Hearing risk in motorcycle taxi drivers of a Southern Brazilian city

ABSTRACT Objective: to characterize the hearing profile of motorcycle taxi drivers and analyze the risk of their exposure to noise. Methods: a cross-sectional study with 17 motorcycle taxi drivers of a city on the Southern coast of Brazil, in 2008. Noise was measured at workplace and during a standard route. The dose of exposure to noise was calculated, a questionnaire on the perception of auditory and extra-auditory effects was applied and an auditory hearing assessment through threshold tonal audiometry was performed. Results: at workplace, noise was around 73dBA (decibels, A scale), and while commuting, noise was above 100% for a 12-hour working day. Strain and stress/fatigue after work were reported by 58.8% of the subjects and 52.9% of them showed hearing losses, five presenting characteristic noise-induced hearing losses (NIHL). However, the motorcycle taxi drivers did not associate the adverse health effects to the continuous exposure to noise. Conclusion: the motorcycle taxi drivers presented hearing risk, 29% of them presenting hearing alterations with characteristics suggestive of noise-induced hearing loss, which makes the implementation of auditory conservation programs of extremely importance for this class of workers.

摘要
研究目的：明确摩托车出租车驾驶员的听力特征，并分析其噪声暴露风险。
方法：2008年，针对巴西南部沿海某城市的17名摩托车出租车驾驶员开展横断面研究。在其工作场所及标准运营路线上开展噪声监测，计算噪声暴露剂量；实施听觉及听觉外效应感知问卷调查，并通过纯音听阈测试完成听力阈值评估。
结果：工作场所噪声约为73分贝A计权（dBA）；按12小时工作日计算，运营通勤过程中的噪声暴露量超过100%。58.8%的受试者报告工作后存在躯体劳损、应激与疲劳症状；52.9%的受试者存在听力损失，其中5例表现出典型的噪声性听力损失（noise-induced hearing loss, NIHL）。但该群体未将上述不良健康效应与持续噪声暴露建立关联。
结论：摩托车出租车驾驶员存在听力损伤风险，29%的受试者出现疑似噪声性听力损失的听力改变，因此为该类劳动者制定听力保护方案具有极高的必要性。