Auditory dysfunction associated with solvent exposure

Abstract

BackgroundA number of studies have demonstrated that solvents may induce auditory dysfunction. However, there is still little knowledge regarding the main signs and symptoms of solvent-induced hearing loss (SIHL). The aim of this research was to investigate the association between solvent exposure and adverse effects on peripheral and central auditory functioning with a comprehensive audiological test battery.MethodsSeventy-two solvent-exposed workers and 72 non-exposed workers were selected to participate in the study. The test battery comprised pure-tone audiometry (PTA), transient evoked otoacoustic emissions (TEOAE), Random Gap Detection (RGD) and Hearing-in-Noise test (HINT).ResultsSolvent-exposed subjects presented with poorer mean test results than non-exposed subjects. A bivariate and multivariate linear regression model analysis was performed. One model for each auditory outcome (PTA, TEOAE, RGD and HINT) was independently constructed. For all of the models solvent exposure was significantly associated with the auditory outcome. Age also appeared significantly associated with some auditory outcomes.ConclusionsThis study provides further evidence of the possible adverse effect of solvents on the peripheral and central auditory functioning. A discussion of these effects and the utility of selected hearing tests to assess SIHL is addressed.

Perda auditiva associada à exposição ocupacional a solventes orgânicos: uma revisão sistemática

“…In all studies of possible impairment to CANS and listening skills, the results suggested action of solvents on the central auditory pathways, indicating that PTA might not be the only recommended audiological test for this population 17,34,36,37,39 .…”

“…The authors suggest the possibility that the data were underestimated, since the methods used may have failed to detect auditory disorders due to their locations in the auditory system. Workers exposed to combined "noise and solvent mixture," when compared with non-exposed controls, had worse results in CAP tests: Speechin-Silence (SS), PPS 36 , HINT 36,39 , Random Gap Detection (RGD) 36,37,39 and DD 34,36 , but no statistically significant difference was observed for MLD 36 . The results suggest that solvents may be adversely associated with central auditory dysfunction.…”

“…Shifts in audiometric thresholds and increased prevalence and/or probability of OHL were some of the data found among the groups of co-exposure to noise and solvent mixture 17,30,[32][33][34][35][36][37]39 .…”

Occupational Chemical-Induced Hearing Loss

“…Fuente et al (2008) also showed that in a group of 100 workers exposed to a mixture of solvents and 100 non-exposed workers, solvents were significantly associated with poorer pure-tone thresholds, lower amplitudes of transient evoked otoacoustic emissions (TEOAEs), and poorer results for central auditory functioning tests. Recently, in a study investigating a group of 30 medical laboratory workers exposed to xylene and a control group of non-exposed workers, Fuente (2010) found significant differences between groups for ABR results. Xylene-exposed workers presented with longer ABR latencies than nonexposed workers.…”

“…1. Summary of audiological findings in solvent-exposed subjects from Fuente 2008Fuente , 2010 and Fuente et al studies (2006Fuente et al studies ( , 2007Fuente et al studies ( , 2009Fuente et al studies ( , 2011.…”