The aim of this study was to determine the effect of lead, cadmium, arsenic, toluene, and xylene exposure on hearing compared with noise exposures alone.
Personnel at a shipyard (n = 1266) were divided into four exposure groups on the basis of concentrations: low metals/low solvents/high noise (reference group), high metals/high solvents/low noise, high metals/low solvents/high noise, and high metals/high solvents/high noise. Hearing changes occurring from the years 2004 to 2015 were analyzed.
Hearing changes were significantly worse at 1000 Hz (P = 0.007), averaged across 2000 to 4000 Hz (P = 0.014), and averaged across 500 to 6000 Hz (P = 0.014) for the high metals/high solvent/high noise group compared with the low metals/low solvents/high noise only reference group.
Simultaneous exposures classified as high for metals/solvents/noise appear to damage hearing more than exposure to noise alone. Hearing conservation programs should take into consideration combined exposures to metals, solvents, and noise, not simply exposure to noise.
Uniformed Services University, Preventive Medicine and Biostatistics Department, Bethesda, Maryland (Dr Schaal); Indiana University of Pennsylvania, Safety Sciences Department, Indiana, Pennsylvania (Drs Schaal, Slagley, Zreiqat, Paschold); Department of the Air Force, Air Force Institute of Technology, Department of Systems Engineering and Management, Wright-Patterson AFB, Ohio (Dr Slagley); and Indiana University of Pennsylvania, Communication Disorders, Special Education, and Disability Services, Indiana, Pennsylvania (Dr Richburg).
Address correspondence to: Nicholas Cody Schaal, PhD, Uniformed Services University of the Health Sciences, Preventive Medicine and Biostatistics Department, 4301 Jones Bridge Road, Bethesda, MD 20814 (email@example.com).
All authors participated in study design, analysis, and interpretation of the data. All authors approved the final version to be published and agreed to be accountable for all aspects of the work and ensuring questions related to the accuracy of any part of the work are appropriately investigated and resolved.
The authors report that there was no funding source for the work that resulted in the article or the preparation of the article.
Portions of this research were presented at the following:
(1) San Diego American Industrial Hygiene Association Professional Development Symposium, San Diego, CA, September 2017
(2) American Industrial Hygiene Conference and Exposition, Seattle, WA, June 2017.
(3) Air Force Institute of Technology Occupational & Environmental Health Seminar, Dayton OH, April 2017.
The U.S. Navy's Naval Medical Center San Diego Department of Clinical Investigation Institutional Review Board (IRB) exempted the study from IRB review under protocol number NHBR.2015.0029. In addition, Indiana University of Pennsylvania's IRB for Protection of Human Subjects approved the research project and exempted the project from continuing review under IRB Protocol number 15-183. Informed consent was not sought since personnel data for the study were retrieved from a database of historical records. In addition, personally identifiable information for each record was de-identified.
The contents of this publication are the sole responsibility of the authors and do not necessarily reflect the views, opinions, or policies of Uniformed Services University (USU), the Department of Defense (DoD), or the Department of the Navy or Air Force. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Government.
The authors report no conflicts of interest.