Carbon monoxide exposure potentiates high-frequency auditory threshold shifts induced by noise

Chemical exposure and hearing loss

“…111 Both carbon monoxide and cyanides have been found to potentiate permanent noise-induced hearing loss in animals and humans. 106,[112][113][114][115][116][117][118] This potentiation may be the result of a reduction in the cell's ability to repair noise-induced damage due to carbon monoxide poisoning. 112,113 What do epidemiological studies show?-In a large epidemiological investigation conducted by Lacerda et al, 118 the hearing thresholds of employees working in noisy occupational environments with combined carbon monoxide exposures were compared with the hearing thresholds of employees working in noisy occupational environments without carbon monoxide.…”

Effects of occupational exposure to organic solvents and noise on hearing.

“…Occupation al hearing loss has long been reco gnized as a direct health effect of overexpo sur e to nois e, but only recently has expo sure to solv ent s been con sidered as a contributor to the development of hearing impairment (4)(5)(6)(7)(8)(9)(10). There is evidence wh ich suggests that noise interact' > synerg istica lly with various drugs and chemicals (11)(12)(13)(14)(15)(16)(17)(18). Evidence is also beginning to accumulate which suggests that an ototra umatic interaction may ex ist between noise and org an ic sol-ve nts.…”

Health hazard evaluation report: HETA-2000-0110-2849, Human Performance International, Inc., Charlotte, North Carolina.

“…76,77 In those studies, broad band noise exposure alone and CO exposure alone did not produce a permanent auditory threshold shift, but there was significant auditory impairment when CO was presented simultaneously with noise.…”