Ethyl benzene should be considered ototoxic at occupationally relevant exposure concentrations.
Publication: Toxicology and industrial health
Publication Date: 2008
Study Author(s): Vyskocil, A;Leroux, T;Truchon, G;Lemay, F;Gendron, M;Gagnon, F;El Majidi, N;Viau, C;
Institution: Département de santé environnementale et santé au travail, Université de Montréal, Montréal, Québec, Canada. firstname.lastname@example.org
Shortcut link to this study: http://science.naturalnews.com/pubmed/19022877.html
Organic solvents can produce Ototoxic
effects in both man and experimental animals. The objective of this study was to review the literature on the effects of low-level exposure to ethyl benzene on the auditory system and consider its relevance for the occupational settings. Both human and animal investigations were evaluated only for realistic exposure concentrations based on the permissible exposure limits. In Quebec, the Time-Weighed Average Exposure Value for 8A h (TWAEV) is 100A ppm (434A mg/m(3)) and the Short-Term Exposure Value for 15A min (STEV) is 125A ppm (543A mg/m(3)). In humans, the upper limit for considering ototoxicity data relevant to the occupational exposure situation was set at STEV. Animal data were evaluated only for exposure concentrations up to 100 times the TWAEV. In workers, there is no evidence of either ethyl benzene-induced hearing losses or ototoxic interaction after combined exposure to ethyl benzene and noise. In rats, ethyl benzene affects the auditory function mainly in the cochlear mid-frequency range and ototoxic interaction was observed after combined exposure to noise and ethyl benzene. Further studies with sufficient data on the ethyl benzene exposure of workers are necessary to make a definitive conclusion. Given the current evidence from animal studies, we recommend considering ethyl benzene as an ototoxic agent.