Neurophysiological and immunobiochemical changes in workers exposed to mercury and the general population

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

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