Objective To evaluate the role of distortion product otoacoustic emissions (DPOAE) testing in evaluating early hearing loss among noise-exposed workers. Methods A total of 174 noise-exposed workers in a metal shipbuilding enterprise were selected as the research subjects by the convenience sampling method. Pure tone audiometry (PTA), DPOAE and the level of noise exposure were conducted on the workers. The rank correlation analysis was used to analyze the correlation between DPOAE amplitude and PTA threshold. The multilevel model was used to analyze the effects of gender, age, noise exposure intensity, cumulative noise exposure (CNE), hearing loss classification and PTA threshold on DPOAE results. Results At the frequencies of 0.50, 1.00, 2.00, 3.00, 4.00, 6.00 and 8.00 kHz, the DPOAE amplitude was negatively correlated with the PTA threshold (rank correlation coefficients were -0.12, -0.48, -0.47, -0.18, -0.23, -0.44, -0.19, respectively, all P<0.01). At the most frequencies, DPOAE amplitude was negatively correlated with age and CNE (all P<0.05). The results of multilevel model analysis showed that there were significant differences in DPOAE amplitudes at certain frequencies across gender, age, noise intensity, CNE, and hearing loss classification (all P<0.05). Significant differences in DPOAE responses were found among different CNE and hearing loss groups (all P<0.01). Conclusion DPOAE testing can objectively reflect the hearing status of noise-exposed workers and could be considered for inclusion in routine hearing monitoring to facilitate early detection of noise-induced hearing loss.

OBJECTIVE: To determine the prevalence and influencing factors of work-related musculoskeletal disorders(WMSDs) among workers in a shipyard. METHODS: A total of 496 workers in a large shipyard in Guangdong Province were selected as research subjects using the convenient sampling method. The Questionnaire of Musculoskeletal Disorders was used to investigate the prevalence of WMSDs in various regions of the body in the past year.Multivariate logistic regression was used to analyze the potential influencing factors of WMSDs in the frequently affected body parts. RESULTS: The prevalence of WMSDs was 70.2%(348/496). The prevalence rates of WMSDs in different body regions were: lower back/waist(43.1%), neck(29.4%), shoulder(29.0%), hand/wrist(25.4%), knee(22.4%), hip/leg(14.3%), ankle/foot(12.1%), upper back(11.3%) and elbow(9.3%). Multivariate logistic regression analysis results showed that increased risk of lower back/waist WMSDs occurred in workers who carry heavy objects>5.0 kg, who work in uncomfortable positions, who repeatedly perform the same work every day, and who repeatedly perform the same action using the lower limbs and ankles(P<0.05). Employees working ≤8 hours or more than 8 hours per day had higher risk of developing lower back/waist WMSDs compared with workers working 8-10 hours per day(P<0.05). CONCLUSION: The prevalence of WMSDs among workers in the shipyard is high.The lower back/waist WMSD is the most common one. The influencing factors include work organization and adverse ergonomic factors.