PURPOSE: To get to know the effects of the combined exposure to carbon monoxide and noise on hearing, in a group of forklift operators. METHODS: A pure tone audiometry was carried out in a control group exposed only to noise (Group 1), and a group of employees exposed to both carbon monoxide and noise (Group 2). RESULTS: A single case of noise-induced hearing loss was observed in the group exposed to noise (Group 1), and five cases were observed in the group exposed to both carbon monoxide and noise (Group 2). The occurrence of significant threshold change was also higher in Group 2. There was a difference between the auditory thresholds in 1 and 8 kHz of the left ear in Group 2, when compared to Group 1. CONCLUSION: Results showed significant auditory effects caused by the combined exposure of forklift operators to carbon monoxide and noise, when compared to the group exposed only to noise. Thus, environmental, biological, and auditory monitoring of forklift operators is indispensable, regardless the level of noise to which they are exposed.
Noise effects; Hearing loss/etiology; Chemical compounds/adverse effects; Occupational exposure; Health occupational