Relationship between noise pollution and hearing loss among workers in Sarkhoon Gas Refinery

Introduction: Occupational noise exposure induced hearing loss is recognized as one of the most harmful factors in industries. Hearing loss is one of the 10 top works–related diseases. This study is to determine the existence of noise pollution in the workplace and probability of its hearing injury among exposed workers in Sarkhoon refinery in 2008, Bandar Abbas, Iran Methods: In this cross-sectional and analytic study, First, noise polluted units (spl>85dB) were determined. Then, 41 workers of the industry were recognized and selected for further specialist visit and audiometric test. Also, unexposed workers from other non-noisy units were collected as the control group. Furthermore, a noise dosimeters test was done for all cases due to the results of noise exposure pattern. Results: Dosimeter test results demonstrated high level of noise (min=146% to max=782%) and audiometric results showed hearing loss in high frequencies in noisy units. Tests results also showed that 48.7% of the exposed workers showed left ear hearing loss, 46.3% of them showed indications of right ear hearing loss and 43.1% of them suffered from hearing loss in both side ears. In addition, there is a significant and positive relationship between increase in age and years of working with the hearing loss of left and right ear in both case and control groups. Conclusion: Since Sarkhoon gas refinery includes some noise polluted units as well as the increasing hearing loss problems of the workers (due to age and working years), effective noise control measures are suggested to prevent economic, health and environmental damages.