Linear regression models are traditionally used to estimate the relationship between chemical exposures and biomarkers. Still, they have several considerable limitations: they fail to consider heterogeneity of a population, do not adequately describe non-linear dependences and are not effective when correlated predictors are used. The aim of this study was to develop a methodological approach to verifying and using probabilistic models that describe the ‘biomarkers of exposure – biomarkers of effect’ relationship based on Kullback – Leibler (KL) divergence. This is an integral quality measure, which makes it possible to objective compare linear and non-linear models. A pilot sample was used to build several models: a linear model, ridge-regression, second-degree polynomial model, GAM, Random Forest, and XGBoost. KL-divergence was calculated for each model between the actual and predicted distribution of three blood indicators: neutrophils, eosinophils, and cortisol. The linear regression showed extremely high KL-divergence and the XGBoost yielded the best result. Q–Q (quantile-quantile) graphs revealed some discrepancies in distribution tails, which indicated that the sample was heterogeneous and stratification was necessary. The suggested approach makes it possible to objectively compare models and select the most adequate structure of the relationship. A feedback signal system was developed based on the built models; it used three scenarios (yellow, orange, and red) for automatic communication with services responsible for controlling quality of environmental objects in case serious deviations from safe standards were found in biomarkers in the population. The key advantage is that the method is easily scaled to cover any number of tests (biochemical, immunological, or genetic) and any set of pollutants without any changes in its basic logic. This makes the method a universal instrument for the system for social and hygienic monitoring.
Introduction: Population of the major industrial regions is exposed to multiple airborne pollutants. Actual exposure levels are verified by biomonitoring, which takes into account age and sex characteristics and pollutant metabolism patterns as a basis for establishing exposure-response relationships. Objective: To identify age- and sex-specific patterns and features of contamination of body fluids in the population exposed to airborne chemicals from emissions of diverse local industries. Materials and Methods: The study was conducted in five urban agglomerations noted for high ambient air pollution levels caused by the release of emission components from non-ferrous metallurgy, fuel energy, and wood processing facilities, and four populated areas without such emissions. Bodily fluids (blood and urine) sampled from 1,939 children aged 4–7 years, 408 children aged 8–14 years, and 901 adults aged 18–54 years were tested for 14 contaminants. The exposure assessment was based on instrumental monitoring data and emission dispersion calculations for 2016–2024. In this study, we used the Student’s t-test, Fisher’s t-test, Kruskal–Wallis test, and regression analysis. Results: Air quality monitoring data revealed up to 5.8 and 2.8-fold annual limit exceedances for benzo[a]pyrene and gaseous fluorides in the industrial areas, respectively, whereas emission dispersion calculations showed those for chromium trioxide and copper (up to 2.9 and 15.5 times, respectively). Biomonitoring findings confirmed population exposures and helped reveal the following age- and sex-specific patterns in pollutant distribution: accumulation of manganese, copper, nickel, and chromium in blood of children was up to 2.6 times higher than that in adults; urinary excretion of aluminum and fluoride ions in adults was almost twice as high as in children, and blood benzo[a]pyrene levels in girls and women were up to 4.5 times higher than those in men and boys. Conclusions: Biomonitoring specifies the real exposure load. Sex- and age-specific patterns of biological fluid contamination take into account individual characteristics of pollutant accumulation and clearance, which is essential for objective assessment of cause-and-effect relationships within the exposure–response system. Profiles of bodily fluid contamination are specific for individual components of airborne chemical exposure.
Introduction. The most important reasons for the progression of eye diseases in children, in addition to genetic factors, is insufficient artificial lighting in classrooms. Creating a light environment that is safe from a hygienic point of view is an important task of managing the learning process in a preschool institution.The purpose of the study: studying the influence of artificial lighting on the visual analyzer in children and hygienic assessment of the formation of health risks caused by eye diseases during the provision of education and training services in preschool educational institutions.Materials and methods. A retrospective analysis of measurements of artificial lighting in a preschool institution over a long-term period and forms of medical statistical reporting were performed. Measurements of artificial illumination were carried out in group cells of preschool institutions. Observation/control groups were formed and the pathological incidence of eye diseases in children was assessed. Correlation analysis was applied, relative risk (RR) was calculated and health risk was calculated using categorization of risk levels.Results. Exceeding the level of illumination to the hygienic standard (HS) statistically significantly increases the likelihood of developing general pathological diseases of the eye and its adnexal apparatus in children (RR = 3.2; CI = 1.6–6.4); a value below the HS determines a negative trend in the development of these diseases (RR = 1.4; CI = 0.6–3.1). The quantitative value of the health risk corresponds to the alarming level from exposure to LED and fluorescent lighting (7.0 ∙ 10–⁴; 6.0 ∙ 10–⁴, respectively), which is subject to periodic monitoring and requires additional preventive measures.Limitations. The conduction of the study in preschool educational institutions limits the possibility of extrapolating the research results to other types of educational institutions that differ in other conditions for the provision of services for the upbringing and education of children.Conclusion. Artificial illumination, both at the HS level and exceeding it, can cause a risk to the health of the visual analyzer in children. In this regard, it is advisable to establish the HS of artificial illumination in preschool institutions in the form of a range of values.Compliance with ethical standards. An ethical review was not required for this work.Contribution of the authors: Shur P.Z. — concept and design of the study, editing; Redko S.V., Lir D.N., Fokin V.A., Shtina I.E. — collecting and processing material, writing text, compiling a list of references. All co-authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.Funding. The study had no sponsorship.Conflict of interest. The authors declare no conflict of interest.Received: November 11, 2025 / Accepted: April 24, 2026 / Published: July 28, 202
Ambient air pollution with polycyclic aromatic hydrocarbons (PAHs) remains an urgent hygienic issue in residential areas exposed to motor transport emissions. Traditional gross dust monitoring that does not allow for fractional distribution of highly hazardous substances sorbed on dust particle surfaces leads to underestimation of actual exposure and associated health risks. The aim of this study was to establish peculiarities of distribution of priority PAHs in ambient fine-dispersed dust fractions in a residential area influenced by a motorway and essence of their bioaccumulation in experimental animals as well as to assess associated health risks. A field experiment involving inhalation exposure of Wistar rats (32 h) was accomplished in an area influenced by a large motorway (4800 vehicles/h). Dust fractions (PM1 – PM10) were sampled by the cascade method; suspended particles, by gravimetry. PAHs were identified in ambient air, solid particles and biological samples by HPLC; blood particles were identified by scanning electron microscopy (SEM). Non-carcinogenic health risks were assessed using the hazard quaintest and hazard index (HQ, HI); carcinogenic risk (CR), the total benzo(a)pyrene toxicity equivalent in conformity with the Guide R 2.1.10.3968-23. Ambient PAH levels did not exceed average daily MPC in the study area but were still 1.4–44.7 times higher than in the reference area. We revealed sub-micron distribution of the priority xenobiotic as benzo(a)pyrene was per 44.7 % associated with PM1 fraction. Non-carcinogenic risk (HI = 0.503) and carcinogenic risk (CR = 2.15∙10-6) posed by PAH mixture were permissible but associated with benzo(a)pyrene predominantly in PM1 (up to 44.0 %) per 97.3 % and 88.8 % respectively. SEM confirmed particles sized between 1.1 and 2.9 µm in blood and organs of the experimental animals. Blood benzo(a)pyrene levels were 29.4 times higher than in the control group. The chemical was found to accumulate in the lungs, liver and kidneys; anthracene and pyrene, in the spleen (up to 9.2 times higher against the control). We did not find naphthalene or 2-metyl naphthalene in organs. High permeability of the PM1 fraction through the air-blood barrier was proven in the experiment as well as its role as the main vector of PAH (predominantly benzo(a)pyrene) introduction into the bloodstream and parenchymatous organs. Our findings substantiate the necessity to introduce mandatory hygienic control of PM1 and benzo(a)pyrene in their structure. We recommend 0.002 mg/m³ as the safe level of chronic inhalation PM1 exposure. The analysis is limited to PAHs and does not consider contributions made by metals in the structure of fine-dispersed dust fractions.
Human-induced chemical burdens are growing persistently at the moment bringing relevance to development of structure and contents of the national information support for health risk assessment. This reflects the development potential of Russian science-based information system necessary for health risk analysis and is also relevant for supporting assessment, prevention and mitigation of risks associated with negative effects produced by chemical exposures on human health. This study provides the results of reviewing contents of up-to-date information databases that contain indicators for assessing human health risks associated with exposure to adverse chemicals in the environment. These results taken into account, we have determined basic trends in development of information support for health risk assessment in Russia. They include developing a system for reference values; providing each component in information support with substantiating materials; adding uncertainty categories to indicator values for risk assessment; clarifying effects produced by chemicals considering their toxicity pathways; including indicators of the Concentration – Response function and parameters of the Exposure – Response mathematical models; supplementing the information database with data about biomarkers of exposure, effects and sensitivity with their quantitative characteristics; including tolerable daily intake (TDI) doses along with reference doses (RfD) for assessing health risks upon oral introduction with food. The suggested structure of information support is quite promising for creating a Russian digital database as an integral component in the intellectual system for supporting decision-making on provision of sanitary-epidemiological wellbeing of the country population. Implementation of the outlined trends will raise quality and reliability of health risk assessments, reduce uncertainty, and provide transparence and reproducibility of calculation procedures. This corresponds to the tasks aimed at preventing and minimizing risks associated with negative effects of chemical exposures, providing better protection for the population and the environment as stipulated in the Order by the President of the Russian Federation No. 97 dated March 11, 2019.
