Occupational Noise Exposure and Self-Reported Hearing Loss amongst Workers in Primary Coffee Processing Factories in...

About 15 million people are directly and indirectly involved in Ethiopian coffee production. Coffee workers in Ethiopia may be exposed to workplace noise due to industrial machines, but the extent of their exposure and the prevalence of hearing loss are currently unknown.

This study aimed to evaluate noise exposure, identify factory and task-related conditions that significantly increase noise levels and assess self-reported hearing loss amongst coffee workers in Ethiopia.

A cross-sectional study was conducted in 12 primary coffee processing factories in three Ethiopia regions. A total of 60 machine room workers were involved in full-shift, personal noise exposure measurements. The results from an observational checklist and statistical analysis of noise measurement data were used to identify the determinants of personal noise exposure. Additionally, 130 randomly selected workers participated in interviews on self-reported hearing loss, yielding a 100% response rate.

The average daily noise exposure amongst machine room workers was 96.3 decibels A-weighted (dBA). Ninety-two per cent of the measurements exceeded the occupational exposure limits of 85 dBA, and 40% exceeded 90 dBA. The presence of more than one huller machine was associated with a 4.5 dBA increase in noise exposure. Approximately, 53% of the machine room workers reported at least one symptom of hearing loss. Workers with more than 10 years of experience had nearly three times higher risk of hearing loss symptoms than those with less than 5 years of experience, after adjusting for age and other factors (adjusted prevalence ratio = 2.9, 95% confidence interval: 1.4-5.9).

These findings highlight the significant health risk of noise exposure faced by workers in primary coffee factories, with over half of these workers reporting symptoms of hearing loss, and most of them being exposed to noise levels above the recommended limit value. Implementing interventions to reduce noise levels amongst coffee workers is essential to protect their hearing well-being.