ABSTRACT
{L-End}Objective To analyze the characteristics of hearing loss and the influencing factors of high-frequency hearing loss (HFHL) among noise-exposed workers in an urban rail transit enterprise over five consecutive years. {L-End}Methods A total of 1 268 noise-exposed workers, who exposed to the average noise intensity of <85.0 dB(A), in an urban rail transit enterprise was selected as the research subjects using a judgment sampling method. The pure-tone audiometry results from 2019 to 2023 were collected to analyze the result of hearing loss. The influencing factors of HFHL (average hearing threshold ≥40.0 dB at high frequencies in both ears) were analyzed using the generalized estimating equations (GEE). {L-End}Results The detection rates of threshold elevations at frequencies of 0.5-6.0 kHz increased with increasing frequency from 2019 to 2023 (all P<0.01), with the highest detection rate at 6.0 kHz. The detection rate of speech frequency hearing loss (hearing threshold weighted value≥26.0 dB in the better ear) was 0.1%, 0.0%, 0.4%, 0.2%, and 0.2%, respectively. The detection rate of HFHL from 2019 to 2023 was 2.4%, 2.8%, 2.8%, 2.1%, and 2.8%, respectively. The GEE analysis results showed that the risk of HFHL of the workers in 2022 and 2023 was lower than that in 2019 (all P<0.01), with the odds ratios and 95% confidence intervals ［OR (95%CI)］ of 0.57 (0.41-0.81) and 0.65 (0.48-0.87), respectively. The risk of HFHL was higher among vehicle maintenance worker than train drivers (P<0.05), with OR (95%CI) of 2.37 (1.18-4.77). The risk of HFHL increased with age and length of service among the workers (all P<0.05), with the OR (95%CI) of 2.05 (1.22-3.46) and 1.69 (1.12-2.54), respectively. No interaction was found between type of job and age, type of job and length of service, or age and length of service in the risk of HFHL among the research subjects(all P<0.05). {L-End}Conclusion Noise exposure below the national occupational exposure limits can lead to hearing loss in noise-exposed workers of urban rail transit enterprises, possibly affecting the hearing threshold at 6.0 kHz first. The influencing factors for HFHL in workers of rail transit are age, length of service, and type of job. There is a dose-effect relationship with age and length of service.
ABSTRACT
ObjectiveTo understand the satisfaction and comfort level of the rail transit passengers regarding hygienic environment of one city， and provide a basis of hygienic management and suggestions for rail transit operations. MethodsPassengers who have lived in the city for the past 6 months and used rail transit as their main transportation tool were selected to conduct a questionnaire survey to collect basic information， satisfaction with environmental cleanliness， perception of crowdedness， air quality and noise， etc. The Chi-square， Pearson contingency coefficient and linear trend test of orderly grouped data were used for statistical analysis. ResultsA total of 820 valid questionnaires were collected， with a total effective rate of 94.0%. Passengers' overall satisfaction with the environmental cleanliness of each link of rail transit was between basic and relatively better satisfaction， with an average of 3.52. Passengers with different one-way trip times had different satisfaction with the cleanliness of each link （P<0.05）. Passengers generally thought that the rail transit was crowded and the carriages were more crowded than the station. The level of feeling congestion was correlated with the age and gender of passengers （P<0.05）. Passengers thought that the air quality of the rail transit was inferior in carriages during the evening rush hour， and experienced different symptoms such as drowsiness， dizziness， and headache. Passengers perceived that the rail transit was noisy， and much noisier in the carriages. ConclusionPassengers are basically satisfied with the hygienic environment of rail transit. It is necessary to focus on strengthening the hygiene and cleanliness of toilets and X-ray luggage inspection systems in the future rail transit hygienic design and management. Passengers are uncomfortable with the air quality， congestion and noise in the rail transit environment. Therefore， it is necessary to strengthen the management and control of the centralized air conditioning and ventilation systems， enhance fresh air volume， reduce ambient noise， and focus on controlling the hygiene environment in the carriages in order to improve the comfort and satisfaction of passengers in the rail transit environment.
ABSTRACT
ObjectiveTo understand the satisfaction and comfort level of the rail transit passengers regarding hygienic environment of one city， and provide a basis of hygienic management and suggestions for rail transit operations. MethodsPassengers who have lived in the city for the past 6 months and used rail transit as their main transportation tool were selected to conduct a questionnaire survey to collect basic information， satisfaction with environmental cleanliness， perception of crowdedness， air quality and noise， etc. The Chi-square， Pearson contingency coefficient and linear trend test of orderly grouped data were used for statistical analysis. ResultsA total of 820 valid questionnaires were collected， with a total effective rate of 94.0%. Passengers' overall satisfaction with the environmental cleanliness of each link of rail transit was between basic and relatively better satisfaction， with an average of 3.52. Passengers with different one-way trip times had different satisfaction with the cleanliness of each link （P<0.05）. Passengers generally thought that the rail transit was crowded and the carriages were more crowded than the station. The level of feeling congestion was correlated with the age and gender of passengers （P<0.05）. Passengers thought that the air quality of the rail transit was inferior in carriages during the evening rush hour， and experienced different symptoms such as drowsiness， dizziness， and headache. Passengers perceived that the rail transit was noisy， and much noisier in the carriages. ConclusionPassengers are basically satisfied with the hygienic environment of rail transit. It is necessary to focus on strengthening the hygiene and cleanliness of toilets and X-ray luggage inspection systems in the future rail transit hygienic design and management. Passengers are uncomfortable with the air quality， congestion and noise in the rail transit environment. Therefore， it is necessary to strengthen the management and control of the centralized air conditioning and ventilation systems， enhance fresh air volume， reduce ambient noise， and focus on controlling the hygiene environment in the carriages in order to improve the comfort and satisfaction of passengers in the rail transit environment.
ABSTRACT
OBJECTIVE: To analyze the prevalence and influencing factors of multisite work-related musculoskeletal disorders(WMSDs) of workers in a railway vehicle manufacturing enterprise. METHODS: A total of 366 male workers in the assembly and riveting workshop of a railway vehicle manufacturing enterprise were selected as the research subjects using the cluster sampling method. The Chinese Musculoskeletal Questionnaire was used to investigate the prevalence of multiple sites of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors. RESULTS: The total prevalence of WMSDs was 56.3%(206/366). The prevalence of WMSDs in all parts from high to low was as follows: lower back(35.5%), hand and wrist(27.6%), neck(23.2%), shoulder(21.0%), knee(19.9%), upper back(18.6%), hip and leg(18.0%), ankle/foot(15.8%) and elbow(12.3%)(P<0.01). The total prevalence of multisite WMSDs was 38.0%(139/366). The prevalence of WMSDs in different numbers of parts from high to low was as follows: 6 or more parts(12.0%), 2 parts(10.7%), 3 parts(6.6%), 5 parts(5.5%) and 4 parts(3.3%)(P<0.01). Multiple logistic regression analysis results showed that the overweight and obese workers had higher risk of multi site WMSDs than those with normal body mass index(P<0.05).Those with long-term low heads, frequent bending, long bending of the elbows, and higher frequency of work requirements, and less frequently communicated with the leader had higher risk of multi site WMSDs(P<0.05). CONCLUSION: The prevalence of multisite WMSDs in railway vehicle manufacturing enterprise is relatively high. The influencing factors include individual factors, adverse ergonomic factors and psychosocial factors.