Audiometric findings in workers exposed to low levels of styrene and noise.
Audiometry and exposure measurements were conducted on workers from fiberglass and metal products manufacturing plants and a mail distribution terminal (N = 313). Workers exposed to noise and styrene had significantly worse pure-tone thresholds at 2, 3, 4, and 6 kHz when compared with noise-exposed or nonexposed workers. Age, noise exposure, and urinary mandelic acid (a biologic marker for styrene) were the variables that met the significance level criterion in the multiple logistic regression. The odds ratios for hearing loss were 1.19 for each increment of 1 year of age (95% confidence interval [CI], 1.11-1.28), 1.18 for every decibel >85 dB(A) of noise exposure (95% CI, 1.01-1.34), and 2.44 for each millimole of mandelic acid per gram of creatinine in urine (95% CI, 1.01-5.89). Our findings suggest that exposure to styrene even below recommended values had a toxic effect on the auditory system.
Morata
Thais C
TC
National Institute for Occupational Safety and Health, Division of Applied Research and Technology, Cincinnati, Ohio 45226, USA. tmorata@cdc.gov
Johnson
Ann-Christin
AC
Nylen
Per
P
Svensson
Eva B
EB
Cheng
Jun
J
Krieg
Edward F
EF
Lindblad
Ann-Cathrine
AC
Ernstgård
Lena
L
Franks
John
J
D000328:Adult; D000704:Analysis of Variance; D001299:Audiometry; D016022:Case-Control Studies; D003404:Creatinine / Q000652:urine; D005260:Female; D034381:Hearing Loss / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008333:Mandelic Acids / Q000652:urine; D008875:Middle Aged; D009623:Noise, Occupational / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D015995:Prevalence; D020058:Styrene / Q000009:adverse effects* / Q000032:analysis; D013548:Sweden / Q000453:epidemiology
D008333:Mandelic Acids; D020058:Styrene; D003404:Creatinine; C037938:mandelic acid