Home Email this page Print this page Bookmark this page Decrease font size Default font size Increase font size
Noise & Health  
 CURRENT ISSUE    PAST ISSUES    AHEAD OF PRINT    SEARCH   GET E-ALERTS    
 
 Next article
 Previous article
Table of Contents

Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Citation Manager
Access Statistics
Reader Comments
Email Alert *
Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed7118    
    Printed222    
    Emailed1    
    PDF Downloaded110    
    Comments [Add]    

Recommend this journal

 

 ARTICLES
Year : 2000  |  Volume : 3  |  Issue : 9  |  Page : 33--44

Rats exposed to toluene and noise may develop loss of auditory sensitivity due to synergistic interaction


National Institute of Occupational Health (NIOH), Copenhagen, Denmark

Correspondence Address:
Soren P Lund
National Institute of Occupational Health (NIOH),Lersř Parkallé 105, 2100 Copenhagen
Denmark
Login to access the Email id

Source of Support: None, Conflict of Interest: None


PMID: 12689441

Rights and PermissionsRights and Permissions

Hearing loss in workers exposed to organic solvents has been shown to be the effect of interaction between the exposure to solvents and noise. Synergistic interaction has been demonstrated in rats following simultaneous exposure to toluene and noise, but only at high-level toluene exposure. The present study was initiated to investigate the potential interaction of exposure to noise and toluene on the auditory system of the rat, covering a dose-range of toluene exposure (0, 500, 1000, 1500, and 2000 ppm, 6 h/d, 10 d). Exposed to toluene only, the rats exposed at the 1500 and 2000 ppm level developed a mid-frequency ABR threshold shift, whereas rats exposed to 0, 500, and 1000 ppm did not exhibit signs of auditory impairment. Rats exposed to 500 ppm toluene and noise (96 dB SPL, 2h following the daily toluene exposure, 10 d) developed a small, but statistically significant threshold shift, equal to the hearing loss in rats exposed to noise only (0 ppm). Synergistic interaction was evident at the 1000, 1500, and 2000 ppm toluene exposure levels. There was no further hearing loss at the 2000 ppm than at the 1500 ppm level, indicating that a saturation of the auditory impairment had been reached. When acute noise exposure (105 dB SPL, 4 h) followed the toluene exposure by 30 days, interaction was noted at the 1500 ppm toluene exposure level, but not at the 1000 ppm level. However, the latter type of interaction is of indirect nature and should be distinguished from the direct interaction, taking place when toluene is physically present in the cochlea during exposure to noise. Further investigations in animal models should preferentially be carried out as long-term, low-level exposure studies, showing the possible interaction at low exposure levels, where exposure to each factor alone is without any effect.






[FULL TEXT] [PDF]*


        
Print this article     Email this article