Risk assessment of public transport drivers’ noise exposure and noise induced hearing loss in ulaanbaatar city

Abstract

Background: 1.3 billion people worldwide suffer from hearing loss due to noise; around 22% of these cases are related to the workplace. Occupational hearing loss is an irreversible condition that harms the sensory cells of the auditory system. Aim: The study aims to measure the noise exposure level of public transport drivers and compare it with clinical symptoms to determine the risk of hearing loss. Measure the noise level of public transport drivers and compare it with the standard. Determining the risk of hearing loss by detecting noise-induced clinical symptoms Materials and methods: A cross-sectional study was conducted, and noise exposure measurements were taken by SVANTEK 104 TES 1350A noise level meter as required by the MNS 6768:2019 standard from 8 am to 10 am, 1 pm to 3 pm, and 5 pm to 7 pm, three times per day for a week, in 63 buses according to the work schedule of public transport drivers, from “Baruun 4 zam” to “Zuun 4 zam” (3.6 km). Clinical symptoms were collected by a questionnaire. Results were processed using SPSS 26 software. P-values < 0.05 were considered significant for statistical analysis. Employees who worked in the workplace for less than 5 years and had congenital hearing loss were included in the exclusion criteria. Results: A total of 35 people participated in the study, excluding 11 drivers who did not meet the criteria. Regarding the gender of the respondents, 89% were male (n=24), and 11% were female (n=11); the average life age was 44 (±9.6). The average working hours were 14.4(±2.3) hours, 5.7(±1.1) days per week. A total of 63 vehicles were measured for noise, and the hourly weighted average value was 92.24 dBA, exceeding the maximum allowable level of MNS 6768:2019 by 7.24 dBA. There was a statistically significant (p=0.018) association between years of work in public transportation and hearing loss. Conclusion: According to our research, the workplace noise level of public transport drivers is higher than the maximum allowable level, and hearing loss is directly related to working time in the workplace. Therefore, there is a high risk of occupational hearing loss, and there is an urgent need to implement a hearing protection program.