The combined effect of cigarette smoking and occupational noise exposure on hearing loss: evidence from the Dongfeng-Tongji Cohort Study

Dongming Wang,Jing Yuan,Wenzhen Li,Kun Zhang,Weihong Chen,Zhichao Wang,Tao Zhou,Yue Zhan,Meian He,Weijia Kong,Huan Guo,Xiaomin Zhang,Min Zhou

doi:10.1038/s41598-017-11556-8

Abstract

Combined effect of cigarette smoking and occupational noise exposure on hearing loss has rarely been evaluated among Chinese population, especially among females. This cross-sectional study was conducted in 11196 participants of Dongfeng-Tongji cohort study. Smoking status was self-reported through questionnaire and occupational noise exposure was evaluated through workplace noise level and/or the job titles. Hearing loss was defined as a pure-tone mean of 25 dB or higher at 0.5, 1, 2, and 4 kHz in both ears. Compared with participants without occupational noise exposure, the risk of hearing loss was significantly higher for noise exposure duration ≥20 (OR = 1.45, 95%CI = 1.28–1.65). The association was particularly evident among individuals who were males (OR = 1.74, 95%CI = 1.45–2.08) and aged ≥ 70 (OR = 1.74, 95%CI = 1.30–2.33). Similarly, the risks increased with the increasing of pack-years in males and all age groups except for those aged <60. As to the combined effect, the hearing loss risk was highest for noise exposure duration ≥20 and pack-years ≥25 (OR = 2.41, 95%CI = 1.78–3.28), especially among males (OR = 2.42, 95%CI = 1.74–3.37) and those aged ≥70 (OR = 2.76, 95%CI = 1.36–5.60). Smoking may be an independent risk factor for hearing loss. And it may synergistically affect hearing when combined with occupational noise exposure, especially among males and older participants.

Highlights

Occupational noise is considered one of the most pervasive occupational hazards around the world[1]
We explored the independent and combined dose-response association of occupational noise exposure and smoking with hearing loss
High risks of hearing loss were observed among participants long-term exposed to occupational noise and/or took more pack-years of smoking, even controlling for other confounders

Summary

Introduction

Occupational noise is considered one of the most pervasive occupational hazards around the world[1]. In Europe, it is reported that almost 28% of workers work in occupational settings with noise levels between 85 and 90 A-weighted decibels (dBA)[4]. It may be more serious in China owing to its larger occupational population[5]. The combined effect involving smoking and occupational noise exposure on hearing loss is noticeable due to the high prevalence of smoking among occupational workers in China[26]. We conducted a cross-sectional study to examine the independent and combined effects of smoking and occupational noise exposure on hearing loss in a large middle-aged and older Chinese population, especially to explore the association among female participants

Methods

Results

Conclusion