air pollutants having both carcinogenic and non-carcinogenic effects and subject to subsequent risk characterization, and the analysis of xenobiotic concentrations in 7,568 ambient air samples. The next stage included population health risk assessment, the results of which were summarized to group the levels of carcinogenic and non-carcinogenic risks by pollutants, routes and pathways of exposure, and target organs.

Results: We established that the total carcinogenic risk for the population of the industrial district lay within the second range of reference limits and was mainly attributed to inhalation exposure to hexavalent chromium and benzene. The total non-carcinogenic hazard index in the community was < 3 for the group of priority pollutants consisting of sulfur oxide, nitrogen dioxide, hydrocarbons, and benzene emitted by local oil refineries and petrochemical plants.

Conclusions: We obtained permissible risk values for all ambient air contaminants of the industrial district of Samara taken separately. In view of multiplicity of airborne pollutants, however, it is expedient to consider health risks from their combined exposure.

Background: Introduction: Iron is an essential mineral for humans. Its excessive dietary intake has no adverse health effects but high exposure to inorganic iron can induce oxidative stress. Increased Fe concentrations in tap water in the north of the Tyumen Region are attributed, on the one hand, to natural characteristics of its source and, on the other hand, to iron released by deteriorated water pipes. In the administrative centers of this region, high-quality reagent-free water treatment is carried out but tap water quality is largely influenced by the condition of water supply networks with the wear indicators of 26.3 % and 82.1 %, in the cities of Khanty-Mansiysk and Salekhard, respectively.

Objective: To compare iron contents in tap water in Khanty-Mansiysk and Salekhard against its maximum permissible concentration and to assess health risks from exposure to this mineral in drinking water.

Materials and methods: Fifty tap water samples were taken in each of the two administrative centers of the Tyumen Region (Khanty-Mansiysk, Khanty-Mansi Autonomous District – Yugra, and Salekhard, Yamalo-Nenets Autonomous District) for a spectrophotometric analysis of iron. The results were evaluated according to regulations SanPiN 1.2.3685–21, Hygienic standards and requirements for ensuring safety and/or harmlessness of environmental factors to humans, introduced by Decree No. 3 of the Chief State Sanitary Doctor of the Russian Federation of January 28, 2021. Non-carcinogenic risks were assessed in accordance with Guidelines R 2.1.10.1920–04, Human health risk assessment from environmental chemicals.

Results: Iron levels in tap water were found to be significantly lower in the city of Khanty-Mansiysk compared to Salekhard (p = 0.002) with excessive Fe concentrations established in 10 % and 66 % of the samples taken in those cities, respectively. Accordingly, the Fe-related hazard quotient in Khanty-Mansiysk was almost twice as low (0.73) as in Salekhard (1.52) indicating increased likelihood of a toxicological response to the chemical in the latter.

Conclusions: In order to supply residents with drinking water of optimal quality and reduce potential health risks, it is necessary to replace worn out distribution networks, organize and ensure proper monitoring of water quality, duly implement the Regional Clean Water Project and assess its effectiveness.

Introduction: The use of personal protective equipment during the COVID-19 pandemic has affected the majority of the global population. The use of face masks has been proven to reduce the incidence of COVID-19 by 53 % and to be an effective means of prevention, both separately and in combination with other non-pharmaceutical measures. Wearing of face masks and gloves was mandated in different regions of the Russian Federation depending on the epidemiological situation, and it is still required in certain areas and workplaces at high risk of this severe infectious disease. Our literature review has shown that the prolonged mask and gloves use has adverse health effects including headaches, difficulty breathing, and various skin reactions.

Objective: To analyze chemicals contained in commercially available face masks and protective gloves as one of the stages of hygienic assessment of personal protective equipment and to assess whether the established chemical composition can pose a risk of adverse health outcomes.

Materials and methods: In 2021, four types of commercial face masks and protective gloves were analyzed in an accredited testing laboratory center to establish concentrations of chemicals after modeling their release into the aquatic and air environment.

Results: We established that, in all types of masks, the levels of detected chemicals did not exceed their appropriate permissible values. Formaldehyde was found in cotton and latex coated cotton gloves in concentrations exceeding the permissible ones by 1.48 and 1.16 times, respectively. A 1.17-fold excess of the acceptable limit was also registered for zinc in latex coated cotton gloves.

Conclusions: Increased levels of formaldehyde and zinc were found in cotton and latex coated cotton gloves. Formaldehyde can induce adverse skin reactions. Stricter control over production of respiratory and dermal protective equipment and a comprehensive hygienic assessment of PPE are required.

Introduction: V. cholerae non-O1/non-O139 strains are etiological agents of acute intestinal infections of various severity. Monitoring of antibacterial drug resistance of their environmental isolates circulating in specific areas is of great importance for local disease prediction and prevention as well as for an effective choice of drugs for etiotropic therapy.

Objective: To study antibacterial drug resistance of V. cholerae non-O1/non-O139 strains isolated from surface water samples within the annual monitoring of cholera at the Reference Center of the Rostov-on-Don Anti-Plague Research Institute in 2019–2020.

Materials and methods: We tested 263 and 87 V. cholerae non-O1/non-O139 strains isolated from surface water samples in the years 2019 and 2020, respectively, for susceptibility and/or resistance to antibacterial drugs recommended for emergency cholera prevention and treatment using the method of serial dilutions in Mueller–Hinton agar.

Results and discussion: All the isolates were typical non-toxigenic V. cholerae strains containing hlyA genes and lacking wbe-, wbf-, ctxA, tcpA- ones. When comparing the annual proportions of Vibrio cholerae species resistant to different antibiotics, we observed statistically significant changes in the share of those resistant to ampicillin (from 39.2 % to 98.8 %), cefotaxime (from 1.5 % to 5.7 %), and rifampicin (from 31.2 % to 8.0 %). All the studied vibrios remained susceptible to gentamicin and doxycyicline. The data for 2019–2020 indicate a statistical increase in the proportion of multidrug-resistant strains.

Conclusion: Our findings substantiate the necessity of further monitoring studies to understand the spread of antibacterial drug resistance among V. cholerae non-O1/nonO-139 strains.

Introduction: Supporting health and wellbeing of indigenous small-numbered peoples of the North is one of the priorities of the regional policy in the Khabarovsk Krai. The centuries-long adaptation of the population to local conditions has created a unique system of the traditional use of natural resources and the most efficient forms and types of households. Despite all globalization processes, fishing, hunting and gathering remain essential elements of the lifestyle of northern indigenous peoples. Against the natural background, specific features of their behavior and nutrition create optimal conditions for helminth life cycles and intense transmission of endemic helminth infections.

Objective: To assess effects of the traditional lifestyle of the indigenous population of the Khabarovsk Krai as a factor responsible for the spread of larval helminthiasis and endemic trematode infections.

Materials and methods: In 2010–2020, questionnaire-based surveys were conducted and feces samples were collected from Nanai people in the villages of Dada, Sikachi-Alyan, Sinda, and Naikhin and from Udege people in the villages of Gvasyugi and Arsenyevo during expeditions.

Results: Endemic trematode eggs were detected in stool samples from all the villages. Clonorchis sinensis eggs were detected in the samples from Dada, Sinda, and Sikachi-Alyan, while Nanophyetus salmincola schikhobalowi eggs were found in the dwellers of Arsenyevo and Gvasyugi. Metagonimus spp. eggs were also detected in isolated cases. The results of sero-epidemiological survey indicate a high frequency of contacts with Toxocara roundworms in all areas and with tapeworms of the Echinococcus type in the traditional villages located in forest areas.

Conclusion: Original lifestyle and dietary habits of indigenous peoples in the Khabarovsk Krai pose a high risk of trematode infections (clonorchiasis, nanophietiasis, metagonimiasis) and larval helminthiasis (echinococcosis, toxocarosis). In combination with poor awareness of the population of appropriate preventive measures, this risk contributes to high incidence and prevalence rates of helminthiases in all surveyed national villages.