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APHA Scientific Session and Event Listing

Curtis E. Cummings, MD, MPH¹, Zekarias Berhane, PhD², Robert T. Sataloff, MD, DMA³, and Joseph Sataloff, MD DSc³. (1) Department of Environmental and Occupational Health, Drexel University School of Public Health, Mail Stop 660, 245 North 15th Street, Philadelphia, PA 19102-1192, 215-762-3938, cc383@drexel.edu, (2) Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Mail Stop 660, 245 North 15th Street, Philadelphia, PA 19102-1192, (3) Department of Otolaryngology, Jefferson Medical College, Thomas Jefferson University, 1721 Pine Street, Philadelphia, PA 19103

Background. Noise-induced hearing loss remains a significant hazard. We performed a prospective cohort study, including otologic evaluations, of railroad workers exposed to continuous noise while working inside a railway tunnel. No previous studies were found of hearing loss in railway maintenance workers.

Methods. Full-shift personal noise dosimetry was performed for 6 workers. Nine workers underwent otologic evaluations, with medical and exposure questionnaires, and audiograms, at baseline and follow-up, 24 to 55 months later (mean 37.6 months).

Results. Mean noise level was 94.8 dBA (8-hour TWA, range 92 to 98 dBA). Of the 9 workers, 3 developed a recordable standard threshold shift (STS) in 1 or both ears. Mean and median thresholds increased from baseline to follow-up for all frequencies in each ear, except at 500 hertz (Hz), left ears, and 6000 Hz, right ears. Mean threshold at 2000, 3000 and 4000 Hz (the recordable range) increased from baseline to follow-up for both ears, for each subject's right ear, and for 7 of 9 subjects' left ears. There were statistically significant increases in mean thresholds at 2000, 3000 and 4000 Hz for left ears, right ears, and both ears combined.

Conclusions. In a cohort of 9 rail workers, we found a significant increase in mean hearing thresholds, after a relatively brief follow-up time. Analysis of hearing loss data should report mean thresholds in addition to numbers of cases of recordable hearing loss. Small cohorts can yield results that are statistically and clinically significant.

Learning Objectives:

• Describe the development of noise-induced hearing loss in railway workers
• Correlate noise-exposure meaurement with hearing loss outcomes
• Discuss the evaulation of groups with exposure to occupational noise
• Explain advantages of evaluation of mean hearing thresholds in worker groups

Keywords: Occupational Surveillance, Workplace Stressors

Presenting author's disclosure statement:

Not Answered