Introduction: The recent decline in natural reproduction in the Russian Federation has made maintaining human reproductive potential–an indicator of the maximum possible rate of population growth in the absence of limiting environmental influences–of high sociodemographic significance. However, the actual population growth rate is restricted by factors that impede its unlimited growth.

   Objective: To identify factors determining the decline in the reproductive potential of the human population.

   Materials and Methods: We reviewed regulatory acts, literature sources, and data from previous studies indicating a decline in reproductive capacity for medical and social reasons using analytical and descriptive methods.

   Results: When considering the actual reproductive potential of the human population, three components can be identified that determine it: the reproductive component of the sociomedical resource of the society, reproductive losses, and reproductive behavior. The actual size of the reproductive component of the medical and social resource of the society is made up of men and women of fertile age (15–49 years old) free from medical factors affecting reproductive capacity, namely: excluding women after bilateral ovariectomy, salpingectomy, and/or hysterectomy; with medical reasons for termination of pregnancy, and with diseases complicated by infertility; men and women with congenital or acquired genital defects that impede reproductive function, sterilized and/or infertile. Reproductive losses contribute significantly to the decline in reproductive potential. Reproductive behavior also affects both the reproductive component of the sociomedical resource of the society and reproductive losses.

   Conclusion: Identifying and eliminating the negative impact of these factors will facilitate growth of the current reproductive potential.

   Background: Psychomotor development in early childhood is influenced by both biological and environmental factors. Stunting represents a major biological risk, whereas parenting style is an important environmental determinant that may modify developmental outcomes.

   Objective: To examine the possible moderating effect of parenting style on the relationship between nutritional status and psychomotor development.

   Materials and Methods: A cross-sectional study was conducted in rural Magelang Regency, Central Java, Indonesia, from September to December 2024. Participants were 115 mother and child pairs (mean child age = 13.4 months, 47.8 % female). The dependent variable was psychomotor development, while the independent variables were nutritional status and parenting practices. Child age, sex, and maternal knowledge about child development and nutrition were covariates.

   Results: The results showed a substantial (OR = 12.85) but not statistically significant (p = 0.094), association between parenting style and nutritional status (stunting). We revealed an interaction pattern indicating that parenting style had an impact on the association between stunting and psychomotor delay. The only factor that significantly predicted psychomotor development was childhood age (p = 0.029).

   Conclusion: Although the multiplicative interaction term was not statistically significant, the findings suggest that parenting style may modify the relationship between stunting and psychomotor development. Larger prospective studies are needed to confirm these findings and clarify the underlying mechanisms.

   Introduction: A balanced diet plays a key role in maintaining health of coal mining workers at high risk of injury and associated occupational stress, physiological changes related to heavy physical underground labor, disruption of biological rhythms due to irregular shifts, and disorders induced by habitual high-calorie eating patterns.

   Objective: To establish biochemical parameters of the lipid profile in miners by dietary patterns to identify alimentary risk factors for dyslipidemia.

   Material and Methods: In March 2025, we conducted a cross-sectional study involving 157 coal miners from the Kemerovo Region. Workers aged 18 to 65 years with at least a year of current employment were eligible for inclusion. Venous blood was collected for testing the lipid profile while the diet was assessed using a modified Food Frequency Questionnaire.

   Results and Discussion: The comparison of subgroups revealed statistically significant differences in triglyceride levels between underground workers and surface service personnel (Me 2.14 vs 1.59, p = 0.014). We observed a significant effect of the duration of underground work on total cholesterol (age-adjusted p = 0.04). Diet analysis revealed high consumption of red meat and fried foods but a rare intake of fish, fruits, vegetables, and berries among miners. Correlations were found between red meat (pork/beef) consumption and blood levels of triglycerides and high-density lipoproteins. Dyslipidemia was more frequent in those who preferred pork. The dietary patterns associated with dyslipidemia were sweet + meat + salt and meat + low vegetable intake.

   Conclusions: An unhealthy diet increases the risk of dyslipidemia in miners, thus necessitating comprehensive measures, including personal recommendations on food choices given nutrigenetic characteristics, improvement of worker catering, and a change in approaches at the regulatory level.

   Introduction: The study was conducted to assess health risks posed by soil pollution to the population of Kolchugino, one of the old industrial centers of the Vladimir Region.

   Objective: To assess carcinogenic and non-carcinogenic health risks to the population of the city of Kolchugino caused by soil pollution with heavy metals and arsenic from metal works.

   Materials and Methods: Health risk assessment was conducted in accordance with Russian Guidelines R 2.1.10.3968–23 based on soil concentrations of gross forms of As, Co, Cr, Cu, Ni, Pb, and Zn measured in the city of Kolchugino in 2023. Both carcinogenic and non-carcinogenic risks from oral, inhalation, and dermal exposures were calculated by three age groups
(children under 7 years of age, children aged 7–17 years, and adults aged 18 years and over). Statistical processing and mathematical calculations were performed using Microsoft Excel.

   Results: We established that values of the total carcinogenic risk were acceptable and ranged from 4.92×10–5 to 6.99×10–5. Ingestion was the priority route of exposure contributing the most to the carcinogenic risk and the total hazard index. The highest hazard indices were estimated for children under 7 years of age. Contamination of urban soils with heavy metals and arsenic posed the highest risks of disorders of the skin and of the nervous, cardiovascular, respiratory, and endocrine systems in the population of Kolchugino. The limitations of the study were related to exposure estimates, reference doses, and slope factors.

   Conclusion: Our findings show that carcinogenic and non-carcinogenic health risks posed by soil contamination in the industrial city of Kolchugino are within acceptable limits. The central nervous system, especially in children, is the most vulnerable to non-carcinogenic effects of heavy metals.

   Introduction: Organic carbon is one of the most important parameters monitored in water treatment, as its presence poses the risk of generation of halogenated organic byproducts during decontamination. Different treatment techniques are used to purify drinking water. Given the dynamic changes in water composition, the issue of selecting the most effective chemical reagents is becoming increasingly important.

   Objective: To establish total organic carbon and chloroform levels during water treatment depending on the reagents used (ammonium sulfate, chlorine, coagulants, or flocculants).

   Materials and Methods: We conducted a four-year monitoring of water temperature and levels of the total organic carbon in the Chusovaya River, during treatment before delivery to the urban distribution network, and calculated long-term and seasonal means. Chloroform and residual chlorine concentrations were measured in drinking water. We assessed water quality and effectiveness of water treatment. The relationship between doses of the reagents and quality parameters was established using correlation analysis.

   Results: The mean level of total organic carbon in the water source was 20.1 ± 1.3 mg/dm3; water treatment reduced it by 32.3 %. The mean chloroform concentration in drinking water was 0.039 ± 0.002 mg/dm³. No interplay was found between reagent doses and total organic carbon levels in drinking water; yet, we observed a positive correlation between total organic carbon levels in the water source, the doses of chlorine and flocculant 2 (a nonionic polyelectrolyte with a bulk density of 660 kg/m³) used for treatment and chloroform levels in drinking water. The use of the aluminum chlorohydrate coagulant, flocculants 1 (a nonionic polyelectrolyte with a bulk density of 830 kg/m³) and 3 (anionic polyacrylamide with a bulk density of 750 kg/m3) demonstrated the best results in removing total organic carbon from water.

   Conclusion: A decrease in total organic carbon concentrations was observed during water treatment with the aluminum chlorohydrate coagulant and flocculants with higher bulk densities being the most effective. A statistical correlation was found between source water quality parameters, doses of chemical reagents used, and the resulting chloroform levels in drinking water.

   Introduction: The presence and spread of antibiotics and antimicrobials in the natural environment is a serious concern worldwide.

   Objective: To develop and test a method for determining sulfonamides in water using high-performance liquid chromatography with mass-spectrometric detection (HPLC/MS-MS).

   Materials and Methods: The study involved samples of various types of water (drinking water, surface and groundwater, swimming pool water, treated wastewater, etc.) collected in 2024–2025 in an industrial city. Over 150 samples of various water types were analyzed during the development, establishment of metrological characteristics, and testing of the methodology. Laboratory testing was carried out using high-performance liquid chromatography with mass spectrometric detection. Conditions for the effective extraction of sulfonamides from water were established using solid-phase extraction with Oasis HLB cartridges.

   Results: We developed a selective and highly sensitive method for determining sulfonamides in water using high-performance liquid chromatography–mass spectrometry in the concentration range from 3 to 4,000 ng/dm³ with a determination error of 46–50 %. Conditions for the efficient extraction of sulfonamides from water using solid-phase extraction in Oasis HLB cartridges and a 0.2 % solution of formic acid in acetonitrile as an eluent have been elaborated. The average extraction rate of sulfonamides from various types of water ranged from 75 % to 100 %. As a result of testing the method for determining sulfonamides in various types of water samples, the qualitative presence of six out of seven determined compounds was established in 75 % of the samples, of which sulfanilamide, sulfathiazole, and sulfadimethoxine were detected above the lower limit of detection in the concentration range from 4 to 110 ng/dm³. No exceedances were detected.

   Conclusion: The study results confirm the feasibility of using high-performance liquid chromatography combined with solid-phase extraction for testing sulfonamides in water at levels representative of their actual concentrations in aqueous matrices.

   Introduction: In recent years, lithium has increasingly been viewed as a conditionally essential element, with its low levels in the body potentially leading to disorders of the nervous and cardiovascular systems. Data on lithium intake in the Russian population is insufficient, although the diseases related to its deficiency remain a pressing public health issue.

   Objective: To establish the intake of lithium with food and drinking water in the adult population of the Omsk Region.

   Materials and Methods: Dietary lithium intake was assessed in a representative sample (n = 506) of the regional population aged 18–83 years. Daily intake was determined using a food frequency questionnaire and the original food composition database containing the results of testing lithium levels in food products and drinking water.

   Results: The median dietary intake of lithium was 115.5 (95 % CI: 88.6–150.5) μg/day, with no significant differences found between age and sex groups. The proportion of the adult population with the critically low Li intake (< 100 μg/day) was 37.2 ± 2.1 %. No individuals with lithium intake above the provisional daily level of 1 mg/day were identified. The contribution of food and drinking water to the dietary intake of lithium was 98.5 % and 1.5 %, respectively. The main food sources were beverages (47.7 %), vegetables (26.4 %), dairy products (6.7 %), and such specific individual beverages and
dishes as tea (20.9 %), coffee (20.5 %), beer (8.1 %), and soups (4.5 %).

   Conclusions: Our findings indicate the potential deficiency of lithium in a significant part of the regional population, which requires extensive research on the lithium content in food products and assessment of its dietary intake in various population groups.

   Introduction: In the context of occupational exposure to biological agents, healthcare personnel require appropriate multimodal training for effective and safe work, one of the directions of which is building new staff competencies.

   Objective: To determine the conditions necessary for the formation of a competence profile of healthcare professionals that ensures adaptation to high biological health risks based on the example of a hand hygiene and antisepsis system.

   Materials and Methods: The study was conducted in 2023–2025 at a multidisciplinary medical center. Professional competencies of the personnel in hand hygiene and antisepsis were improved using the authors’ patented methodology that includes the conditions for proper procedure implementation, regular training and certification, and continuous multilevel audit. The results of the implementation of the methodology were monitored using online surveys, overt and covert observations. The importance of supra-professional competencies in enhancing adherence to hand hygiene compliance was assessed by the level of emotional intelligence using a short test by D.V. Lyusin.

   Results: The effectiveness of the approach to building professional competencies of employees in hand hygiene and antisepsis has been demonstrated. The findings show that the system requires regular refresher training at least quarterly. Improvement of the emotional quotient (EQ) served as a resource for increasing employee commitment to standards. Employees with high and very high EQ scores demonstrated greater adherence to the established regulations.

   Conclusion: The study presents a systematic approach to adapting the competence profile of employees to biohazards and epidemiological challenges based on the development of significant professional and supra-professional skills using current opportunities and technologies.