Effects of Exposure Duration on Potentiation of Noise Induced Hearing Loss by Carbon Monoxide

Details

• Personal Author:
  Chen GD ; Fechter LD ; Rao DB
• Description:
  Noise induced hearing loss (NIHL) is still the most common occupational disease in the U.S. Concurrent noise exposures with chemical asphyxiants such as carbon monoxide (CO) is common in work environments of firefighters, automobile mechanics and tunnel-toll booth workers. Potentiation of NIHL following acute exposure to noise (102-103 dB, broad band) and CO (1500 ppm) has been demonstrated previously. It is well known that noise exposure of varying duration is related to exposure intensities. The equal energy principle states that an increase in exposure intensity is compensated for by a corresponding decrease (halving) in exposure duration. This study investigates whether or no the NIHL resulting from combined exposures complies with the equal energy principle. Adult male Long Evans hooded rats were acutely exposed to noise alone (100dBLo 9.6-19.2 kHz), CO alone (1500 ppm), noise & CO, and air (controls). Duration of exposure varied between 2 and 4 hours. Auditory sensitivity was measured four weeks post-exposure. End points measured were electrophysiological, namely, compound action potential (CAP) an cochlear microphonic (CM). CAP is a measure of cochlear output generated at the inner hair cell-type I spiral ganglion synapse, and , CM is generated largely by the outer hair cell. These potentials were recorded in response to pure tomes between 2 and 40 kHz NIHL was found to comply with the principle of equal energy. However, hearing loss resulting from combined exposure did not follow a similar pattern. [Description provided by NIOSH]
• Subjects:
  Animals Chemistry Chemistry, Analytic Firefighters Fires Hearing Hearing Loss Hearing Loss, Noise-Induced Laboratories Noise Noise, Occupational Occupational Health Safety

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• Keywords:
  Analytical Chemistry Analytical Methods Animal Studies Automotive Emissions Chemical Analysis Dose Response Exposure Assessment Fire Fighters Fire Fighting Hearing Disorders Hearing Protection Hearing Tests Laboratory Animals Mechanics Noise Exposure Noise Induced Hearing Loss Ototoxicity Statistical Analysis Synergistic Effects Toll Booth Workers Tunnel Workers

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• ISSN:
  1096-6080
• Publisher:
  Society of Toxicology
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Oklahoma ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  48
• Issue:
  1
• NIOSHTIC Number:
  nn:20000191
• Citation:
  Toxicologist 1999 Mar; 48(1-S):292
• Contact Point Address:
  University of Oklahoma Health Sciences Center, Department of Pharmacology and Toxicology, Oklahoma City, Oklahoma 73190
• Email:
  fechter@ouhsc.edu
• CAS Registry Number:
  Carbon monoxide (CAS RN 630-08-0)
• Federal Fiscal Year:
  1999
• NORA Priority Area:
  Disease and Injury: Hearing Loss
• Performing Organization:
  University of Oklahoma, Health Sciences Center, Oklahoma Center for Toxicology, Oklahoma City, Oklahoma
• Peer Reviewed:
  False
• Start Date:
  19970901
• Source Full Name:
  The Toxicologist. Society of Toxicology 38th Annual Meeting, March 14-18, 1999, New Orleans, Louisiana
• End Date:
  20000831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0ad598c206953fac55c9273ad0ba594cc4701cd15e3f4335428b52d5acd7bb300afead7bba829276b61b49008297c34ccaf96eb10e5b62f7c8dee5d885094260
• Download URL:
  https://stacks.cdc.gov/view/cdc/198179/cdc_198179_DS1.pdf
• File Type:
  [PDF - 172.71 KB ]