Vol 105, No 6 (2026)

Introduction. Investigating formation of specific immune phenotypes associated with cytokine profile features in viral infections upon their additional modification by exposure to chemical factors will provide better insight into pathways of immune dysfunction associated with environmental factors.

Materials and methods. A mixed population of immunocytes was isolated and cultivated for 48 hours, and the cytokine profile was analyzed by enzyme immunoassay. Inducing factors were represented by benzo(a)pyrene and viral vaccine antigens hemagglutinins of influenza viruses type A and B.

Results. The multidirectional effects of benzo(a)pyrene on the production of pro-inflammatory cytokine mediators were established under exposure "in vitro" conditions with activation of TNF-α and MCP-1 expression and inhibition of IL-8 production (p=0.001–0.018). Modification of cytokine expression in the presence of influenza viral antigens led to preferential stimulation of cytokine production (IL-1β, IL-18, IL-8, IFN-γ, TNF-α, MCP-1) (p=0.015–0.045). Simultaneous introduction of benzo(a)pyrene and influenza virus antigens into the cell culture was accompanied by declining expression of mediators IL-1β, IL-8 and IFN-γ (p=0.005–0.047). Thus, influenza virus antigens stimulate production of pro-inflammatory mediators, while experimental benzo(a)pyrene burden adversly modifies biological effects of viral antigens, inhibiting cytokine expression.

Limitations. The limitations of the methodological approach are related to the need to further verify the obtained results and to extrapolate them to the macroorganism level.

Conclusion. The study findings show the high modifying activity of benzo(a)pyrene affecting the pro-inflammatory cytokine profile, canceling the additional expression of IL-1β, IL-8 and IFN-γ mediators induced by influenza antigens and reducing the protective immune potential. The revealed features of the combined effects produced by benzo(a)pyrene and influenza virus antigens, verified in an in vitro experiment, will allow specifying the mechanisms and peculiarities of the impact of chemical and biological factors to solve the problems of prevention of viral diseases under additional threats and risks associated with chemical exposures (exemplified by benzo(a)pyrene).

Compliance with ethical standards. All donors signed voluntary informed consent to participate in the study. The study was carried out in accordance with the Helsinki Declaration of the World Medical Association (revised 2013) and the Convention for the Protection of Human Rights and Dignity of the Human Being with regard to the Application of Biology and Medicine: Convention on Human Rights and Biomedicine (1999), according to the principles of “Good Clinical Practice” (GOST R 52379–2005) and approved by the Local Ethics Committee of the Federal Scientific Center for Medical and Preventive Technologies for Public Health Risk Management (Protocol No. 3 dated March 20, 2024).

Contribution:
Zaitseva N.V. – study concept and design, editing the text;
Starkova K.G. – study concept and design of the, data collection and analysis, writing the text;
Dolgikh O.V. – study concept and design, editing 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.

Funding. The study had no sponsorship.

Received: April 24, 2026 / Accepted: June 18, 2026 / Published: July 31, 2026

Introduction. Ogun State in Nigeria shares boundaries with the Benin Republic. Socio-demographic characteristics of people and environmental health factors within a given area can influence the health outcomes of the residents.

This study examines the effects of socio-demographic and environmental health factors on well-being of residents in border communities of Ogun State, Nigeria.

Materials and methods. The socio-demographic factors which were considered include age, sex, marital status, number of children, location, duration in location, level of education, income level, occupation and religion. While the environmental health factors comprise availability of health facilities, cost of health services, access to clean water and sanitation status. The study used the quantitative method research design, employing structured questionnaires, which were administered to selected households within the border communities. The data was analyzed using SPSS version 20.

Results. Results show that socio-demographic factors such as occupation, income level, level of education, duration in location, location and age of respondents, in addition to availability of health facilities, cost of health services, access to clean water and sanitation status significantly affect the health outcomes of residents in border communities of Ogun State Nigeria.

Limitations. Most of the residents could not understand or speak English language fluently. The researcher went the extra mile to recruit and train research assistants who could understand and speak fluent English language and also understand and speak the local dialects of these border communities before the study could start. The data collection which took place in three different LGAs in Ogun State Nigeria also raised the cost of transportation and the cost of other logistics required to conduct the study.

Conclusion. The study recommends provision of affordable and adequate health services in these border areas, which will help to improve the health outcomes of the respondents.

Compliance with ethical standards. The study complied with ethical standards on investigation on human subjects by obtaining ethical approval from Covenant Health Research Ethics Committee (CHREC), with the HREC Protocol Assigned Number CHREC/420/2023.

Contribution:
Henry Osita Chukwu – conceptualization, methodology, validation, investigation, data curation, formal analysis, writing-original draft preparation, project administration, funding acquisition;
Dominic Azuh – conceptualization, methodology, validation, writing-review and editing, supervision, project administration, funding acquisition;
Muyiwa Oladosun – methodology, validation, writing-review and editing, supervision, project administration.
All co-authors – approval of the final version of the article, responsibility for the integrity of all parts of the article.

Acknowledgement. We thank the Covenant University Centre for Research, Innovation and Discovery (CUCRID) for their publication support.

Conflict of interest. The authors declare that there is no conflict of interest.

Funding. The study received seed grant funding from Covenant University Centre for Research, Innovation and Discovery with grant number CSG/0103/24/01, which helped immensely in conducting this research and we are grateful.

Received: February 14, 2026 / Accepted: March 24, 2026 / Published: July 31, 2026

The high medical and social significance of noise makes it relevant to develop measures for health risk management, including hygienic assessment of exposure, regulation of exposure levels at the workplace, and occupational risk assessment. There has been conducted a comparative analysis of modern approaches adopted in the Russian Federation and those proposed by international and national organizations, including the ILO, regarding hygienic criteria and standards for noise exposure, methods of occupational risk assessment, and hygienic criteria for establishing the relationship between disease and occupation. A high degree of harmonization has been established regarding the criteria used for the occupational noise exposure assessment. The exposure limit value for the 8-hour time-weighted average sound level established in the Russian Federation is among the lowest in the world, which is a factor contributing to the early implementation of hearing conservation programs, as well as engineering and managerial measures, and to the reduction of risks of occupational hearing loss. A priori occupational risk assessment based on noise levels is an important tool for predicting the likelihood of hearing loss, but models must be verified using modern epidemiological data that provide a posteriori probabilities and risk estimates. The criteria for establishing the relationship between disease and occupation adopted in the Russian Federation are more stringent and include the requirement of exceeding the exposure limit value for noise, as well as a longer work tenure of more than 10 years.

Conclusion. Despite differences in regulations, occupational noise assessment is based on common principles. With the emergence of new data, there is a need to revise the list of parameters, considering the temporal structure of noise, exchange rates, action levels, and refining a priori risk assessment models. An effective system for exposure assessment is a key tool for managing occupational risks.

Contribution:
Bukhtiyarov I.V. – the concept and design of the study, writing text;
Fatkhudinova L.M. – the concept and design of the study, collection and processing of material, writing text;
Amiron N.Kh. – the concept and design of the study, 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.

Funding. The study had no sponsorship.

Received: February 19, 2026 / Revised: April 20, 2026 / Accepted: June 18, 2026 / Published: July 31, 2026

Hygiene as a field of knowledge and practice has been known to humanity for more than 2 600 years, with written evidence found in the LXVIII Orphic Hymn. The development of hygiene as a science is closely linked to scientific and technological progress, while the hygiene of children and adolescents is tied to the development of mass education and upbringing in institutions for children and adolescents, as well as the continuous improvement and modernization of educational systems.

Expert analytical and historical research into the formation and development of training programs in child and adolescent hygiene. F.F. Erisman is recognised as the founder of university‑level training in hygiene and school hygiene at the Imperial Moscow University. The systematic development and improvement of training of medical personnel in educational hygiene and the hygiene of children and adolescents began in 1926 with the establishment of the Department of Educational Hygiene, which was renamed the Department of Child and Adolescent Hygiene in 1954. The optimal model for training students in disciplines in hygiene is the ‘Research Institute – Department’ integrated approach, which facilitates the integration of practice‑oriented education, student and faculty research activities, and educational and volunteer work.

Conclusion. The origins of university‑level training of medical personnel in child and adolescent hygiene can be traced back to the Imperial Moscow University, where it was laid by the prominent Russian hygienist F.F. Erisman, along with his students and followers. The evolution of hygiene education and child and adolescent hygiene is associated with the improvements in healthcare and education systems, as well as with the challenges facing medical personnel training. Modernization of hygiene department activities across the country will contribute to the training of highly qualified specialists with the competencies needed to address contemporary challenges.

Compliance with ethical standards. This study does not require the conclusion of a biomedical ethics committee or other documents.

Contribution:
Kuchma V.R. – the concept and design of the study, collection and processing of material, analysis of research data, writing text, editing;
Butenkova V.S., Platonov O.V. – collection and processing of material, writing text;
Virabova A.R., Naryshkina E.V., Chubarovsky V.V., Yamshchikova N.L. – collection and processing of material, analysis of research data, writing text;
Demina N.N. – collection and processing of material;
Laponova E.D., Makarova A.Yu. – collection and processing of material, analysis of research data, writing text, editing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Statement on the use of artificial intelligence tools. No AI tools were used in the preparation of this article.

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

Funding. The study had no sponsorship.

Received: April 23, 2026 / Accepted: June 18, 2026 / Published: July 31, 2026

Introduction. Cronobacter sakazakii (C. sakazakii) is an obligate pathogen in neonates, causing necrotizing enterocolitis, meningitis, and sepsis. The main transmission factor for these infections is powdered infant formula. Along with C. sakazakii, other Enterobacteriaceae spp., some of which are opportunistic pathogens, have been detected in dry foods for infants. Since all these bacteria are capable of exhibiting thermoresistance, surviving a technological stress such as the high-temperature drying process, there is a possibility that they also have other altered properties, in particular, antimicrobial resistance (AMR).

Objective. To evaluate the AMR profile, including resistance to clinically significant antimicrobial drugs, in C. sakazakii and other associated Enterobacteriaceae spp. isolated from dry foods for infants available on the Russian market.

Materials and Methods. A total of one hundred seventy seven samples of dry foods for infants and their production components were analyzed using bacterial culture with two-stage enrichment followed by biochemical identification of the isolates. The phenotypic AMR profile of the isolated Gram-negative and associated isolates was studied using the disk-diffusion method. For C. sakazakii, Klebsiella spp., and Acinetobacter baumannii isolates, minimum inhibitory concentrations (MICs) were additionally determined. DNA extracts from the isolated strains were analyzed by PCR for genes encoding extended-spectrum β-lactamases (tem, shv, ges, kpc, ctx), carbapenemases (ges, kpc, oxa), and metallo-β-lactamases (imp, vim) and the multidrug efflux pump gene adeF.

Results. Among dry foods for infants, 8.5% were contaminated with Cronobacter spp. and 38.4% - with other thermoresistant Enterobacteriaceae. A total of 65 strains were studied – 15 Cronobacter spp. and 49 associated Enterobacteriaceae spp. Phenotypically, all Cronobacter spp., as well as Klebsiella spp. and A. baumannii strains exhibited high levels of AMR to β-lactam antibiotics, including carbapenems as a priority class, and possessed multidrug resistance to 2–13 antibiotics.Analysis of the genetic potential of AMR to β-lactam antibiotics in Cronobacter and other thermoresistant bacteria from dry foods for infants revealed the presence of extended-spectrum β-lactamase (ESBL) genes in the opportunistic pathogens Klebsiella pneumoniae and Acinetobacter baumannii, which are classified as the ESKAPE group.

Limitations. The mechanisms underlying gene potential for resistance that would support the transmissible nature of AMR, have not been investigated.

Conclusion. When monitoring Cronobacter spp. in dry foods for infants, it is advisable to identify accompanying thermoresistant Gram-negative bacteria. If representatives of the ESKAPE group are detected among them, it is important to study their AMR to clinically significant antimicrobial drugs and their virulence factors. The data obtained will be useful for future recommendations on the quality control of ingredients and the effectiveness of production modes for dry foods for infants and cereals against thermoresistant non-spore-forming bacteria to reduce the risk for contamination with pathogens.

Compliance with ethical standards. The study did not require approval from the biomedical ethics committee.

Contributions:
Smotrina Yu.V. – data collection and processing, writing and editing;
Markova Yu.M., Stetsenko V.V., Bykova I.B., Polyanina A.S., – data collection and processing;
Sheveleva S.A., Efimochkina N.R. – conceptualization, study design, 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.

Funding. The study was supported by grant No. 23-16-00163 from the Russian Science Foundation, https://rscf.ru/project/23-16-00163/

Received: December 7, 2025 / Accepted: June 18, 2026 / Published: July 31, 2026

All categories of food products, such as technological equipment, transport containers, consumer packaging, or tableware used in everyday life without exception, come into contact with various materials in contact with food. To ensure the safety of food products, it is necessary to control compliance with the requirements of the EAEU legislation in this area at all stages of production, from obtaining raw materials to obtaining the finished product intended for consumers during production, storage, transportation, processing, and sale. To achieve this, it is necessary to improve the system of food safety control, an integral part of which is ensuring the safety of materials in contact with food, including the creation of a modern technical and methodological framework, as reflected in the Food Security Doctrine of the Russian Federation.

Study and comparative analysis of methodological approaches to investigate materials in contact with food products in the territory of the Eurasian Economic Union (EAEU), the European Union (EU), the United States of America (USA), and the People’s Republic of China (PRC), identification of key and distinctive aspects in the methodology of research on the safety of the use of materials in contact with food products.

The study used scientific literature sources from electronic databases (Elibrary, Pubmed, Web of Science), as well as regulatory legal acts of the Russian Federation, the EAEU, and other countries in the field of control of materials and products in contact with food products.

The analysis showed the lack of a uniform approach to conducting research on materials in contact with food products in all countries to leads inconsistent research results and may complicate the export of these products.

Conclusion. Due to the relevance of the issue of the safety of the use of materials in contact with food, the issue of developing scientifically based approaches to the sanitary and hygienic assessment of materials in contact with food, which will take into account modern trends in the production of this type of product, include the procedure for their assessment international.

Contribution:
Setko A.G. – editing, collection, analysis, processing of materials, systematization and generalization of data from literary sources;
Yuskina O.N. — editing, material collection and data processing of literary sources.
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.

Funding. The study had no sponsorship and was conducted within the framework of the research project entitled “Scientific substantiation of improved hygienic approaches to ensuring the quality and safety of specialized food products and evaluating their effectiveness, developed to reduce the adverse effects on populations exposed to environmental risk factors, including occupational factors,” registry entry No. 720000F.99.1.BN62AB43000; project registration No. 126030218217-1 in the EGISU R&D; PTNI registration No. 1025032700183-2-3.3.5.

Received: February 10, 2026 / Accepted: June 18, 2026 / Published: July 31, 2026

Introduction. Long-term inhalation exposure to lead nanoparticles may increase health risks for workers. The liver is one of their target organs due to its detoxifying function.

The aim of the study is to evaluate hepatotoxic effects of lead oxide nanoparticles following chronic inhalation exposure in an “in vivo” experiment on rats.

Materials and Methods. Female rats were subjected to chronic inhalation exposure to lead oxide nanoparticles at a concentration of 0.2 mg/m³ for 4 hours per day, 5 times a week for 4 months. After cessation of exposure, we evaluated serum biochemical parameters, liver histomorphology and cytogram, nuclear-cytoplasmic ratio and mitochondrial profile of hepatocytes, and apoptotic gene expression.

Results. Increased levels of malondialdehyde, catalase, and C-reactive protein were observed based on blood biochemistry. Inflammatory and degenerative changes in liver tissue were registered. The mitochondrial profile of hepatocytes shifted toward a vesicular swollen morphotype. Elevated expression of the apoptotic bax gene and a trend toward an increasing bax/bcl-2 ratio were detected in rat liver tissue.

Limitations. Laboratory animals used in the experiment belonged to the same species and sex.

Conclusion. Inhalation exposure to PbO NPs at the concentration of 0.2 mg/m³ induced complex hepatotoxic effects in female rats, the key mechanisms of which include oxidative stress, inflammation, and apoptosis.

Compliance with ethical standards. The study was approved by the local Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (protocol No. 4 of June 12, 2022).

Contributions:
Sutunkova M.P., Minigalieva I.A. – study conception and design;
Shabardina L.V., Gertan N.A. – draft manuscript preparation;
Gavrilova K.A., Sakhautdinova R.R. – data collection and processing;
Shelomentsev I.G., Bereza I.A., Shaikhova D.R., Kikot A.M. – data collection and processing, statistical analysis.
All authors are responsible for the integrity of all parts of the manuscript and approval of its final version.

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

Funding. The study had no sponsorship.

Received: February 4, 2026 / Revised: April 24, 2026 / Accepted: June 18, 2026 / Published: July 31, 2026

Introduction. Taking into account the key activities of the federal project «Water of Russia», the preservation of public health is of particular importance.

Aim of the study. To assess the quality and safety of drinking water from underground water supply sources for the health of the population living in rural areas of the southern Baikal region.

Materials and methods. Study used data from the regional information fund for 2015‒2024. An assessment of the quality and safety of drinking water from underground sources in nine districts of the Republic of Buryatia was carried out, taking into account hygienic criteria, integral assessment and risk assessment of priority chemical pollutants. Statistical significance at p <0.05.

Results. During the study period, there was a 2.2-fold increase in the number of samples tested and indicators from 47 to 54 and a 1.4-fold decrease in the specific gravity of samples that did not meet hygienic criteria. At the same time, there are excess hygienic standards for 18 indicators and increased values of hazard coefficients for two substances. In the Tarbagatai, Ivolginsky, and Kabansky districts, the discrepancy between drinking water and hygienic standards remains due to the influence of anthropogenic factors and the hydrogeological conditions of groundwater that contribute to them.

Limitations. Frequency of monitoring, limited knowledge of cumulative effect of chemicals presents in water assessed by water quality index.

Conclusion. According to the drinking water quality index in rural areas of the southern Baikal region, 7 districts with “very clean” water and 2 with “moderately polluted” were distinguished.

Compliance with ethical standards. The study does not require the submission of the conclusion of the Biomedical Ethics Committee.

Contribution:
Bogdanova O.G. ‒ concept and design of the study, collection of material, analysis and interpretation of data, writing text, editing;
Maraktaev Z.V. ‒ organization of the study, collecting material, statistical data processing, writing the primary version of the text;
Efimova N.V. ‒ study design, analysis and interpretation of data, editing;
Pankov V.A. ‒ analysis and interpretation of data, 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.

Funding. The study was performed within the framework of the state assignment of East-Siberian Institute of Medical and Ecological Research

Received: May 31, 2026 / Accepted: June 18,  2026 / Published: July 31, 2026

Introduction. Tetrachloroethylene (perchloroethylene) is a hazardous chlorinated organic compound posing a serious threat for human health. This chemical referred to the hazard category II is considered a potential carcinogen (class 2A according to the International Agency on Cancer Research classification). Tetrachloroethylene (perchloroethylene, C₂Cl₄) is a chlorinated organic solvent commonly used in various industries due to its properties.

The aim of this study was to develop high-sensitive and selective method to quantify tetrachloroethylene in drinking water by using equilibrium vapor phase gas chromatography (equilibrium vapor phase GC) to provide control and monitoring for hygienic safety.

Materials and methods. The study focused on investigating chromatographic conditions for quantification of tetrachloroethylene and concomitant chlorinated organic compounds (chloroform, tetrachloromethane, 1,2-dichloroethane) in drinking water. The research stages included preparing the water sample for chemical analysis; investigating the extraction degree by the ‘introduced – found’ method; selecting an optimal column and temperature mode for achieving effective division; quantifying the toxicant. To raise quantification precision, we used Chromatek-Krystal gas chromatographer, specific Electron Capture Detector (ECD), and an automated device for water sample introduction (DAZH-2М 3D) to conduct analysis by equilibrium vapor phase gas chromatography (equilibrium vapor phase GC).

Results. We substantiated the optimal conditions for maximum tetrachloroethylene extraction (100%) from water samples by using vapor phase analysis: temperature 80°C, time for achieving equilibrium over 30 minutes with adding 5 g of sodium sulfate. The tetrachloroethylene concentration range, within which the calibration graph was confirmed to be linear, was 0.0001–0.03 mg/dm³.

Limitations. No limitations can be outlined for this study.

Conclusion. The method for tetrachloroethylene (C₂Cl₄) quantification in drinking water by equilibrium vapor phase gas chromatography (equilibrium vapor phase GC), using gas chromatographic division on a capillary column and detection by the Electron Capture Detector (ECD) provides the limit of detection equal to 0.0001 mg/dm³ with the method inaccuracy equal to 39%, reproducibility 8.40% and intralaboratory precision 19%.

Compliance with ethical standards. The study does not require the provision of a biomedical ethics comm other documents.

Contributions:
Nurislamovaа Т.V. — study concept, scientific advice, relevance and conclusions;
Popova N.А. — materials and methods, results;
Maltseva О.А. — relevance, results, discussion and conclusions.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Using AI. GeminiGemini AI-based program. AI helped to structure the text and search for sources referenced in the text of the article. The AI usage date is May 4-5, 2026, the version of the program that is used in the Googl, Gemini, and NotebookLM search engines.

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

Funding. The study had no sponsorship.

Received: March 26, 2026 / Revised: May 6, 2026 / Accepted: June 18,2026 / Published: July 31, 2026