Comparative physiological and hygienic assessment of personal protective equipment properties in various configurations from power frequency electric field

Abstract

Modern working conditions of employees can be characterized by the presence of harmful factors of the working environment, including physical factors that often have a complex effect on the human body during the working shift. One of the main harmful factors of the working environment for electrical personnel is the electric field of industrial frequency, which is protected by personal protective equipment (shielding kits), which exerts an additional thermal load on the body of personnel when working outdoors in the summer. The aim of the study was a comprehensive assessment of personal protective equipment of various configurations and their impact on the thermal state of a person in a heating environment to select the optimal configuration. The objects of study were screening suits consisted of overalls, jacket and trousers, jacket and semi-overall. For screening suits protective properties test the possible working conditions were simulated power frequency electric field levels from 5 to 80 kV/m (grounding) and 10-100 kV/m (on wire potential). The physiological and hygienic assessment of personal protective equipment involved 3 male volunteers. Their body constitution was selected according to typical differences of workers. Volunteers dressed in screening suit had physical activity at air temperature 34.8±0.3°C, relative humidity 48.0±3.0% and air mobility 0.15 m/s. Before and during the study parameters were recorded: skin temperature on 11 parts of body surface, clothes temperature, heart rate, body temperature in the ear canal, points of heat and moisture sensation and moisture loss was determined after the study. Before physical activity and after recovery period volunteers were measured blood pressure. Studies of the protective properties of three sets of personal protective equipment have shown that the best protective characteristics in comparison with the other sets have a jacket and half - overalls, the worst - a jacket and trousers. The results of the physiological and hygienic evaluation of screening kits showed individual differences in the thermoregulatory reactions of all volunteers when using different sets of personal protective equipment. At the same time, large amounts of heat accumulation in the body, a high heart rate and its change, as well as a higher moisture perception score were observed during the operation of the jumpsuit. As a result of research, the optimal configuration was chosen jacket and half-overalls, which has a moderate thermal load on the human body and has the best protective characteristics. From the point of view of the lowest voltage of thermoregulation reactions, it can be recommended to use a shielding kit as part of jacket and trousers.