Worker's Hearing Threshold Changes in a Steel Industry: 5 Years Follow-up

Abstract  Introduction: Sound is one of the most important harmful factors in the work environment. The physiological effects of sound on humans appear gradually in the long run. In spite of industrial progress, exposure to excessive noise is still one of the health problems facing workers in the world. Materials and Methods: This descriptive-cross sectional study was designed and implemented. The surveyed 121 workers were a rolling steel industry with a 5-year-old audiometry from 91 to 95 years old. The audiometric test of these workers was carried out over a 5-year period by a reader device. The results of their audiometry were extracted and examined by observing the ethics of their medical records. Data analysis was performed using SPSS 21 software. For statistical analysis, T-test and Wilcoxon Signed Ranks Test were used. Findings:  According to the results of this study, the work in the steel industry due to sound contact causes a gradual increase in hearing loss due to sound, which increases the hearing threshold in workers with a significant work record.