Styrene and Ototoxicity: Exposure Study in Volunteers

Triebig, Gerhard

Thursday, March 22, 2012: 14:15

Isla Mujeres 4 (Cancun Center)

Gerhard Triebig, Institute and Outpatient Clinic of Occupational and Social Medicine, University Hospital Heidelberg, Heidelberg, Germany

G. Triebig, Institute and Outpatient Clinic of Occupational and Social Medicine, University Hospital Heidelberg, Heidelberg, Germany

T. Bruckner, Institute and Outpatient Clinic of Occupational and Social Medicine, University Hospital Heidelberg, Heidelberg, Germany

T. Leitel, Institute and Outpatient Clinic of Occupational and Social Medicine, University Hospital Heidelberg, Heidelberg, Germany

J. Hoffmann, Institute and Outpatient Clinic of Occupational and Social Medicine, University Hospital Heidelberg, Heidelberg, Germany

S. Hoth, Department of Otorhinolaryngology, University Hospital Heidelberg, Heidelberg, Germany

Handouts

Styrene and ototoxicity 2012.pdf (264.7 kB)

Introduction
The ototoxicity of styrene in high concentrations has been demonstrated in animal studies. Up to now it is unclear, whether common exposure at the workplace can cause hearing impairment. The objective of our experimental study was to examine, if a defined styrene exposure alone or in addition with noise is associated with hearing loss.

Methods
21 healthy male volunteers (between 21 and 34 years) were exposed to styrene for six hours daily on three consecutive days each week during two consecutive weeks. In the first week the persons were exposed to styrene alone, in the second week also to industrial noise up to 85 dB(A) via earphones for three hours each day. Styrene concentrations in air of 0 ppm, 10 ppm and 50 ppm were used. Hearing loss was screened by audiometry (0.125 to 8 kHz), high frequency audiometry (9 to 16 kHz) and transitory evoked otoacoustic emissions (TEOAE).

Results
Styrene exposures were not associated with consistent changes in the audiological parameters, neither for the thresholds nor for TEOAE. Noise exposure caused a significant but reversible (by the next day) temporary threshold shift. The TEOAE parameter showed no significant differences, neither after exposure to styrene nor to noise.

Discussion
Acute exposures to maximum styrene concentrations of 50 ppm are not associated with ototoxic effects measurable with high frequency audiometry and TEOAE.

A1097 Styrene and Ototoxicity: Exposure Study in Volunteers