Assessment of Occupational Noise Exposure and Hazard Profiling in Local Sawmills and Rice Mills: Implications for Worker Safety in Jalingo Metropolis

This study assessed occupational noise hazards in selected sawmills and rice mills in Jalingo, Taraba State, Nigeria. Noise levels were measured across multiple operating hours over three consecutive days at each facility using a calibrated sound-level meter. To reflect the region’s 12-hour shifts, shift-adjusted permissible exposure limits (PELs) were calculated using the NIOSH 3 dB exchange rate. Findings indicate that noise exposure remains a major hazard in these small-scale processing industries. Gadanboboji Rice Mill recorded an average noise level of approximately 89 dB(A), exceeding the WHO limit of 85 dB(A). By comparison, New CBN Road Rice Mill and Muphido Rice Milling Company remained within acceptable limits. Among the six rice and sawmills assessed, five exceeded the adjusted PEL of 83.2 dB(A), with peak exposures ranging from 92.3 to 104.6 dB(A). Workers reported high rates of tinnitus, temporary threshold shifts, and difficulty hearing, along with non-auditory impacts such as stress and sleep disturbances. Engineering and administrative controls were largely absent, and only 25.5% of workers had access to personal protective equipment. Novel aspects of this study include shift-adjusted exposure assessment, temporal noise mapping, and an integrated evaluation of exposure, health outcomes, and governance gaps. The results highlight the urgent need for low-cost, context-appropriate interventions to mitigate noise-induced health risks in Jalingo’s small-scale sawmilling and rice-milling industries.