Introduction. Based on an expert assessment of the impact of hospital environmental factors on patient recovery and staff health, as well as taking into account the results of a comprehensive hygienic assessment of the main physical, chemical, and biological factors affecting humans in inpatient medical facilities (IMFs), a list of priority indicators for the quality and safety of the hospital environment for premises for various functional purposes has been substantiated.

Material and methods. To assess the impact of hospital environmental factors on patient recovery and staff health, a 23-member expert group was formed, including hospital hygiene specialists, physicians, architects, and designers. A comprehensive hygienic assessment of bacterial, viral, and fungal contamination of the air and various surfaces, as well as chemical contamination and physical factors, was conducted in the main functional areas of the maternity hospital, treatment buildings of the municipal clinical hospital, and the research institute.

Results. The main indicators of the quality and safety of the indoor environment of the Inpatient medical institutions premises, in terms of their impact on the processes of patient health restoration, were established to be: at the first place there is the contamination of the air with bacteria, viruses, and fungi; at the second place there are the temperature and humidity parameters in the premises; the third place is occupied by the presence of chemical pollutants in the air; and at the fourth place there is the ionizing radiation; followed by noise conditions and artificial lighting of the premises. Moreover, in operating rooms, dressing rooms, procedure rooms and operating units, in addition to bacterial and viral contamination, artificial and natural lighting are of primary importance: in treatment rooms – microclimatic parameters, noise level, gas composition of the air; in treatment, diagnostic and laboratory rooms – EMF intensity, noise levels; in physiotherapy rooms – air temperature and relative humidity, EMF, noise levels, fungal contamination of the air; in auxiliary rooms (food blocks, buffets, halls, corridors) – noise load.

Limitations. The results of this study do not apply to the premises of field mobile hospitals.

Conclusion. Hospital environmental factors were ranked based on their impact on patient recovery and the occurrence and spread of Health-care associated infections (HAIs). A list of priority indicators for the quality and safety of the hospital environment was identified, taking into account the functional purpose of the premises.

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

Contributions:
Zhernov Yu.V. – concept and design of the study, editing;
Kalinina N.V. – concept and design of the study; data collection and processing, text writing;
Zagainova A.V. – data collection and processing, statistical processing.
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 conflict of interest.

Funding. The work was carried out within the framework of the state assignment with the code "Risk indicator 25–27", registration number EGISU 125032604484-5.

Received: August 18, 2025 / Revised: November 11, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. The problem of biofilms in drinking water supply systems is well-studied; however, their presence in bottled water requires additional attention.

The aim of the study was to assess the microbiological composition and potential risk of transparent suspensions (sediment) found in bottled natural mineral table non-carbonated drinking water.

Materials and methods. A comprehensive sanitary-microbiological study of the water was conducted. The standard analysis for compliance with the requirements of TR EAEU 044/2017 included the determination of standardized indicators (TVC, Coliform bacteria, E. coli, P. aeruginosa, enterococci) according to GOST 34786–2021. For the analysis of suspensions, there were used methods of concentrating large volumes of water (1 and 3 dm³) by centrifugation and membrane filtration followed by inoculation onto nutrient media (Nutrient Agar, Endo Agar, Sabouraud Agar, Brolacin agar, MRS agar) by the direct method and via thioglycolate enrichment broth. Species identification of all grown colonies was performed using time-of-flight mass spectrometry (MALDI-TOF MS). Additional studies for coliphages and parasitological objects were also conducted.

Results. A standard analysis of two hundred fifty cm³ of water did not detect E. coli, coliform bacteria (BGKP), or other regulated pathogens. An excess of the standard for total microbial count (TMC) at 22 °C by a factor of 2 (289 CFU/cm³) was recorded; however, according to TR EAEU 044/2017, this test was not required in this case. After concentrating 1 and 3 dm³ of water, diverse microorganisms were identified in the suspended solids, including Escherichia coli, Kocuria rhizophila, Micrococcus luteus, Aquabacterium parvum, Microbacterium testaceum, as well as the fungi Aspergillus fumigatus and Syncephalastrum racemosum. Coliphages and parasitic objects were not detected.

Limitations. The study was conducted once on one batch of bottled natural mineral drinking water. It is necessary to conduct a series of similar studies on biofilms of a different composition to confirm the correctness of the developed tactics.

Conclusion. The results demonstrate that standard control methods based on the analysis of small volumes (up to 250 cm³) may be insufficient to detect microbiological contamination present as local aggregates (suspensions or biofilms) in bottled water. The detection of E. coli after concentration indicates fecal contamination and a potential epidemiological risk. The obtained data justify the need to develop and implement extended control protocols, including the concentration of representative water volumes and use of enrichment media, to ensure the safety of packaged drinking water.

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

Contribution:
Alekseeva A.V. – study concept and design, writing the text, collecting material and processing data, editing, approval of the final version of the article, responsibility for the integrity of all parts of the article;
Zagaynova A.V. – study concept and design, editing;
Rakhmanin Yu.A., Rusakov N.V. – editing, approval of the final version of the article;
Kurbatova I.V., Kravchenko K.S. – collecting material and processing data.

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

Funding. The study had no sponsorship.

Received: June 6, 2025 / Revised: November 27, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Obnoxious odors in ambient air in industrial centers are a significant medical and social issue.

The aim of this study is to develop and test methodical approaches to identifying potential obnoxious odor sources in residential areas of regions with developed industries using fuzzy logic and systematic hybrid data analysis.

Materials and methods. We have developed and tested a complex eight-stage methodology for identifying priority obnoxious odor sources in the urban environment. The suggested approaches have been tested using actual data collected in a large industrial center. Fuzzy logic is used as a method for identifying areas where odor sources are likely to be located. Within the method, an odor is given as a linguistic variable that considers people’s complaints and meteorological conditions. We have analyzed one thousand nine hundred twenty seven people’s complaints about obnoxious odors and meteorological parameters (2022–2024), ambient air monitoring data (automated pollution control stations, readings taken at representative points (GC-MS)) and have accomplished computational simulation of 23 olfactory-active substances together with calculating source contributions, sensor estimates, GIS-modeling, and graphic spatial analysis.

Results. Testing of the developed universal algorithms has established 249 chemicals to be olfactory active out of total 375 ones emitted into ambient air. We have found a spatial-temporal correlation between complaints, meteorological conditions and time: 67% complaints are made when the wind speed is 0–1 m/sec; the peaks are reached in the evening (59.3%) and morning (22.4%). Chemical levels systematically higher than single maximum MPC have been confirmed by field observations: hydrogen sulfide (up to 17.5 MPC), formaldehyde (up to 3.2 MPC), and ammonia (up to 1.5 MPC). We have identified three zones where obnoxious odor sources are likely to be located in the analyzed area (15.85–31.8 km²); these zones correspond to industrial clusters. Ranking of 21 enterprises as potential pollutant sources has established 6 priority ones creating >80% of the total contribution to concentrations of odor chemicals in places where people’s complaints are usually made.

Limitations. The results are based on routine operation of obnoxious odor sources; emergency situations have not been analyzed.

Conclusion. The developed universal approach to identifying obnoxious odor pollution sources under uncertainty has been found to be effective in variable meteorological conditions and to be ready for testing in other areas with similar problems.

Compliance with ethical standards. The study does not require approval by an ethical committee or any other documents.

Contributions:
Zaitseva N.V. – study concept and design;
Patyashina М.А., Prokofyeva М.V. – data collection, editing the text;
Kleyn S.V. – study concept and design, data collection, writing the text;
May I.V., Kiryanov D.А. – study concept and design, editing the text;
Klyachin А.А. – data collection and analysis, writing the text;
Chigvintsev V.М. – data collection and analysis.
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: July 23, 2025 / Revised: November 19, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Objective. A comprehensive analysis of current data on oil pollution of soils as a source of hygienic hazard, including an assessment of the impact on human health and analysis of the regulatory framework in the Russian Federation.

A review of more than forty scientific reports from Google Scholar, CyberLeninka, eLibrary, PubMed, and Scopus databases was conducted. The methodology included an assessment of the sources and extent of pollution, an analysis of the component composition and behavior of pollutants in soil, and a critique of the regulatory framework (SanPiN 1.2.3685–21, SanPiN 2.1.3684–21).

Oil pollution was shown to lead to the degradation of soil ecosystems and poses a multicomponent hazard to the health of occupational groups and the population living in oil-producing regions. The current sanitary regulations was found to fail to contain Maximum Allowable Concentrations (MACs) for oil and petroleum products in soil, which is a serious limitation for effective sanitary control. The existing methods for the total determination of petroleum hydrocarbons in soil are often non-selective and lack proper metrological certification for hygienic research.

Conclusion. Addressing the hygienic problem of oil pollution of soils requires consolidated efforts in the following areas: development and approval of differentiated MACs for oil and main petroleum products in soil; improvement and metrological certification of analytical control methods; implementation of scientifically based remediation technologies considering regional specifics. A comprehensive approach is a prerequisite for ensuring environmental safety and preserving public health.

Contributions:
Ibragimova S.Sh. – research concept and design, data collection and processing, text writing, editing;
Ushakova O.V. – research concept and design, text writing, editing;
Evseeva I.S. – data collection and processing, text writing, editing;
Vodianova M.A. – research concept, 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.

Received: October 1, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Carbohydrates, including dietary sugars and prebiotic oligo- and polysaccharides, can influence on the functional activity of probiotic bacteria by modulating their metabolic processes. An important property of prebiotics is the selective activation of endogenous protective populations of intestinal microflora, which helps to suppress the growth of pathogenic and opportunistic microorganisms. However, the specificity of various prebiotic supplements for specific exogenous probiotic microorganisms remains unclear. Probiotics can be components of a wide range of foods and dietary supplements, so it is important to understand how various nutritional substrates influence on their metabolic and functional activity. This knowledge will enable the development of more effective products and supplements aimed at maintaining intestinal bacterial balance. ”In vitro” studies allow evaluating the effects of individual components on probiotic strains. In this work, the effect of various carbohydrate substrates on the antagonistic activity of exogenous probiotic strains Lactobacillus paracasei and Bifidobacterium longum against a number of opportunistic microorganisms was studied.

Objective — to study the effect of various carbohydrate substrates, including well-known prebiotics, on the antagonistic activity of probiotic strains studied against opportunistic pathogens. The choice of a carbohydrate that improves the competitive properties of probiotic strains of L. paracasei and B. longum.

Materials and methods. The antagonistic activity of two probiotic strains against seven pathogenic microorganisms was studied in the presence of nine different carbohydrate substrates using a two-stage cultivation method in a combined system.

Results. Probiotic strains were established to exhibit selective antagonistic properties against the same pathogen, depending on the presence of a particular carbohydrate source. For example, lactose and sucrose were found to contribute to an increase in the degree of antagonistic activity of lactobacilli against Staphylococcus aureus from moderate to high relative to the control and other substrates, and inulin and FOS suppress the competitive properties of this strain relative to Pseudomonas aeruginosa. The studied strain of Bifidobacterium longum exhibits moderate antagonistic activity against E. coli and C. jejuni, however, a number of substrates (sucrose, mannitol, inulin, chitosan) are capable of inhibiting this property. At the same time, substrates such as lactose, maltose, sucrose, chitosan, and N-acetyl-D-glucosamine increase antagonistic activity from low to moderate against K.pneumoniae, P.aeruginosa, and A.baumannii. Based on the data obtained, it can be assumed that N-acetyl-D-glucosamine (NAG), mannitol, maltose, and lactose are of interest as substrates that increase the antagonistic potential of the studied strains against a number of opportunistic pathogens.

Limitations. Antagonistic activity in co-cultivation of probiotic strains has not been studied. It is also difficult to assess the functional properties of the studied strains depending on the prebiotic in the gastrointestinal tract. In addition, the effect of the concentration of carbohydrate substrates used in the work on the antagonism of target probiotic strains has not been studied.

Conclusion. We have identified a significant effect of the carbohydrate component on the antagonistic properties of the probiotic strains studied, which can be further taken into account in the development of probiotic compositions, synbiotics, and functional foods.

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

Contribution:
Kalashnikova I.G. – concept and design of research, collection of material and data processing, writing text, conducting research;
Nekrasova A.I. – concept and design of research, editing;
Gritsyuk O.V., Fedets Z.E., Pankova M.N. – conducting research, methodology development;
Zagainova A.V. – providing research, project administration;
Zhernov Yu.V., Makarov V.V. – definition of the concept, attraction of financing, provision of research;
Yudin S.M. – attraction of financing, provision of research.
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 work was performed within the framework of the state task No. 388-00154-22-00 “Creation of micellar probiotics of a new generation for targeted changes in the composition of the human microbiota in chronic non-communicable diseases”.

Received: October 2, 2025 / Revised: November 24, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

The gastrointestinal tract (GIT) microbiome is known to significantly impact on human health and be involved in many metabolic processes. The composition of the intestinal microbiota is variable and depends on both endogenous and exogenous factors. Regional climatic and geographical factors influencing the composition of the intestinal microbiota have not been characterized for the population of the Russian Federation (RF). 39% of Russia’s area is in the taiga zone, 13% in the arctic desert, tundra, and forest-tundra zones, 6% in the mixed forest zone, 8% in the forest-steppe and deciduous forest zone, 5% in the steppe zone, 1% in the semi-desert zone, and 2% in the desert zone. Each climate zone is characterized by unique climatic conditions, so when assessing the composition of the intestinal microbiota of Russian residents, it is crucial to pay attention to the regional aspect as one of the key factors influencing on changes in the composition of the human microbiome. In addition to climatic and geographical factors, there are also cultural and socio-economic factors, which is confirmed by the results of many global population studies.

The aim of the study. Systematization of key exogenous factors shaping the gut microbiome: geographic features, urbanization level, climate conditions, and ethnic and national dietary patterns. Experts consider these factors when determining the relative norm for the composition of the human gut microbiota, diagnosing dysbiosis in both indigenous and non-native populations.

Material and Methods. This review is based on scientific studies published over the past ten years and presented in the PubMed, Google Scholar, Scopus, Web of Science, and eLIBRARY.RU databases.

Conclusion. The review reveals the influence of region of residence on the intestinal microbiota parameters of relatively healthy individuals living in various climatic zones and areas with different levels of urbanization, which can be used to determine the normal flora for residents.

Contribution:
Nekrasova A.I. – text editing, collection, analysis, processing of materials, systematization and generalization of literature data;
Kalashnikova I.G. – collection of material and processing of literature data, text editing;
Makarov V.V. – text editing, concept and design of the review and analytical research;
Zhernov Yu.V. – text editing, concept and design of the review and analytical study.
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: October 2, 2025 / Revised: November 18, 2025 / Accepted: November 19, 2025 / Published: January 15, 2026

Introduction. Dynamic olfactometry, with participation of a team of human panelists as sensors, was developed to quantify odor concentrations in samples of atmospheric air and model mixtures.

The aim of the work is to evaluate the informativity of a number of salivary biochemical and immunological parameters as possible markers of human olfactory acuity in model olfactometric study of emissions from food industry enterprises.

Materials and methods. Experimental study is based on the use of ECOMA T08 olfactometer, three food odorants with odors of orange, cognac and coffee, 10 panelists tested with n-butanol, standard methods for assessing cytokines IL-1β, IL-6, IL-8, sIgA, NAG, α-amylase, intensity of luminol-enchanced chemiluminescence in the samples of mixed saliva of the participants

Results. An algorithm has been developed for the preprocessing of olfactometric data, optimal for their correlation analysis with saliva molecular parameters. Among 7 saliva markers under study, there is shown only one to be associated with human olfactory acuity in Spearman’s correlation test – IL-8 content (R= −0.392; p=0.032 with odor thresholds and close to reliable positive associations with perceived odor intensity in combined data matrix, N=30). Peculiarities of the scatterplot «odor thresholds/IL-8» suggest healthy persons with a sharper sense of smell to have more flexible mechanisms for releasing IL-8 in response to provoking changes in oral microbes, and this chemotactic signal, in turn, leads to timely attraction of blood neutrophils, reducing bacterial colonization and thickness of supraepithelial mucus, and so to more efficient binding of odorant molecules with olfactory receptors.

Limitations. Small sample sizes, although they correspond to the practical purposes of the European standard EN 13725.

Conclusion. The data obtained indicate that dynamic olfactometry, created as a practical tool for assessing odor concentrations in atmospheric air, can also be used to study the molecular mechanisms of olfaction.

Compliance with ethical standards. The consent of the Local Ethics Committee of the Centre for Strategic Planning of the Federal medical and biological agency of Russia was obtained for conducting of the research involving human participants (Protocol No. 3 of 08/17/2020). All participants gave informed voluntary written consent to participate in the study.

Contributions:
Khripach L.V. – research concept and design, biochemical and ELISA assays, writing the article;
Knyazeva T.D. – biochemical and ELISA assays;
Andryushin I.B. – olfactometry;
Budarina O.V. – research concept and 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 had no sponsorship.

Received: October 16, 2025 / Revised: November 11, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. One of the approaches to identifying a hazard to public health is the standard scenario method.

The aim – to test approaches to assessing exposure load under conditions of long-term exposure to mercury coming from the environment and industrial environment.

Materials and methods. Standard scenarios for men of three ages (20, 40, and 60 years) were considered; three urban residential zones (up to 3 km, 3–5 km, and more than 5 km from the combined industrial site); and two work options (at enterprises located on and off-site). Data from monitoring mercury concentrations in the atmospheric air of a “model city” and the air of the combined industrial site of an enterprise with a mercury electrolysis shop during various periods of its operation were used. Calculation and assessment of doses and hazard quotients were conducted in accordance with R 2.1.10.3968–23.

Results. During the period of active operation of the enterprise, the average annual concentrations of mercury in the atmospheric air in residential zone I of the “model city” were 0.00054 mg/m³, in zone II – 0.00046 mg/m³, in zone III – 0.000008 mg/m³. During the period of equipment dismantling the average annual values of mercury concentrations in the atmospheric air of the city decreased significantly and reached 0.0000001 mg/m³. In the post-operational period, mercury was not detected in the atmospheric air. The hazard coefficient value corresponds to the alarming level for men working at enterprises on the territory of the combined industrial site, in the following groups: 40 years – with a place of residence in zone I; 60 years – regardless of place of residence.

Limitations. The use of standard exposure conditions in scenarios that do not take into account the individual characteristics of daily exposure and the occupational route, including for male workers in the electrolysis shop, incomplete data on the long-term actual content of the pollutant in the air of the combined industrial site and residential area introduce uncertainties in the assessment of quantitative chronic exposure.

Conclusion. Modeling scenarios of long-term mercury exposure in men not exposed to the toxicant in their workplaces demonstrates the risk posed by mercury emissions from the air of the integrated industrial site during the operation of the enterprise.

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

Contributions:
Mylnikova I.V. – data collection and analysis, scenario calculations, text writing;
Efimova N.V. – study concept and design, scenario development, text writing;
Savchenkov M.F. – study concept and design.
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 carried out within the framework of the Exploratory Scientific Research "Development of technologies for a comprehensive assessment of the health of the population living in areas of accumulated damage from previous economic activity in single-industry towns in Siberia".

Received: June 2, 2025 / Revised: November 27, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. As a result of long-term economic activity of chemical plants in urban agglomeration areas, an increased accumulation of potentially hazardous toxic compounds has been observed.

Materials and methods. Biomonitoring, atomic absorption method, statistical analysis

Results. In vegetable samples collected in the Usolsky district, mercury levels ranged from 0.029 to 0.095 mg/kg (1.45–4.75 MPL), with the highest excess levels observed in carrots (0.091 and 0.093 mg/kg), peppers (0.092 mg/kg), onions (0.094 mg/kg), and cabbage (0.095 mg/kg). In the biological environments of the population of the Usolsky district revealed ecotoxicant levels over the range of 0.0–5.4 and 0.0–3.0 µg/l in urine and blood among adults, respectively, and 0.0–2.7 µg/l among children. The proportion of samples where mercury was not detected was 44.4% for blood, 38.0% for urine among adults, and 19.2% for urine among children.

Limitations. The conducted study took into account only the content of heavy metal (mercury) in vegetables and biological environments of the population.

Conclusion. Mercury contamination was confirmed by the results of post-operational analysis of vegetable products at the city-forming enterprise. Mercury levels exceeding the maximum permissible limit (0.02 mg/kg) were detected in 69.0% of vegetable samples (by 1.05–4.75 times). Median mercury concentrations in urine and blood among the surveyed population of the Usolsky district did not exceed permissible limits.

Compliance with ethical standards. The study was approved by the Local Ethics Committee of the East-Siberian Institute of Medical and Ecological Research, The study was conducted in accordance with the ethical principles of the World Medical Association Declaration of Helsinki (2013 edition), did not infringe on the rights of the study subjects, did not endanger them. All participants and their legal representatives gave informed voluntary written consent to participate in the study.

Contribution:
Zhurba O.M. – search for literature sources, data processing, text writing;
Merinov A.V. – search for literature sources, data processing, statistical processing, text writing;
Efimova N.V. – research concept and design, scientific consulting;
Katamanova E.V. – research concept, design and editing;
Savchenkov M.F. – research concept and design.
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 work was carried out within the framework of funds allocated for the implementation of exploratory and scientific research of the state task East-Siberian Institute of Medical and Ecological Research.

Received: October 30, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Given the relevance of air pollution, it is necessary to examine the effectiveness of projects aimed at improving environmental quality.

Objective. To assess the effectiveness of the “Clean Air” project using medical and environmental indicators, using the city of Bratsk as an example.

Materials and Methods. Data of monitoring for 2015–2024 in a city with a developed industrial and energy complex was analyzed. Health risks were characterized using hazard coefficients and indices (HQ, HI), relative risk of respiratory diseases. The indicators were calculated taking into account two periods, with 2022–2024 considered as the result of implementing a set of measures.

Results. In 2022–2024, the city saw a decrease in the content of 3,4-benzo(a)pyrene by 1.8 times, carbon disulfide by 3.2 times, nitrogen dioxide by 2.7 times, suspended matter by 1.9 times, and hydrogen fluoride by 1.7 times. This led to a decrease in the incidence of respiratory diseases in children: RR was 1.28 CI (1.19–1.37), the etiologic share of external factors (EF) is estimated at 21.8%, for ARI – 1.28 CI (1.22–1.34), EF = 21.7. According to the incidence of bronchial asthma and asthmatic status, two risk groups can be distinguished: 0–4 years (RR = 1.84; EF = 45.6) and 10–14 years (RR = 1.95; EF = 48.1).

Limitation. Uncertainties in the results are related to the specifics of using medical documentation reporting forms and insufficient epidemiological knowledge about the relationship between morbidity and air pollution.

Conclusion. To assess the effectiveness of the program, it is advisable to analyze the trend in airborne pollutant levels, taking into account seasonal changes.

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

Contributions:
Rukavishnikov V.S., Lakhman O.L. – study concept and design, editing;
Efimova N.V. – study design, data collection, writing, editing;
Mylnikova I.V. – statistical data processing, writing;
Bobkova E.V. – data collection, statistical data processing, writing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

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

Funding. The study had no sponsorship.

Received: October 29, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Water pollution with oil products poses a serious threat to human health. When oil and its derivatives enter water bodies, the natural ecosystem is disrupted, rendering the water unsuitable for drinking and household use. Ensuring biological safety is essential due to the ongoing adverse impact of pollution of aquatic components by various chemical factors on the formation of the environment’s microbiome and public health.

The aim of this study was to investigate the viability of the aquatic microbiome under conditions of increased oil product loads on water bodies.

Materials and methods. The state of microbial communities in the water of water bodies was studied under experimental conditions with the addition of petroleum products to river water: unleaded AI-95 gasoline and M-100 fuel oil. Gasoline was added to twenty eight experimental model reservoirs – at the level of MPC (0.1 mg/dm³), 10 MPC, 100 MPC, 1000 MPC and a suspension of potentially pathogenic test microorganisms Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and pathogenic microorganisms Salmonella typhimurium. Fuel oil was applied to 16 model ponds, creating a 1 cm thick film or suspension of droplets in the water column and suspension of Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, and pathogenic microorganisms Salmonella enterica subspecies enterica serotype enteritidis. The infectious microorganisms for model reservoirs was 10² CFU/dm³, 10³ CFU/dm³, 10⁴ CFU/dm³. The experiment to study the effect of gasoline on sanitary-indicative and pathogenic microorganisms lasted 14 days, fuel oil – 30 days.

Results. Concentrations of petroleum products up to 10 MPC inhibited the growth of total microbial counts and the sanitary indicator microorganisms E. coli and E. faecalis. Maintaining an associative link with pathogenic microorganisms for up to 12 days of exposure when gasoline spilled into water bodies and up to 20–31 day when fuel oil spilled droplets. Gasoline concentrations of 100× and 1000× MPC, as well as a fuel oil spill in water as a film, resulted in 100% mortality of E. coli and E. faecalis after 6 days of exposure. Elevated concentrations of petroleum products in water bodies resulted in a significant increase in the hydrocarbon-oxidizing bacteria Pseudomonas aeruginosa with prolonged contact time.

Limitations. The obtained experimental data will be confirmed by in-kind studies of water in reservoirs.

Conclusion. When significant concentrations of petroleum products enter a water body during emergency situations or the discharge of insufficiently treated wastewater from oil refineries, it is advisable to monitor the safety of water bodies using the sanitary indicator microorganisms E. coli and E. faecalis. In case of long-term release of high concentrations of petroleum products into water bodies, water safety monitoring should be carried out for the formation of hydrocarbon-oxidizing bacteria, including Pseudomonas aeruginosa.

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

Contribution:
Trukhina G.M. – concept and design of the study, analysis of obtained data, writing text, editing;
Borisova N.A. – concept and design of the study, data collection and analysis, writing text;
Sinitsyna O.O. – writing 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.

Funding. The study was conducted as part of the state program “Ensuring Chemical and Biological Safety of the Russian Federation for 2021–2024.

Received: November 21, 2025 / Revised: December 15, 2025 / Accepted: December 19, 2025 / Published: January 15, 2026

Provision of sanitary-epidemiological welfare for the country population largely depends on control for non-communicable diseases; among them, a substantial contribution belongs to arterial hypertension (AH) due to both its high prevalence and considerable proportion in the morbidity and mortality structure. Apart from the well-known risk factors, considerable influence on formation of AH can be exerted by changes in atmospheric pressure. It is advisable to identify key pathogenetic mechanisms of formation of AH upon changes in atmospheric pressure and indicators that describe them.This review covers materials presented in Russian and foreign publications, which are indexed in PubMed, Scopus, Google Scholar, CyberLeninka, and Elibrary.ru in 2010-2025 and focus on effects produced by atmospheric pressure on a rise in blood pressure (fifty five reports). The accomplished review has allowed establishing blood pressure to grow upon atmospheric pressure differences due to activation of the sympathoadrenal system (SAS) and renin-angiotensin-aldosterone system (RAAS) with a subsequent growth in cardiac output and heart rate (HR). When atmospheric pressure goes down, a decline in the vascular tone and partial oxygen density (ρO₂) are the initial segments; when it grows, arterial walls swell and spastic vasoconstriction occurs. Indicators for further profound analysis may include heart rate, cardiac output, blood pressure, biochemical indicators that describe SAS and RAAS activation, functional indicators that describe the state of the autonomic nervous system, ultrasound indicators to describe morphofunctional state of the heart and vessels, as well as hemoglobin oxygen saturation (SpO₂) under declining atmospheric pressure. Our results can be used in hygienic descriptions of effects produced by changes in atmospheric pressure on formation of AH within social and hygienic monitoring as well as for implementing branch activity plans with their focus on adaption to climate change within providing sanitary-epidemiological welfare of the country population.

Contributions:
Khasanova А.А. – study concept and design, collection and analysis of literature data, writing, and editing;
Zaitseva N.V., Shur P.Z. – research design, editing;
Ustinova О.Yu. – collecting and analyzing literature data, and 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: September 22, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Death is inseparable from the functioning of the biosphere and demonstrates its inherent connection to the presence of humanity on Earth. According to data from the end of 2024, with a total global population of 8.156 billion people, the average daily number of recorded deaths is 170,463, which amounts to 7,103 deaths per hour. An analysis of urbanized areas, which are home to 4.42 billion people, revealed a direct correlation between urban development and the management of burial sites. A historical retrospective shows that urban agglomerations, which have existed for millennia, have traditionally served as sites for interment. Currently, the territories of former burial grounds are used mainly as permanent burial zones, converted into park areas or built-up areas with green spaces. A study of the soil cover in the aforementioned territories revealed specific characteristics due to their original purpose and subsequent land-use transformations. All soils at burial sites are classified as necrosols and are characterized by the following features: turbation of the soil profile, enrichment of deeper soil horizons with phosphorus and carbon, deep mixing of the soil, and the presence of various artifacts and burial remains. In modern soil classification, there is no place for those soils that, after being used for burials, are utilized within built-up areas; they can only be characterized as “technogenic” or “other soils” without indicating the presence of former graves.

This article provides a review of foreign and Russian literature devoted to the study of cemetery soils, aiming to classify them according to their degree of impact on the environment and public health. The study did not include soils used for burial sites after the cremation of the bodies of the deceased in a crematorium or for burial sites in family vaults.

Contribution:
Ushakova O.V. – research concept and design, writing, editing;
Rakhmanin Yu.A. – research concept, editing;
Evseeva I.S. – research concept and design, collection of material and data processing, writing, editing;
Ibragimova S.Sh. – writing, 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 carried out as part of the State assignment.

Received: November 13, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. The formation of a healthy lifestyle is one of the priorities of the state’s policy in the prevention of chronic noncommunicable diseases, including arterial hypertension (AH), among the able-bodied population.

The aim of the study was to assess adherence to a healthy lifestyle (HLS) in the prevention of AH in workers of harmful industries.

Materials and methods. Individual preventive counseling was conducted, aimed at increasing adherence to healthy lifestyle and correcting risk factors, among one hundred thirty six AH workers of harmful industries. Adherence to a healthy lifestyle according to the “Healthy Lifestyle Profile” questionnaire and blood pressure (BP) indices were assessed at the initial consultation and after 3 years of the preventive program.

Results. 3 years after the start of the program, the proportion of employees who followed the recommendations on healthy lifestyle increased by 15–20% in the category of “good” adherence to healthy lifestyle and 5–7% in the category of “high” adherence to healthy lifestyle. There was an increase in scores on all scales characterizing the main components of healthy lifestyle: “Responsibility for health”, “Physical activity”, “Nutrition”, “Stress management”, “Inner growth”, "Interpersonal relationships”. The target BP levels (less than 135/85 mmHg) were achieved in 58% of the surveyed. The number of employees with a normal daily BP rhythm (“dippers”) increased from 45% to 61%. A significant effect of the components of healthy lifestyle (“Nutrition”, “Physical activity”, “Stress management”) on BP levels (r=0.57–0.61) was revealed.

Limitations. The assessment of adherence to a healthy lifestyle is limited by the number of surveyed workers of harmful industries exposed to noise and vibration, and the duration of observation.

Conclusion. The questionnaire based on the “Healthy Lifestyle profile” questionnaire can be used as a criterion for evaluating the effectiveness of hypertension prevention at the individual and group levels.

Compliance with ethical standards. The research program was approved by the Committee on Biomedical Ethics of the Federal Scientific Center of Hygiene named after F.F. Erisman (Protocol No. 16 of February 18, 2021). All participants gave informed voluntary written consent to participate in the study.

Contribution: All co-authors made an equal contribution to the research and preparation of the article for publication.

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

Funding. The study had no sponsorship.

Received: November 21, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Effects produced by occupational exposures on health of workers employed at the chemical productions have not been given sufficient attention.

The aim of this study was to establish and perform hygienic assessment of specific development of occupational and somatic diseases in workers employed at ammonia / carbamide production.

Materials and methods. We examined two hundred forty four workers employed at an ammonia/carbamide producing enterprise; the observation group was made of 165 production workers (aged 42.2±1.6 years; work records equaled 11.6±1.5 years) and the reference group included 79 administrative workers (42.9±2.8 years and 10.5±1.6 years accordingly, p=0.32–0.58). The groups were divided by age, work records, and occupations (p=0.13–0.97). Working conditions were assessed using sanitary-hygienic, chemical-analytical, and instrumental methods; workers’ health was assessed relying on the results obtained by medical-social surveys, general clinical, functional, instrumental, and laboratory tests.

Results. Adverse working conditions at the analyzed production are determined by exposure to noise level beyond their safe limits; ammonia, nitrogen and carbon oxides, aromatic hydrocarbons, and carbamide dust in workplace air; work intensity. Working conditions at administrative workplaces belong to the hazard category 1–2 (permissible). Diseases of the ear are a priority occupational pathology; priority somatic diseases include those of the endocrine, respiratory, and cardiovascular system. Main production workers face almost tenfold risk of diseases against administrative staff. Morbidity among auxiliary production personnel includes the same occupational and somatic diseases; however, their likelihood is twofold lower. Prevalence of priority pathologies is almost two times higher among main production workers aged younger than 45 years among their peers involved in auxiliary operations; the difference reaches 2.6 times in the older age group.

Limitations. The study results can be extrapolated only on workers employed in similar working conditions at ammonia/carbamide productions.

Conclusion. Longer work records have an apparent adverse effect on prevalence of occupational and work-related diseases in workers employed at main ammonia/carbamide production since they increase likelihood of such pathologies by up to 20 times when reaching 10 years and by up to 13 times when exceeding 10 years.

Compliance with ethical standards. The study was approved by the local ethics committee of Federal Scientific Center for Medical and Preventive Health Risk Management Technologies (the meeting report No.4 dated January 10, 2024) and accomplished in full conformity with the conventional research principles stated in the WMA Declaration of Helsinki (2013 edition). All participants gave informed voluntary written consent to participate in the study.

Contributions:
Ustinova О.Yu. – study design and writing the text;
Kostarev V.G., Nurislamova Т.V. – study design, data collection;
Vorobyeva А.А., Nosov А.Е. – writing the text, statistical data analysis;
Babina S.V. – statistical data analysis;
Ponomarev М.D. – data collection;
Ponomarev А.L. – data collection and statistical analysis.
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: September 23, 2025 / Revised: November 7, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Fatigue and occupational injuries are closely related to the influence of harmful and dangerous production factors, which can be identified through a questionnaire survey and the development of preventive measures based on employee opinions.

The purpose of the study. To assess the functional state in individuals working under the influence of harmful and dangerous production factors based on remote questionnaire data, and to propose measures to prevent fatigue and occupational injuries.

Materials and methods. The results of a questionnaire survey of thirty nine eight hundred seventy eight employees in 19 types of economic activity (104 occupational groups) were analyzed. The questionnaire included 39 questions divided into four research blocks: age, work experience, and occupational characteristics; risk factors related to physical and emotional stress; signs of fatigue, existing health problems, and information about injuries; assessment of the current system for preventing fatigue and injuries, and suggestions for improving it. The average values were calculated based on quantitative and categorical indicators, and the significance of the differences between the groups was assessed using the Fisher test.

Results. A questionnaire survey showed a change in the functional state in employees in response to the influence of harmful and dangerous production factors, especially those over the age of 45 years. The change in the funcional state (fatigue and stress) under the influence of physical and emotional stress was recognized by the respondents as the main cause of injury (about 40% in both fields) and was considered more significant than technical and managing causes. More than half of the respondents in the production sector and a significant portion in the non-production sector considered the existing measures for preventing fatigue and injury to be insufficiently effective.

Limitations. The results are valid for this sample, but given the large number of respondents, they may be applicable to the general cohort of employees. It should also be noted that the respondents’ responses are subjective.

Conclusion. Recommendations have been developed to reduce fatigue and injuries, taking into account the specific features of the production and non-production sectors.

Compliance with ethical standards. The study did not require the conclusion of the Ethics Committee. All participants gave informed voluntary written consent to participate in the study.

Contribution:
Tovstiy M.A. – research concept and design, data collection, and editing;
Mazhkenov S.A. – research concept and design, questionnaire development, data collection, writing the text;
Zibarev E.V. – research concept and design, methodology of the study, questionnaire development, and editing;
Kravchenko O.K., Nikonova S.M. – data processing, questionnaire development, 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.

Funding. The study was carried out as part of a government assignment.

Received: October 22, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Currently, the metabolic syndrome (MS) prevalence among the adult population worldwide is about 25%, or more than a billion people. Among individuals in occupations with hazardous vibrations, MS occurs in 34.6% of cases. The most common diagnostic criteria are dyslipidemia, with hypercholesterolemia recorded in 52% of patients with vibration disease (VD). However, data on the occupational risk of these disorders are lacking.

Materials and Methods. A total of 241 workers in vibration-prone occupations with a diagnosis of VD was examined. All workers were assessed for the presence of MS components according to diagnostic criteria.

Results. In patients with MS and VD caused by exposure to local vibration, triglyceride (TG) levels as a diagnostic component of MS are higher than in patients with VD caused by combined exposure to local and general vibration. A high degree of occupational causation of MS was established (RR=2.1 (1.6–3.1), EF=52.4%), disturbances in the concentration of high-density lipoprotein cholesterol (HDL-C) (RR=3.1 (1.3–7.6), EF=67%); and close to average degree of occupational causation – high levels of low-density lipoprotein cholesterol (LDL-C) (RR=1.4 (0.96–2.12), EF=29%).

Limitations. The cross-sectional design included male subjects aged 40 to 60 years with vibration syndrome from exposure to local or combined vibration.

Conclusion. A high degree of occupational risk was established for MS, as well as low HDL-C levels, and a near-moderate degree of occupational risk for high LDL-C concentrations.

Compliance with ethical standards. The study was conducted in compliance with the ethical standards of the Helsinki Declaration (last revised) and Order No. 200n of Russian Federation Health Ministry the dated April 1, 2016. Conclusion of the local ethical committee of the East-Siberian Institute of Medical and Ecological Research No. 2 dated December 21, 2023. All participants gave informed voluntary written consent to participate in the study.

Contribution:
Kudaeva I.V. – the concept and design of the study, editing, statistical processing, writing text;
Chistova N.P. – collection and processing of material, statistical processing, writing text.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

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

Funding. The study had no funding and was performed within the framework of the funds allocated for exploratory scientific research of East-Siberian Institute of Medical and Ecological Research.

Received: November 11, 2025 / Revised: November 14, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Occupational chronic obstructive pulmonary disease (OCOPD) is a serious cause of disability. The SARS-CoV-2 infection has caused a new problem: a combination of OCOPD and postcovid syndrome. The task of an occupational pathologist is to identify markers of disorders in such patients and develop personalized methods of treatment and rehabilitation.

Material and methods. The clinical and functional parameters in ninety men with chronic obstructive pulmonary disease (COPD) of occupational and non-occupational origin were analyzed: 30 OCOPD men with COVID-19, 30 OCOPD men without COVID-19, and 30 men with non-occupational COPD and COVID-19. Dyspnea (Borg scales, mMRC, CAT), spirometry (FVC, FEV1, FVC/FEV1) and quality of life (SF-36) were assessed. The three groups were compared using the Kraskel–Wallis test and the Mann–Whitney method in a pairwise comparison.

Results. The CAT scores in group 1 are higher than in groups 2 and 3 (p<0.017). The degree of dyspnea on the mMRC scale in group 1 was significantly higher (p=0.01). On the Borg scale, scores in group 1 before and after exercise were higher than in group 3 (p<0.001) and group 2 after exercise (p=0.006). The FEV₁ and FEV₁/FVC spirometry indices in group 1 are worse than in group 2 and 3 (p<0.001 and p=0.001; p=0.016 and p=0.007, respectively). The physical and mental components of the SF-36 quality of life in group 1 are lower than in group 2 (p=0.014 and p=0.003).

Limitations. There are quantitative limitations due to the gender of the surveyed and the design of the study.

Conclusion. A study of the clinical and functional parameters in patients with occupational and non-occupational COPD has shown that those who have suffered from COVID-19 have more pronounced symptoms: cough, sputum, shortness of breath, fatigue, sleep and breathing disorders, decreased physical activity. They also score higher on the Borg scale, which indicates to a lower stress tolerance.

Compliance with ethical standards. The study was approved by the local Ethics Committee of the East Siberian Institute of Medical and Ecological Research (Minutes of meeting No. 2 dated 02/21/2023), conducted in accordance with the generally accepted scientific principles of the Helsinki Declaration of the World Medical Association (ed. 2013). All participants gave informed voluntary written consent to participate in the study.

Contribution:
Maraev M.D. – research concept and design, data collection and processing, text writing and editing;
Katamanova E.V. – writing, editing;
Beygel E.A. – writing, 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 research was carried out within the framework of exploratory scientific research “Development of approaches to the treatment and medical rehabilitation of patients with comorbid postcovid syndrome and military personnel injured in combat” (Reg. №. 123032000011–5).

Received: November 6, 2025 / Revised: November 18, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Working conditions in lead production are known to be associated with exposure to various harmful chemicals in the workplace air. Erythrocytes are constantly exposed to various stress factors causing irreversible damage and leading to the cell death. Thus, the antioxidant system, capable of inactivating reactive oxygen species (ROS) and eliminating the associated damage, plays an important role in protecting this type of cells. Glutathione is a significant part of this system, while glutathione-S-transferase Pi (GSTP1-1) is present in many mammalian tissues and the most common intraerythrocytic isoenzyme, representing 95 % of the total pool of glutathione-S-transferases.

The purpose of the study was to establish the effect of GSTP1 gene polymorphism and its expression on the hemoglobin level in workers engaged in secondary lead processing.

Materials and methods. To find the relationship between the rs1695 polymorphism of the GSTP1 gene and the blood hemoglobin level, three hundred twenty nine male workers of a secondary lead smelter were included in the study. DNA was isolated from whole blood samples by the salt method according to the standard technique, the rs1695 polymorphism of the GSTP1 gene was determined using real-time PCR with fluorescent probes. In 54 smelters of the refining department, we isolated RNA using the ExtractRNA reagent and determined the gene expression level using real-time PCR.

Results. The analysis of the effect of the GSTP1 genotype on the hemoglobin level among the workers of various departments demonstrated the mutant genotype (G/G) to be associated with lower hemoglobin levels in workers in the refining department. The study of the GSTP1 gene expression level in workers of the refining department (refiners) and the comparison group in 2022 revealed that the expression level was statistically lower in the exposed workers.

Limitations. Ethnicity was not determined in this study.

Conclusions. We established a relationship between the GSTP1 gene polymorphism and the hemoglobin level in the refiners of the secondary lead smelter. We also found a decrease in the level of GSTP1 gene expression in the blood of workers exposed to occupational risk factors, indicating additional inhibition of detoxification processes at the level of gene expression.

Compliance with ethical standards. The study was conducted in accordance with ethical principles of the WMA Declaration of Helsinki and approved by the Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers (protocol No. 1 of February 26, 2021). All participants gave informed voluntary written consent to participate in the study.

Contribution:
Shaikhova D.R. — data processing, statistical analysis, draft manuscript preparation, editing;
Kikot A.M., Bereza I.A. — data collection and processing, editing;
Sutunkova M.P. — study conception and design.
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: November 5, 2025 / Revised: November 18, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Radiolysis products formed during radiation processing of foods are a central focus in the safety evaluation of food irradiation technologies. This review systematizes data on the mechanisms of radiolysis of the main food components (lipids, proteins, carbohydrates, vitamins) and the formation of specific low-molecular-weight compounds, including 2-alkylcyclobutanones, furans, organic acids, and other markers of radiation exposure.

The toxicological characteristics of these compounds are examined in detail based on experimental studies from 1960 to 2025, including “in vitro” and “in vivo” models, multigenerational and subchronic experiments, clinical observations, and regulatory evaluations by FAO/WHO/IAEA, EFSA, FDA and national authorities. Particular attention is paid to 2-alkylcyclobutanones as specific radiolysis products of lipids, as well as to furan and acrylamide, which are formed predominantly during thermal processing.

The paper provides an overview of international regulatory approaches to irradiated foods (EU, USA, countries of Asia, Latin America, Africa and the Middle East), emphasizing that regulation is based mainly on process control (dose, list of authorized products, labelling) rather than on establishing maximum permissible concentrations of individual radiolysis products. There are described methods of analytical control, including chromatographic, spectroscopic, luminescent, and non-destructive approaches (hyperspectral imaging, multi-omics tools). It is shown that, when regulated irradiation doses are observed, the concentrations of radiolysis products do not pose an additional health risk compared with conventional technological processes.

Contributions:
Kuzmin S.V. – article concept and preparation;
Rusakov V.N. – material collection and processing, writing, 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 had no sponsorship.

Received: October 27, 2025 / Revised: November 22, 2025 / Accepted: December 2, 2025/ Published: January 15, 2026

Introduction. It is quite relevant to assess effects produced on children by chemical factors (exemplified by nickel) associated with specific point single nucleotide replacements in detoxification genes.

Materials and Methods. Children in the observation group (n=44) are exposed to airborne nickel amounting to 1.28 average annual MPC; children in the reference group (n=45) live in a “relatively clean” area (lower than 0.1 average daily MPC). The study relied on using mass spectrometry, enzyme-linked immune assay, allergosorbent assay, flow cytometry, and real-time PCR.

Results. Inhalation exposure to nickel (up to 1.28 average daily MPC) at a dose of 0.00207 mg/kg per day resulted in a 1.73-fold increase in blood contamination in children in the observation group compared to the reference group. In the observation group, a statistically significant (p<0.05) increase in the number of CD4⁺CD25⁺CD127^–-regulatory cells (by 1.5 times), cortisol concentration (by 1.7 times), the level of specific IgE antibodies to nickel (1.3 times) and an increase in the number of CD4⁺ lymphocytes (by 10%) were found relative to the values obtained in the reference group; polymorphism of genes controlling detoxification and apoptosis processes was identified – CYP1A1, GSTP1, TP53 and CPOX (RR=1.39–1.96) (RR=1.96, 95% CI: 1.79–2.12; RR=1.61, 95% CI: 1.31–1.97; RR=1.39, 95% CI: 1.05–2.02 and RR=1.76, 95% CI: 1.53–2.01, respectively). Based on the results of modeling using the “exposure marker – effect marker” system, there was established a relationship reflecting the hyperproduction of nickel-specific IgE, total IgE, and cortisol when nickel was present in blood (RR = 2.42, 95% CI: 1.37–4.27; RR = 2.39, 95% CI: 1.54–3.79; RR = 4.60, 95% CI: 1.05–20.11, respectively).

Limitations. The study limitations include a limited sample size in the examined children groups and sex-related imbalances; this requires additional research to verify the findings.

Conclusion. Therefore, children exposed to airborne nickel (1.28 average daily MPC) and with polymorphism of candidate apoptosis and detoxification genes (CYP1A1, GSTP1, TP53, CPOX) face a risk (RR=1.39–1.96) of excessive nickel bioexposure (2.6 times higher). This affects on immune regulation (suppressive and helper activity of cell clusters, nickel hypersensitivity – IgE), and adaptation (hypercortisolemia). So, we can recommend verified indicators as markers of effect and sensitivity for preventing allergic diseases in children living in environments destabilized by pollutants (using nickel compounds as an example).

Compliance with ethical standards. The study protocol was approved by the Local Ethics Committee of the Federal Scientific Center for Medical and Preventive Health Risk Management Technologies, meeting report No. 7 dated December 19, 2022. All participants and their legal representatives gave informed voluntary written consent to participate in the study.

Contribution:
Dianova D.G. – concept and design of the study, writing text;
Dolgikh O.V. – concept of the study, data analysis and interpretation, editing;
Kazakova O.A., Shirinkina A.S. – data collection and processing, and creating tables.
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: September 24, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Exposure to inorganic mercury salts contributes to immune system dysfunction and may lead to the development of allergic diseases in children.

Objective. To determine the level of sensitization to food allergens in children living in the ecological trouble territory.

Materials and methods. A total of one hundred ninety one child aged 11 to 16 years were examined: Group 1 consisted of individuals with mercury excretion, while Group 2 (comparison) consisted of individuals without it. Total and allergen-specific immunoglobulin E (IgE) levels were determined in all children. Results were compared using the Mann–Whitney U test, and odds ratios and 95% confidence intervals were calculated. Analysis of the relationship between specific IgE concentration and mercury excretion was performed using multiple nonlinear regression with a direct stepwise procedure for incorporating features.

Results. In the children group without elevated total IgE levels, the values for all studied specific immunoglobulins did not differ statistically significantly between the groups. With an elevated concentration of total IgE in children with mercury excretion, the specific IgE content to the cow’s milk antigen was statistically significantly higher than in the comparison group. Children from group 1 with an elevated total IgE level were characterized by a higher frequency of high concentrations of specific IgE to the chicken egg protein antigen (OR = 1.67; 95% CI (1.02–10.59)) and milk (OR = 1.29; 95% CI (1.09–13.30)), as well as the presence of a statistically significant relationship between the elevated specific IgE concentration to mixed poultry meat antigens and mercury contamination.

Limitations. Children aged from 11 to 16 years, whose parents and they themselves permanently resided in Usolye-Sibirskoye and the surrounding area.

Conclusion. Children living in areas with accumulated environmental damage and excreting mercury exhibited higher levels of sensitization to antigens from chicken egg whites, milk, and mixed poultry meat.

Compliance with ethical standards. The study was conducted in compliance with the ethical standards of the Helsinki Declaration (last revised). Conclusion of the local ethical committee of the East-Siberian Institute of Medical and Ecological Research No. 1 dated December 21, 2023. Parents and/or legal representatives of minor children signed voluntary informed consent for the examination.

Contribution:
Kudaeva I.V. – the concept and design of the study, editing, statistical processing, writing text;
Starkova A.S., Prokhorova P.G. – collection and processing of material;
Kucherova N.G. – collection and processing of material, statistical processing.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Acknowledgment. The authors express their gratitude to I.V. Mylnikova, senior researcher at the Laboratory of environmental and hygienic research, for her assistance in organizing the examination of children, and to O.V. Bukshina, research assistant at the Laboratory of analytical ecotoxicology and biomonitoring, for conducting research on determining mercury in urine.

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

Funding. The study had no funding and was performed within the framework of the funds allocated for exploratory scientific research of East-Siberian Institute of Medical and Ecological Research.

Received: October 31, 2025 / Revised: November 17, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

The Russian Science Citation Index and CyberLeninka, as well as the Internet resources of international organizations (WHO, etc.) and regulatory agencies of the countries listed in the review (US Environmental Protection Agency, etc.) with a search depth from 2018-2025 revealed differences in the approaches of global regulators to minimizing potential risks from the use of chlorpyrifos (CPFS), despite the European Union’s proposal to include it in the list of persistent organic pollutants (POPs) of the Stockholm Convention after new information emerged about its potential danger to the unborn child. To date, a complete ban on CPFS has been introduced by countries with a cold or temperate climate (Canada, EU), as well as exporting countries trading with the EU (Vietnam, Indonesia, Malaysia, Nepal, Peru, Thailand, Turkey, Chile, Sri Lanka). At the same time, the Russian Federation, along with the United States of America and Australia, have significantly restricted the use of CPFS. The use of chlorpyrifos in agriculture remains unchanged in Mexico, China, and Brazil. Despite the affordability of some alternative chemical plant protection products available for some applications of CPFS, there is no complete analogue with the same broad spectrum of action on the market, which may deter developing countries from restricting or banning CPFS until it is officially included in Annex A of the Stockholm Convention on Persistent Organic Pollutants, despite the potential risks it may pose to the safety of the unborn child.

Contribution:
Rakitskii V.N., Veshchemova T.E. – concept and design of the study, collection and analysis of literary data, writing the text;
Chkhvirkiya E.G., Masaltsev G.V. – concept and design of the study, collection and analysis of literary data, 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.

Funding. The study was carried out within the framework of the industry programs of Rospotrebnadzor “Scientific justification of the national system for ensuring sanitary and epidemiological well-being, health risk management and improving the quality of life of the population of Russia” (2021-2025).

Received: October 13, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. 2,2-Dimethoxy-2-phenylacetophenone is a widely used photoinitiator applied in various industries, including the production of varnishes, paints, dental materials, and coatings. However, despite its widespread use, the toxicological properties of this compound remain to be insufficiently studied.

The aim of this study. To investigate the toxicity and potential hazards of 2,2-dimethoxy-2-phenylacetophenone.

Materials and methods. Toxicological studies were conducted to assess the effects of the substance on warm-blooded animals. The experiments included evaluation of acute toxicity via oral, dermal, and inhalation exposure routes; evaluation of cumulative properties; assessment of irritation effects on the mucous membranes of the eyes and intact skin; as well as dermal resorptive and sensitizing effects.

Results. The study showed 2,2-dimethoxy-2-phenylacetophenone to belong to hazard class 4 (low hazard substances) when administered orally (DL₅₀ > 5000 mg/kg). In acute dermal exposure tests, no animal mortality was observed (DL₅₀ for rats > 2500 mg/kg). The substance does not exhibit skin irritant properties but can cause irritation to the mucous membranes of the eyes. No dermal resorptive effect was detected. The substance is not an allergen and does not exhibit cumulative properties. 2,2-Dimethoxy-2-phenylacetophenone is characterized by low volatility. During the study of acute inhalation toxicity, the maximum attainable concentration was 500 mg/m³. Therefore, the substance can be classified as moderately hazardous by the inhalation route of exposure.

Limitations. Due to the low volatility of 2,2-dimethoxy-2-phenylacetophenone and the technical limitations of the inhalation system, the study of acute inhalation toxicity was conducted at only one concentration.

Conclusion. The results of the toxicological studies indicate 2,2-dimethoxy-2-phenylacetophenone to belong to hazard class III (moderately hazardous substances). Considering its widespread use, presence in industrial emissions, and the consequent exposure risk to populations living near such facilities, further studies are recommended to evaluate its chronic toxicity, long-term effects, and carcinogenic potential.

Compliance with ethical standards. The study was conducted in accordance with generally accepted ethical guidelines for the use of laboratory animals and was approved by the Bioethics Committee of the Centre for Strategic Planning of the Centre for Strategic Planning of the Federal medical and biological agency, (meeting protocol No. 5 dated 09/18/2024).

Contribution:
Fedotova L.A. – study concept and design, editing;
Mamonov R.A. – study concept and design, editing;
Pechnikova I.A. – study concept and design, collection and processing of material;
Lebed-Sharlevich Ya.I. – writing text and data analysis, collection and processing of material;
Manaeva E.S. – writing text and data analysis, collection and processing of material;
Potapchenko T.D. – writing text and data analysis, collection and processing of material;
Belyaeva N.I. – collection and processing of material;
Gollandtseva A.I. – collection and processing of material;
Nemtseva Yu.S. – collection and processing of material;
Tyurina I.A. – collection and processing of material;
Fedortsova D.Yu. – collection and processing of material;
Fedortsov I.A. – collection and processing of material;
Bolekhan V.N. – 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 had no sponsorship.

Received: April 22, 2025 / Revised: August 6, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Accumulated hazardous waste containing hazardous pollutants are potential and actual sources of adverse impact on the environment, which contributes to a significant deterioration in public health and reduces the quality and life expectancy. During the operation of the industrial facility of Usolye-Sibirskoye Chemical Plant LLC (Usolsky District), mercury levels in the bodies of people living near secondary contamination sites were found to be above acceptable limits. Only 42.8% of people had mercury concentrations within the normal range. The incidence of disease in the population of Usolye-Sibirskoye was studied. According to the literature, the causes of the increased incidence were environmental pollution and the long-term effects of exposure to harmful industrial factors.

The aim of the study is to investigate neurophysiological and immunobiochemical changes in industrial workers exposed to mercury through inhalation and in the adult population, depending on the distance of the place of residence from the source of contamination.

Materials and methods. Group 1 included long-term workers exposed to mercury (mean age 49.2 ± 4.4 years); group 2 included individuals exposed to chronic mercury intoxication in the late period (CMI, mean age 53.4 ± 4.3 years); group 3 included individuals living less than 3 km from the industrial site (mean age 47.4 ± 3.9 years), group 4 included individuals living 3‒5 km from the industrial site (mean age 48.1 ± 4 years). The subjects underwent electroencephalography, electroneuromyography, and measurements of serotonin, dopamine, BDNF, and concentrations of neurotropic antibodies to myelin basic protein (MBP), voltage-dependent calcium channels, and dopamine receptors.

Results. In group 1, there were found moderate changes in brain bioelectric activity with high β1-activity, dysfunction of the midline structures, focal changes in the frontal-temporal areas; in group 2, slow-wave activity of the Δ-range in the frontal areas; In group 1, the impulse conduction velocity along the ulnar nerve in the elbow joint and along the tibial nerve decreased; in groups 2 and 3, a decrease was observed in the median and ulnar nerves, respectively; in group 4, an increase in the proximal-distal ratio. In group 1, serotonin and BDNF decreased, in group 2, dopamine, antibodies to voltage-dependent calcium channels, MBP increased, BDNF decreased; In groups 3 and 4, dopamine, antibodies to dopamine receptors, and BDNF decreased.

Limitations. A correlation between neurotransmitter levels and EEG and ENMG has not been established.

Conclusion. Individuals not exposed to the toxicant developed moderate general cerebral changes, including polyrhythmic polymorphic activity, high levels of slow-wave activity, changes in the normal distribution of fundamental rhythms, a focus of pathological activity, and dysfunction of midline structures. Changes in sensory and motor axons, an imbalance in the neurotransmitter system, and antibody synthesis were also recorded. A correlation between neurotransmitter levels and EEG and ENMG has not been established.

Compliance with ethical standards. Conclusion of the LEK of the Federal State Budgetary Scientific Institution «East Siberian Institute of Medical and Environmental Research», No. 1 dated 02/21/2023. All participants gave informed voluntary written consent to participate in the study.

Contribution:
Rusanova D.V. – study concept and design, data collection and processing, statistical processing, writing text, structuring an article, editing;
Katamanova E.V. – data processing, statistical processing, writing text;
Kudaeva I.V. – study concept and design, data collection and data processing, writing text;
Lakhman O.L. – study concept and design, editing;
Protasova E.N. – data collection and data processing, statistical processing, writing text;
Prokhorova P.G., Starkova A.S. – 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.

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

Received: October 7, 2025 / Revised: November 11, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Growing human impacts on the environment together with ongoing climate change make provision of sanitary-epidemiological wellbeing of the population a truly vital issue. Health risks associated with chemical ambient air pollution and caused by respiratory diseases can grow during heat waves, among other things, due to greater susceptibility of the respiratory system to chemical exposures.

The aim of this study was to quantify respiratory health risks upon exposure to chemical ambient air pollution during heat waves in an industrially developed region (the Perm region) used as an example.

Materials and methods. Likelihood of respiratory diseases was calculated by using logistic regression models. The calculations were based on the following indicators: average daily air temperatures (abnormally warm days), depersonalized incidence rates, and average daily concentrations of chemicals in ambient air in cities in the Perm region.

Results. Risk levels caused by exacerbated asthma and chronic bronchitis among the regional population and associated with such ambient air pollutants as nitrogen oxide, xylenes, and sulfur dioxide were found to be higher during heat waves against their levels without allowing for abnormally warm days. When chemical levels are below MPC in ambient air, the risks are within their acceptable ranges and a period, during which they grow up to unacceptable levels, is between 5 and 22 abnormally warm days depending on a chemical and age group. When chemical levels grow up to MPC, health risks become unacceptable over a period from 1 to 16 abnormally warm days.

Limitations. Logistic regression models were built using data on settlements in only one region of the Russian Federation (the Perm region).

Conclusion. Ambient air pollution during heat waves creates elevated health risks caused by exacerbation of respiratory diseases. This should be considered when developing preventive activities within programs for population adaptation to climate change.

Compliance with ethical standards. The study did not require approval by the local ethics committee (it was accomplished using data provided by the regional office of the Mandatory Medical Insurance Fund).

Contributions:
Zaitseva N.V. – study concept and design, Editing the text;
Shur P.Z. – study concept and design, Editing the text;
Khasanova А.А. – data collection and analysis, writing and editing the text, mathematical data analysis;
Chigvintsev V.М. – mathematical data analysis.
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: October 22, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Drinking water is an important strategic resource. Monitoring for the epidemiological safety of water bodies for sanitary and virological indicators involves concentrating large volumes of water (from 10 to 100 liters). The need to study samples of such volume requires revision, modernization, and unification of sanitary and virological methods and, above all, optimization of concentration processes, modes and methods of sample preparation, to increase their efficiency and reduce the time from the moment of water sampling to the beginning of its study.

The aim of the study is to compare the efficiency of virus sorption using three different concentration methods: a cartridge with a glass fiber filter; an anion exchange resin; on a flow membrane filter module with tangential-radial movement of liquid with positively charged microfiltration polyamide membranes in microfiltration mode.

Materials and methods. Test virus – polio vaccine virus Sabin 1 in concentrations of 2, 3, and 4 lg TCID₅₀/10 l. Experimental reservoirs were prepared on the basis of dechlorinated tap water.

Results. All three methods of sample preparation are suitable for the qualitative determination of the polio virus in tap water at a concentration of 2 lg TCID₅₀/10 l and higher.

Limitations. The effectiveness of the three methods of concentrating viruses from water was assessed using a qualitative method. The study was conducted using model reservoirs created on the basis of tap water from the centralized water supply network of Moscow.

Conclusions. The method of concentrating viruses using the filtration method on a fiberglass cartridge filter for sample preparation can be recommended for use in conducting sanitary and virological research of water for the presence of pathogens of intestinal infections of a viral nature along with concentration methods using anion exchange resin; on a flow membrane filter module with tangential-radial fluid movement with positively charged microfiltration polyamide membranes in the microfiltration mode.

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

Contribution:
Abramov I.A. – study concept and design, experiments, literature and experimental data analysis, visualization, writing, design and editing of the manuscript;
Nedachin A.E., Tymchuk S.N. – study concept and design, experiments, editing of the manuscript;
Karbovnicaya K.V. – experiments.
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 conducted under the agreement 01-12/03-24 dated March 19, 2024 with CJSC ROSSA.

Received: February 13, 2025 / Revised: September 9, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Introduction. Acetaldehyde is hazardous to the environment, and therefore its content in the air, water and soil is regulated. The maximum permissible concentration in soil is set at 10 mg/kg, but there are no regulatory and methodological documents for its determination in soil.

Objective of the study. Determination of acetaldehyde in soil by gas chromatography in combination with static headspace analysis.

Materials and methods. The studies were carried out on samples of sod-podzolic, sandy, and urban soils, as well as ordinary chernozem, collected in the Moscow, Kursk, Murmansk, and Tver regions. Acetaldehyde was detected using a hardware and software complex based on a Chromatec-Crystal 5000.2 gas chromatograph (Chromatec, Russia) with a flame ionization detector (FID) and an external Lab Hut HT 200 H-200 equilibrium vapor dispenser (HTA s.r.l., Italy), with a DB-624 capillary column (Agilent, USA) 60 m, 0.53 mm, 3 µm.

Results. A large array (more than a thousand) of soil samples was analyzed (list the characteristics of the soils). Acetaldehyde was present in all samples, the concentration of which ranged from 0.04 mg/kg to 6.0 mg/kg. The dependence of the FID signal on the sample mass, its humidity, time, and temperature of thermostatting was studied. The optimal sample mass when using 20 ml vials is 2 g, and the sample humidity for most soil types was found to be 20%. Analysis of soil samples by the EPA 5021 method with the addition of 10 cm³ of a modifying solution or reagent water to 2 g of soil leads to very low values ​​of the chromatographic peak areas, or their absence. Extraction of acetaldehyde directly from the soil sample allows increasing the sensitivity of the detection by 10–60 times.

Limitations. Calibration graphs constructed using different types of soils may have different slopes, therefore, for the purpose of unification, it is advisable to use aqueous solutions, although this approach may introduce a systematic error in the analysis results.

Conclusion. A method for detecting acetaldehyde in soil using gas chromatography with a flame ionization detector in combination with static headspace analysis has been developed. The detection limit was 0.04 mg/kg.

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

Contribution:
Nekrasova L.P. – concept and design of the study, conducting experimental studies, writing the text, collecting material and processing data, editing;
Sbitnev A.V. – conducting experimental studies, collecting material and processing data;
Filimonova E.I. – conducting experimental studies, processing results, statistical processing;
Kuleshova O.Yu. – conducting experimental studies, collecting material and processing data;
Vodianova M.A. – collection of material, processing of results.
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: September 18, 2025 / Revised: October 10, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

In 2025, we mark the 100^th anniversary of the birth of Professor Konstantin Ivanovich Akulov – a hygienist, public health manager, Honored doctor of the RSFSR, participant of the Great Patriotic War, and Chief state sanitary doctor of the RSFSR (1965–1990). The article presents K.I. Akulov’s path in scientific and practical service. K.I. Akulov led efforts to eliminate the cholera epidemic in Astrakhan (1970), managed and developed measures to combat AIDS (1986–1990), and managed the response to the consequences of the Chernobyl nuclear power plant accident in the western regions of Russia (1986–1990). He also participated in the investigation of numerous emergencies. K.I. Akulov combined his practical activities with teaching. He was a talented lecturer, prepared “Teaching and Methodological Materials for Independent and Classroom Work of Students” (1984), and authored the textbook “Public Health” (1986) for the sanitary-hygiene departments of the country’s medical universities.

Contribution:
Popova A.Yu. – the concept and design of the study, editing;
Podunova L.G. – the concept and design of the study, collection and processing of material and writing a text;
Kuzmin S.V. – the concept and design of the study, writing a text;
Kuchma V.R. – the concept and design of the study, writing a text.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version

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

Funding. The study had no sponsorship.

Received: November 11, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026

Received: November 11, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026