Determinants of early-stage hearing loss among a cohort of young workers with 16-year follow-up
- Barbara Marlenga1,
- Richard L Berg2,
- James G Linneman2,
- Douglas J Wood3,
- Steven R Kirkhorn4,
- William Pickett5,6
- 1National Farm Medicine Center, Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA
- 2Biomedical Informatics Research Center, Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA
- 3Department of Audiology, Marshfield Clinic, Marshfield, Wisconsin, USA
- 4Occupational and Industrial Medicine, Marshfield Clinic, Marshfield, Wisconsin, USA
- 5Department of Emergency Medicine, Queen's University, Kingston, Ontario, Canada
- 6Department of Community Health and Epidemiology, Queen's University, Kingston, Ontario, Canada
- Correspondence to Barbara Marlenga, National Farm Medicine Center, Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449, USA;
Contributors BM, WP and RLB conceptualised and designed this study. BM and RLB supervised the acquisition of data. DJW and SRK evaluated all hearing tests. RLB and JGL conducted all data analyses. BM, WP and RLB interpreted the data and led the writing of the manuscript. All authors reviewed drafts of the manuscript, contributed to critical revision of the manuscript and provided assistance in all other aspects of the study.
- Accepted 15 February 2012
- Published Online First 23 March 2012
Objectives The authors had a unique opportunity to study the early impacts of occupational and recreational exposures on the development of noise-induced hearing loss (NIHL) in a cohort of 392 young workers. The objectives of this study were to estimate strength of associations between occupational and recreational exposures and occurrence of early-stage NIHL and to determine the extent to which relationships between specific noise exposures and early-stage NIHL were mitigated through the use of hearing protection.
Methods Participants were young adults who agreed to participate in a follow-up of a randomised controlled trial. While the follow-up study was designed to observe long-term effects (up to 16 years) of a hearing conservation intervention for high school students, it also provided opportunity to study the potential aetiology of NIHL in this worker cohort. Study data were collected via exposure history questionnaires and clinical audiometric examinations.
Results Over the 16-year study period, the authors documented changes to hearing acuity that exceeded 15 dB at high frequencies in 42.8% of men and 27.7% of women. Analyses of risk factors for NIHL were limited to men, who comprised 68% of the cohort, and showed that risks increased in association with higher levels of the most common recreational and occupational noise sources, as well as chemical exposures with ototoxic potential. Use of hearing protection and other safety measures, although not universal and sometimes modest, appeared to offer some protection.
Conclusions Early-stage NIHL can be detected in young workers by measuring high-frequency changes in hearing acuity. Hearing conservation programmes should focus on a broader range of exposures, whether in occupational or non-occupational settings. Priority exposures include gunshots, chainsaws, power tools, smoking and potentially some chemical exposures.
- Hearing conservation
- noise-induced hearing loss
- young worker
- health and safety
- occupational health practice
- public health
Funding This study was funded by the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (R01 OH009302).
Competing interests None.
Ethics approval Ethics approval was provided by the institutional review boards of the Marshfield Clinic Research Foundation and the Faculty of Health Sciences at Queen's University.
Provenance and peer review Not commissioned; externally peer reviewed.