Occupational exposure level of ELF magnetic fields assessment in 330 kV switchyards of hydro-plants and gas-plants stations in North-Central Nigeria

Abstract

The ardent quest for electricity that affects virtually all human activities has evolved the speculation of its adverse effect on human health when exposed to the associated electromagnetic field. Occupational exposure levels of the density of extremely low frequency (ELF) magnetic field in five 330 kV switchyards of Hydro-plants and Gas-plant with similar infrastructures were investigated, assessed and analysed. The entire switchyard measurement of ELF magnetic field were performed with reference to three observation heights of 1.0, 1.5 and 1.8 m above ground level via spot measurements techniques in segmented manner using Extech 480826 triple-axis EMF metre in conformity to IEEE standards, and occupational exposure computed from the mean of the three observation heights for each spot. The analysed results using Welch ANOVA SPSS package demonstrated occupational significant differences of (p < .001) between 330 kV switchyards of Shiroro Hydro-plant and Geregu Phase II Gas-plant, significant differences of (p = .045) between switchyards of Geregu Phase I Gas-plant and Geregu Phase II Gas-plant, and also significant differences of (p < .001) in occupational exposure was demonstrated between switchyards of Jebba Hydro-plant, Kainji Hydro-plant when separately compared to Geregu Phase I and Geregu Phase II Gas-plants. However, non-significant differences occurred between switchyards of Shiroro Hydro-plant and Jebba Hydro-plant, Kainji Hydro-plant and Geregu Phase I Gas-plant, and Jebba Hydro-plant with Kainji Hydro-plant. This study has revealed the prevalence of electropollution in occupational environment and variation in the strength between switchyards personnel might encounter at instant of the measurements