Assessment of Workers' Occupational Exposure to Noise and Hearing Loss in One of the Cement Factories

Abstract

Background: Noise is one of these factors and it is considered as a concern through the world. The purpose of this study is to provide information about the rate of noise-induced hearing loss (NIHL) among workers in one of the cement. Methods: 283 workers were randomly selected from different production units in a cement factory. Equivalent Sound Level (Leq) was measured by using a Casella CEL-320 ‎ dosimeter and Sound Pressure Level (SPL) was measured by using a TES-1358 sound level meter (SLM) (sn: 090717269), with high accuracy. Audiometric tests were conducted by using an AVA C88 audiometer. Collected data were analyzed by using SPSS.16 software and statistical tests. Results: The mean Hearing threshold limit (HTLs) ‎ at frequencies (3 and 4 KHZ) in the study group is significantly higher than the control group (P <0.001). There was a significant difference between the mean HTLs in the left and right ear at all frequencies, except for the frequency of 500 HZ. At higher frequencies (3-8 KHZ), the difference between the mean HTLs ‎ in both ears is more evident and it has significantly increased, compared to lower frequencies (0.5-2 KHZ). Conclusion: Long-term occupational exposure to noise has the potential to cause hearing loss in cement factory workers. Therefore, it is necessary to perform effective measures, such as utilizing technical and engineering techniques and procurement and effective use of hearing protection devices in order to prevent the prevalence of hearing loss in units with high exposure risks.