Elemental Composition of Children's Hair as an Indicator of Technogenically Altered Territories in Eastern Transbaikalia

BACKGROUND: The Transbaikal Territory is characterized by an excess, deficiency, and/or unfavorable ratios of numerous macro- and microelements in environmental objects, determined by the region’s geochemical features. These factors directly affect the elemental status of the human body and contribute to the development of pathological conditions. AIM: The work aimed to investigate the characteristics of the elemental status of children and adolescents living in areas with varying levels of anthropogenic load. METHODS: It was a cross-sectional study. Inclusion criteria: children and adolescents aged 6–14 years, permanently residing in the study area since birth; no intake of vitamin–mineral complexes or medications; natural hair condition. Two groups were identified depending on the presence of sites of accumulated environmental damage near settlements: group 1 included children and adolescents residing in settlements without such sites; group 2 included children and adolescents living near tailing ponds and mine waste dumps. To assess the characteristics of elemental status, the chemical composition of hair was analyzed using total reflection X-ray fluorescence on an S2 Picofox spectrometer. RESULTS: The study included 148 children and adolescents residing in the Transbaikal Territory. Statistically significantly higher concentrations of most essential, conditionally essential, and toxic chemical elements were found in the biosubstrate of group 1 (n=97), living in settlements characterized by a significant number of thermal power facilities, railway infrastructure, industrial enterprises, and motor vehicles, compared with group 2 (n=51), residing in settlements located in close proximity to tailing ponds (p 0.001). Statistically significantly elevated levels of zinc and lead and decreased levels of essential elements (selenium, iodine, cobalt) were observed in the hair of group 2 compared with group 1. Correlation analysis of the quantitative content of different chemical elements in the biosubstrate revealed extensive interrelationships, reflecting the influence of both geological formations and anthropogenic pressure in the residential areas of study participants. CONCLUSION: The assessment of macro- and microelement content and ratios in hair provides an opportunity to evaluate the geochemical characteristics of territories with different natural and technogenic conditions and to develop preventive measures to avoid disturbances in the elemental status of the population.