Working conditions for electrical personnel under using shielding equipment in the warm season of the year

Introduction. Near overhead power lines in occupational conditions where the power frequency electric field strength exceeds the maximum permissible limit, the staff used shielding personal protective equipment of the Ep type may have additional thermal load on the body’s functional state type during warm weather.Material and methods. Hygienic assessment of occupational conditions was in the sanitary protection zone of 330 kV, 500 kV, and 750 kV overhead power lines. In addition to power frequency, electric and magnetic fields assessment, there was studied the action of climatic conditions on volunteers using personal protective equipment too. The volunteers’ thermal state was evaluated using the change in the body’s heat content (heat accumulation) during work as integral indicator of the human thermal state.Results. The power frequency electric and magnetic fields hygienic evaluation shown maximum permissible limit to be exceeded by more than two times by electric field, while there was no exceedance of the magnetic field maximum permissible limit during the entire work shift at the study sites. During work with personal protective equipment the significant increase in the heat accumulation indicator was observed when air temperatures exceeded the upper limit of permissible values.Limitations. The study was limited by the environmental conditions and the relatively small sample size of volunteers.Conclusion. The occupational hygienic assessment of power, frequency of electric and magnetic fields showed the electric field maximum permissible limit to be exceeded at both study sites, classifying as harmful (Class 3.1) occupational condition and necessitating the use of personal protective equipment. The assessment of occupational condition class by microclimatic parameters using shielding personal protective equipment the heating environment conditions should consider the workers’ thermal state indicators.Compliance with ethical standards. The study was approved by the local ethical committee of the Izmerov Research Institute of Occupational Health (meeting protocol No. 3 dated 23.03.2022), and the Helsinki Declaration of the World Medical Association. All participants gave informed voluntary written consent to participate in the study.Contribution: Perov S.Yu. — the concept and design of the study, collection and processing of material, editing; Burmistrova O.V. — the concept and design of the study, collection and processing of material, editing; Dremin A.I. — the concept and design of the study, collection and processing of material, 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.Acknowledgement. The study had no sponsorship.Received: October 7, 2024 / Revised: November 5, 2024 / Accepted: December 3, 2025 / Published: April 30, 2025

power frequency electric field, electric staff, human thermal state, shielding personal protective equipment, classification of occupational condition