Hearing Conservation in a Meat Processing Facility

Introduction: The aim of this study was to evaluate personal noise exposures at a meat processing facility, and educate employees on the proper use of hearing protectors. Materials and Methods: We collected full-shift personal dosimetry on thirty-six production floor employees, one quality control employee, and four maintenance employees. These were compared to the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) criteria. We also collected point source noise measurement at eight workstations from precook. We administered a questionnaire to assess production floor employees’ hearing loss perception and non-occupational source of noise exposure. We also documented how employees inserted the earplug provided by the facility (Moldex SparkPlugs) following the required three steps of inserting an earplug: (1) roll the earplug; (2) pull the ear with opposite hand across the head; (3) insert the earplug. We provided employees with two earplugs (3M Ultra Fit, and E-A-R Classic) to evaluate their preference. We used Fisher exact test to evaluate the association between employees’ questionnaire response and the way they insert earplugs, and employees’ questionnaire response and their earplug preference. Results: Thirty-three (80.48%) of the measured personal noise level exceeded the NIOSH Recommended Exposure Limit, twenty-nine (70.73%) of these exceeded the OSHA Action Level and nine (21.95%) exceeded the OSHA Permissible Exposure Limit. The point source noise levels ranged from 81.5 dBA to 97.5 dBA using an A-weighted scale (dBA). Maximum measured sound level was 97.5 dBA and 96.1 (dBC). Loudest noise levels occurred between 2500 Hertz (Hz) – 4000 Hz at four workstations. Eight (12.90%) employees inserted earplugs correctly. Forty-two (56.76%) preferred the 3M Ultra Fit earplug over other types. Twelve (16.44%) reported they experience ringing in the ear, and of these eight reported improvements in the ear over time. Most of the employees did not report difficulty in hearing. There was a significant association (p-value 0.02) between employees’ use of hearing protection device (HPD) outside of work around loud noise and the way they inserted earplugs. Employees who used HPD outside of work around loud noise inserted earplug correctly as compared to those who did not use HPD outside of work around loud noise. There was no significant relationship between employees’ questionnaire response and their earplug preference. Conclusion: Production floor employees and maintenance employees are exposed to excessive loud noise level, and they are at risk of developing noise-induced hearing loss (NIHL). Employees that work over full shift at workstations with the loudest exposure between 2500 Hz -4000 Hz are at risk of NIHL development. Implementation of engineering control may reduce loudest noise exposure that occurred at 2500 Hz - 4000 Hz. Adequate training on the proper use of earplugs, and provision of varieties of earplug may increase employees’ compliance with the proper use of hearing protectors