环境与职业医学 (Apr 2022)
Noise-induced hearing loss associated with non-Gaussian noise in manufacturing industry of China: A systematic review and meta-analysis
Abstract
BackgroundNon-Gaussian noise has become the dominant noise type in industry. However, the epidemiological characteristics of non-Gaussian noise exposure and associated noise-induced hearing loss (NIHL) are still unclear.ObjectiveTo summarize the epidemiological characteristics of NIHL associated with non-Gaussian noise in manufacturing industry in China and provide a basis for the early prevention and control of occupational hearing loss.MethodsChinese and English literature on hearing loss associated with non-Gaussian noise in China were retrieved. The overall prevalence was calculated based on the prevalence data provided by each included study. A meta-analysis of studies with Gaussian noise as a control group was also performed and the overall weighted odds ratio (OR) was calculated to compare the effects of non-Gaussian noise and Gaussian noise on hearing loss. Publication bias was evaluated by funnel plot and Egger regression, and a sensitivity analysis was performed by eliminating references in turn.ResultsA total of 37 cross-sectional studies involving 25 055 Chinese manufacturing workers exposed to non-Gaussian noise were included, 92.5% of whom were male. These workers aged (32.7±9.6) years were exposed to non-Gaussian noise at (87.0±4.2) dB(A) for (6.8±4.9) years. The mean cumulative noise exposure (CNE) was (95.9±8.0) dB(A)·year. The prevalence rate of high-frequency NIHL (HFNIHL) and speech-frequency NIHL (SFNIHL) were 29.0% and 14.2%, respectively. The results of the meta-analysis treating 19 cross-sectional studies with Gaussian noise as a control group showed that there were no significant differences in age, exposure duration, and equivalent continuous A-weighted sound pressure level (LAeq), and CNE between the non-Gaussian noise group and the Gaussian noise group. The overall weighted OR of HFNIHL was 1.87 (95%CI: 1.46−2.41), which was statistically significant. The funnel plot showed good symmetry and the result of Egger regression was t=−0.11, P=0.910 (>0.05), suggesting a low risk of publication bias in this meta-analysis. The sensitivity analysis showed no significant changes of results after eliminating references in turn, indicating that the results were robust.ConclusionChinese manufacturing workers, mainly young adult males, are exposed to non-Gaussian noise at high levels for a long time and have a high prevalence of NIHL. Compared to workers exposed to Gaussian noise, those exposed to non-Gaussian noise suffer from more serious hearing loss.
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