Assessment of noise impact on coal mine workers including way to/from workplace

Abstract

Purpose. Determination of the noise induced permanent threshold shift for a coal miners in five main working professions, taking into account the noise impact on the way to the workplace and back based on data obtained from personal sound level meters. Methodology. A strategy is selected for measuring the level of noise exposure at workplaces No. 3 per workday (GOST ISO 9612-2016) in a coal mine. Personal sound level meters were attached to the miners shoulders; they measured the noise level on the way to the workplace, during the work shift (8 hours) and on the way back. The processing of the measurement results was carried out on the basis of a quantitative assessment of the noise impact on workers according to the noise induced permanent threshold shift (NIPTS). The NIPTS values were calculated for a period from 3 to 30 years for 5 main professions, taking into account the noise impact when moving to the workplace and back. Findings. The values of the equivalent noise level at miners workplaces of are determined, which are 15 to 20 dBA above the maximum permissible equivalent level (80 dBA). Based on the results obtained, a constant shift in the hearing threshold was forecast for workers of five occupations with seniority of 3 to 30 years. A reduction in the hearing threshold of a sinker will amount to 25 dB in 30 years, which corresponds to the occupational disease Stage 3. Originality. Constant displacement of the hearing threshold for workers in coal mines, caused by the effect of an increased noise level during the journey to the place of work and back, was revealed. Practical value. It was found that in order to prevent the development of an occupational disease (sensorineural hearing loss) in underground miners, it is necessary to measure the noise level by using personal sound level meters for an 8-hour working day, taking into account the way time to the workplace and back. Noise exposure assessment should be based on a continuous decrease in the hearing threshold.