Prevalence of Hearing Loss and Its Associated Occupational Risk Factors among Tema Oil Refinery Workers

Abstract

Background: Hearing loss is a major health concern considering its permanent or irreversible effects on people. Noise-induced hearing loss develops gradually as workers are constantly exposed to noise. Some operations in the oil refineries generate noise exceeding the permissible exposure limit (PEL) of 85 dB (A). Fortunately, hearing loss associated with one’s occupation is preventable unlike age-related hearing loss which cannot be prevented. Many occupational bearing toss studies in oil refineries have confirmed the negative impacts of noise exposure on workers bearing. The World Health Organization (WHO). National Institute of Occupational safety and Health (NIOSH), and Occupational Safety and Health Administration (OSHA) have recognised industrial noise as a major health hazard in many occupational settings worldwide. In Ghana, occupational hearing loss has been reported to be due to occupations of the workers. The majority of the previous studies conducted have been in the informal industrial sector. The emphasis of this study was to investigate hearing loss associated with work-related factors and age of workers and recommend effective control measures to reduce or eliminate if possible all factors that may lead to hearing loss of workers. Currently, there is no published research work on occupational hearing loss among workers in the oil refinery in Ghana. Objectives: The aim of this study was to determine the prevalence of hearing loss and its associated work-related factors and age among Tema Oil Refinery workers. Method: This was a cross-sectional study design utilizing secondary audiometric and noise level monitoring data from the company's medical and environmental monitoring records. Audiometric data was obtained for a total number of 359 subjects who work at different locations within the refinery noted for generating high noise intensity. Results: For both crude and adjusted odds ratio's, a one age significantly increased the odds of hearing loss by 37 and 39%, p<0.001 respectively likewise a one year increase in working year significantly increased the odds of hearing loss by 38 and 23%, p<0.001 and p= 0.004 respectively. The study revealed some differences between right and left ears of those who with hearing loss by 27.3%. The results also indicated that, the adverse noise effect is generally bilateral and symmetrical by 45.4%. Conclusion: the findings demonstrate that, age and years of work were definitely factors to be considered as very important for staff recruitment into factory jobs and work location of the industrial establishment did not matter.