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Objective: To analyze the current status of work-related musculoskeletal disorders (WMSDs), work fatigue and musculoskeletal pain in Chinese occupational population, and to study the relationship between work fatigue and musculoskeletal pain and WMSDs. Methods: A total of 66 961 employees from 323 enterprises in 15 key industries in China were selected as the study subjects using stratified cluster sampling method. The incidence of WMSDs in the past year was investigated using the Chinese version of the Musculoskeletal Disorders Questionnaire, and the work fatigue and musculoskeletal pain were investigated using Borg 6-20 Rating of Perceived Exertion Scale and visual analogue scale. The data were standardized using the age composition data of 18 to 60 years from the seventh national population census. Results: The standardized annual incidence of WMSDs was higher in the front-line workers than that in the administrative and other supportive staff (38.82% vs 36.30%). The detection rates of work fatigue and musculoskeletal pain in the study subjects were 44.54% and 63.08%, respectively. The result of S-curve fitting showed that the risk of WMSDs increased with the level of work fatigue (P<0.01). Among the front-line workers, the average of monthly fatigue frequency in the neck, shoulder, lower back, upper back, wrist/hand, foot and ankle, knee, leg, and elbow were higher in the group with WMSDs compared to those without WMSDs (all P<0.01). The pain degree of musculoskeletal pain was higher in all nine sites in the fatigued group than in the no-fatigue group (all P<0.01). The standardized detection rate of musculoskeletal pain was higher in the fatigued group than in the non-fatigued group (80.38% vs 25.71%). The work fatigue was moderate and positively correlated with musculoskeletal pain in all seven sites except the lower back and elbow, with Kendall Tau-b correlation coefficients ranging from 0.423 to 0.546 (all P<0.01). Conclusion: There is a good correlation between work fatigue and local musculoskeletal pain, work fatigue and WMSDs in Chinese occupational population. Implementing ergonomic interventions to control the development of work fatigue can be an effective measure for preventing WMSDs.
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{L-End}Objective To investigate the current status and influencing factors of leg work-related musculoskeletal disorders (WMSDs) in shipbuilding workers. {L-End}Methods A total of 3 393 shipbuilding workers from Guangdong Province, Liaoning Province, Shandong Province, and Beijing City were selected as the research subjects using the convenience sampling method. The Chinese Version of the Musculoskeletal Disorders Questionnaire was used to investigate the prevalence of leg WMSDs in the past year. A multivariate logistic regression model was used to analyze the influencing factors of leg WMSDs. {L-End}Results The prevalence of leg WMSDs in the research subjects was 11.3% (382/3 393). The result of multivariate logistic regression showed that the risk of leg WMSDs was higher in workers with a length of service >10 years than those with a length of service <5 years (P<0.05). Workers with frequent used of vibration tools at work had higher the risk of leg WMSDs (all P<0.05). Workers who did the same work every day, had insufficient rest time, had a shortage of department staff, and those who often repeated the same leg movements had a higher risk of leg WMSDs (all P<0.05). The risk of leg WMSDs in workers who sometimes stand for a long time was lower than that in workers who rarely stand for a long time (P<0.01). {L-End}Conclusion Length of service, rarely long-standing work, use of vibration tools at work, daily engagement in the same work, in-adequate rest time, shortage of department staff, and frequent repetition of the same leg movements are all influencing factors for leg WMSDs in shipbuilding workers.
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Background Prolonged awkward postures during occupational activities can lead to excessive musculoskeletal load on the wrist of workers and symptoms such as wrist pain or discomfort. Objective To survey the prevalence of wrist pain among workers in 10 key industries and analyze its correlation with wrist working postures. Methods By using stratified cluster sampling method, workers from 10 key industries, such as footwear manufacturing industry, shipbuilding manufacturing industry, and automobile manufacturing industry, were selected from seven regions in North China, East China, Central China, South China, Southwest China, Northwest China, and Northeast China. The demographic information, wrist working postures, pain in wrist of the workers were collected through a cross-sectional survey. Pearson χ2 test was used to compare prevalence by selected factors, trend χ2 test for between group comparison, and unconditional logistic regression models for the association of wrist working postures with wrist pain. Results There were 64052 workers enrolled in this survey, and 56286 provided valid questionnaires (the effective rate was 87.8%). According to the survey, the prevalence of wrist pain was 23.3% (13112/56286), and the industries with higher prevalences were footwear manufacturing (27.1%, 1927/7106), automobile manufacturing (24.9%, 5378/21560), and shipbuilding and related equipment manufacturing (24.4%, 850/3488) industries. Finger pinching (OR=2.09, 95%CI: 1.95-2.24), frequent wrist bending (OR=2.03, 95%CI: 1.92-2.15), fixed wrist bending (OR=1.77, 95%CI: 1.69-1.85), wrist on hard edge (OR=1.34, 95%CI: 1.28-1.40), and arms over shoulders (OR=1.11, 95%CI: 1.05-1.17) increased the risk of reporting wrist pain. Conclusion Awkward postures are related to wrist pain among workers in selected 10 key industries. The related factors are wrist on hard edge, frequent wrist bending, finger pinching, fixed wrist bending, and arms over shoulders.
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Objective@#To investigate the prevalence and risk factors of occupational musculoskeletal disorders among workers in heavy-duty automobile parts factories in Beijing Municipality, so as to provide insights into development of effective interventions for occupational musculoskeletal disorders.@*Methods@#The workers in three heavy-duty automobile truck parts factories in Beijing Municipality were recruited using the convenient sampling method during the period from May 2019 to October 2020. Subjects' demographic characteristics, type of job and prevalence of occupational musculoskeletal disorders at various sites were collected using self-designed electronic questionnaires, and the factors affecting the development of occupational musculoskeletal disorders were identified using a multivariable logistic regression model.@*Results@#A total of 264 workers were enrolled, including 260 males (98.48%) and 4 females (1.52%). The participants had a mean age of (31.71±6.13) years, and mean duration of (7.51±5.25) years at current position, and mechanical technician was the major type of work (129 workers, 48.86%). The prevalence of occupational musculoskeletal disorders was 70.08% among the participants, and high prevalence of occupational musculoskeletal disorders was found in the lower back/waist (41.28%), shoulder (40.15%), neck (39.02%) and upper back (33.33%). Multivariable logistic regression analysis identified females (OR=1.280, 95%CI: 1.021-1.602) and head-down posture at work (OR=2.644, 95%CI: 1.034-6.763) as risk factors for occupational musculoskeletal disorders at neck; females (OR=1.633, 95%CI: 1.624-2.117), sheet metal workers, mechanical technicians and painters (OR: 5.811-10.452, 95%CI: 1.205-54.027), working in an uncomfortable posture (OR：1.376-7.749, 95%CI: 1.034-27.270) and frequent working overtime (OR=2.081, 95%CI: 1.192-4.137) as risk factors for occupational musculoskeletal disorders at shoulder; and sheet metal workers, mechanical technicians and painters (OR: 8.760-11.948, 95%CI: 1.630-66.927), working in an uncomfortable posture (OR：4.067-12.185, 95%CI: 1.332-47.523) and frequent working overtime (OR=2.201, 95%CI: 1.142-4.244) as risk factors for occupational musculoskeletal disorders at waist/back.@*Conclusions@#The prevalence of occupational musculoskeletal disorders is high among workers in heavy-duty automobile parts factories, which mainly occur at shoulder, neck, waist and back. Type of work, working posture and working duration are main factors affecting the development of occupational musculoskeletal disorders.
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With the improvement of living standards in China, people pay more and more attention to sports and fitness. Therefore, the contradiction between air pollution and sports becomes an urgent problem to be solved. In this paper, the acute and chronic effects of exercise on human cardiovascular and pulmonary functions under the environment of particulate matter pollution are summarized and analyzed, and countermeasures are put forward on the basis of this analysis.
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Objective@#To evaluate the pathogenicity of Acinetobacter venetum（Av），which is expected to be used as an environmental remediation agent，using Caenorhabditis elegans（C.elegans）. @*Methods@#The C.elegans were cultured on the media loaded with E.coli OP50 and Av，respectively. The pathogenicity of Av was evaluated by observing the effects of Av on the growth，movement，digestive function，lifespan and reproduction of C.elegans，compared with that of another evaluation system according to NY 1109-2017 General Biosafety Standard for Microbial Fertilizers.@*Results@#By C. elegans system，it was found that the body length，width，head thrash frequency，body bending frequency and average lifespan [（13.5±0.4）d vs.（13.7±0.4）d] of adult nematodes in the Av group were not significantly different from those in the OP50 group（all P>0.05）；while the average time of defecation cycle in the Av group shortened，the total number of progenies in the Av group increased by 18.7%（all P<0.05）. According to NY1109-2017 General Biosafety Standard for Microbial Fertilizers，it was found that the oral LD50 values for both male and female mice were more than 10 g/kgbw，which was practically non-toxic；the pathogenicity test of acute intraperitoneal injection showed that the animals did not have signs of poisoning，deaths or any abnormalities in gross anatomy；Av had no irritation to damaged skin and eyes of rabbits；the hemolysis test was negative；Av was sensitive to seven antibiotics and was medium to one antibiotic. @*Conclusion@#Av is not pathogenic. C. elegans can be used in early screening for the pathogenicity of environmental remediation agents.
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The influencing factors of ultrasonic extraction(UE) and ultrasonic-soxhlet extraction(USE) were analyzed based on orthogonal experimental design. The optimum analytical conditions of two methods were determined. The three different methods: UE, USE and traditional soxhlet extraction(SE) were compared by simultaneous analysis with three different soil samples: fresh contaminated soil, soil after microbial remediation and soil after phytoremediation. The optimum condition of the UE was extracting 4 times with chloroform, 15 mL extractant every time. The optimum condition of the USE method was ultrasonic for 10 min at 60 W, followed by soxhlet extraction with 125 mL extractant for 6 h. Compared the three different methods, USE method showed the best result with the highest average extraction rate of 102.98%, the UE method with average extraction rate of 99.69%, and the SE method with low average extraction rate of 97.31%. The research indicates that USE method is effective in determining soil total petroleum hydrocarbons(TPH) within shorter time and higher efficiency and can be used as a method for determining TPH content in different soils.