Occupational Noise Exposure and Hearing Conservation Program Effectiveness in a Steel Rolling Mill in Kogi State

Occupational noise-induced hearing loss (NIHL) is a prevalent and preventable occupational disease in heavy industries globally. This study assessed noise exposure levels and evaluated the effectiveness of the hearing conservation program (HCP) in a steel rolling mill in Ajaokuta, Kogi State, North Central Nigeria. Personal noise dosimetry measurements were conducted on 120 workers across six production departments during three consecutive work shifts. Audiometric testing was performed on all participating workers, and HCP documentation including audiometric records, noise control interventions, and training records were reviewed and evaluated against OSHA and NESREA occupational noise standards. Results showed that workers in the rolling, cutting, and furnace departments consistently experienced noise levels exceeding 95 dB(A) as an eight-hour time-weighted average. Audiometric data revealed noise-induced threshold shifts in forty-seven percent of workers, with workers employed for more than eight years demonstrating significantly greater hearing loss. HCP documentation review showed irregular audiometric testing intervals and inadequate follow-up for workers exhibiting threshold shifts. Hearing protection device provision was universal, but device selection was not matched to measured exposure levels in forty-two percent of cases. The study concludes that the HCP at the facility requires substantial upgrading. Recommendations include noise source engineering controls, HCP component strengthening, regular qualified audiometric testing, and mandatory remedial action protocols for workers with progressive hearing loss. Keywords: occupational noise, hearing conservation, steel mill, Kogi State, audiometry.