Influencing factors of work-related musculoskeletal disorders among civil aviation flight attendants / 中国职业医学

OBJECTIVE: To analyze the prevalence and influencing factors of work-related musculoskeletal disorders(WMSDs) in civil aviation flight attendants. METHODS: A total of 810 flight attendants from three civil aviation airlines in China were selected as research subjects using the convenient sampling method. The revised Musculoskeletal Disorders Investigating Questionnaire was used to investigate the prevalence of WMSDs in various parts of the body in the past year. RESULTS: The total prevalence of WMSDs in flight attendants in this survey was 64.4%(522/810). The prevalence of WMSDs in various parts of the body from high to low was: neck(48.0%), shoulder(38.6%), lower back/waist(26.0%), upper back(19.8%), feet(15.1%), knee(14.0%), hip and leg(11.0%), hand and wrist(9.0%) and elbow(5.1%). The results of multivariate logistic regression analysis showed that working with an uncomfortable posture and the shortage of staff in the work sector were risk factors for neck WMSDs(all P<0.05). The protective factors were sufficient rest time and voluntary decision when to take a break during work(all P<0.05). Carrying heavy objects >20 kg, working in uncomfortable posture and shortage of staff were risk factors for shoulder WMSDs(all P<0.05). Working in uncomfortable posture and repeated an operation every minute were risk factors for lower back/waist WMSDs(all P<0.05), and sufficient rest time was its protective factor(P<0.05). CONCLUSION: The prevalence of WMSDs in civil aviation flight attendants is high, and the neck, shoulder and ower back/waist are the most commonly affected part of the body. The main influencing factors are poor ergonomics and work organization.

Assessment of Benchmark Dose in BEAS-2B Cells by Evaluating the Cell Relative Viability with Particulates in Motorcycle Exhaust / 生物医学与环境科学（英文）

Objective@#This study aimed to use an air-liquid interface (ALI) exposure system to simulate the inhalation exposure of motorcycle exhaust particulates (MEPs) and then investigate the benchmark dose (BMD) of MEPs by evaluating cell relative viability (CRV) in lung epithelial BEAS-2B cells.@*Methods@#The MEPs dose was characterized by measuring the number concentration (NC), surface area concentration (SAC), and mass concentration (MC). BEAS-2B cells were exposed to MEPs at different concentrations @*Results@#Our results reveal that BMD of NC and SAC were estimated by the best-fitting Hill model, while MC was estimated by Polynomial model. The BMDL for CRV following ALI exposure to MEPs were as follows: 364.2#/cm @*Conclusion@#These results indicate that MEPs exposure

Analysis on the influencing factors of low back pain in the occupational workers of key industries in China / 中国职业医学

OBJECTIVE: To explore the influencing factors of low back pain and the relationship of the influence of bad working posture, weight load and frequency of load and the dose-response relationship among the occupational workers of key industries in China. METHODS: A total of 57 501 employees from 15 key industries in China were selected as research subjects using stratified cluster sampling method. The occurrence of low back pain in the past one year, as well as occupational factors such as job type, labor organization and work posture were investigated by using the Chinese version Musculoskeletal Disorders Questionnaire. RESULTS: The prevalence of low back pain in the occupational population of key industries in China was 16.4%(9 448/57 501). Multivariate Logistic regression analysis showed that the risk of low back pain in females was higher than that in males(P<0.01). Married, obese, occasional and frequent smokers, and a history of lower back disease were associated with increased risk of low back pain(all P<0.05). The risk of low back pain was associated with older age, higher education level, and lower frequency of physical exercise(all P<0.01). The risk of low back pain was higher with longer working time, greater back curvature, and the high frequency of long standing and sitting position work, uncomfortable working posture, repeated operation per minute, and lifting>5 kg weight(all P<0.01). CONCLUSION: The influencing factors of low back pain in the occupational population of key industries in China include bad working posture, high frequency load, weight load and other individual factors. There is a dose-response relationship with low back posture load and frequency of load.

How Work Organization Affects the Prevalence of WMSDs: A Case-control Study / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>In this study, we aimed at exploring the association between work-related musculoskeletal disorders (WMSDs) and work organization based on a case-control study.</p><p><b>METHODS</b>A total of 1938 workers who claimed to suffer from WMSDs were selected from Beijing, Henan, Hubei, and the Guangdong province. The control group consisted of 2009 workers employed in similar industries without severe disease or musculoskeletal discomforts. We used a modified version of the questionnaire developed by the NMQ and the DMQ to investigate individual and work-related factors.</p><p><b>RESULTS</b>A total of 13 variables (P<0.1) were selected by the chi-square test and finally, 7 variables entered into the equation, with 6 variables reaching statistical significance (P<0.05). The odds ratios (OR) of 'work changing with season' and 'sufficient rest time' did not reach 1 (0.749 and 0.441, respectively). In addition, 'sufficient rest time' seemed to be the stronger protective factor according to its higher standardized coefficient. And 'repetitive work every minute', 'constantly repetitive work' (every day), 'shortage of site personnel', and 'often switching shifts with others' seemed to be the risk factors.</p><p><b>CONCLUSION</b>Work organization may have comprehensive effects on the occurrence of WMSDs. This pattern of associations suggests that further investigation into the mechanism of how work organization affects the prevalence of WMSDs is required.</p>

The epidemiological study of work-related musculoskeletal disorders and related factors among automobile assembly workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the work-related musculoskeletal disorders among automobile assembly workers, to discusses the related risk factors and their relationship.</p><p><b>METHOD</b>The selected 1508 automobile assembly workers from a north car manufacturing company were regarded as the study object. The hazard zone jobs checklist, Nordic musculoskeletal symptom questionnaire (NMQ) and pain questionnaire were used to perform the epidemiological cross-sectional and retrospective survey and study for the General status, awkward ergonomics factors and related influencing factors, and musculoskeletal disorders of workers.</p><p><b>RESULTS</b>The predominant body sites of occurring WMSDs among automobile assembly workers were mainly low back, wrist, neck and shoulders, the predominant workshop section of occurring WMSDs were mostly concentrated in engine compartment, interior ornament, door cover, chassis and debugging section. The predominant body site of WMSDs among engine compartment and chassis section workers was low back, interior ornament workers were low back and wrist, door cover workers was wrist, chassis workers was low back, debugging workers were neck and low back. Neck musculoskeletal disorders had the trend with the increase of a body height; Smoking may increase the occurrence of musculoskeletal disorders.</p><p><b>CONCLUSION</b>The WMSDs appears to be a serious ergonomic proble assem among automobile assembly workers, predominant occurring site of WMSDs is with different workshop section, its characteristics is quite obvious, probably related to its existing awkward work position or activities. The worker height and smoking habits may be important factors which affect musculoskeletal disorders happen.</p>

Subject analysis of direct medical cost on pneumoconiosis patients with electronic records in an iron & steel enterprise / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the distribution of the direct medical cost for the pneumoconiosis and to provide the clue for the trauma insurance.</p><p><b>METHODS</b>936 cases including 109,530 records were divided into several groups by the stages of pneumoconiosis and categories of the cost. The groups (stage I, stage II, stage I with tuberculosis and stage II with tuberculosis) were analyzed by descriptive statistics and non-parameter test.</p><p><b>RESULTS</b>The medical cost of out-patient clinic was between 476.7 and 2307.9 yuan per patient per year. The hospitalization medical cost of stage I and II ranged from 3207.1 yuan to 7787.3 yuan per patient per year. There was no difference between stage I and II in statistically significant (P>0.05).</p><p><b>CONCLUSION</b>The lower and upper inter-quartile range of the total medical cost per patient per year is from 3207.1 yuan to 7787.3 yuan. In the categories of the hospitalization cost, drugs and bed fees attain a higher proportion.</p>

Analysis of direct medical cost on pneumoconiosis patients with questionnaires in an iron & steel enterprise / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the distribution of the direct medical cost for the pneumoconiosis and provide a clue for the compensation.</p><p><b>METHODS</b>According to the electronic records for the medical cost of pneumoconiosis, 237 patients were investigated with questionnaires. Their medical cost was described by disability levels, types of work, the categories of tuberculosis, ages and length of work.</p><p><b>RESULTS</b>In the 237 cases of questionnaires, there were 161 cases with complications, accounting for 67.9%, and the proportion of the emphysema in the complication cases was 21.1%. The proportion of the disability level IV for pneumoconiosis patients was about 55.7% in all cases. Their total medical cost ranged from 3946.5 yuan RMB to 8819.3 yuan RMB per patient per year, and the median was 6954.2 yuan RMB per patient per year.</p><p><b>CONCLUSION</b>The disability levels can be considered as the standard for the pneumoconiosis compensation to a certain extent.</p>

Mutagen sensitivity in peripheral blood lymphocytes among coke-oven workers / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the sensitivity to bleomycin (BLM) in peripheral blood lymphocytes (PBL) among coke-oven workers.</p><p><b>METHODS</b>Ninty-four coke-oven workers with exposure to a high level of polycyclic aromatic hydrocarbons and 64 non-coke-oven workers (control) were recruited into this study. PBL was challenged by 8 microg/ml BLM, a known carcinogen, to induce certain amount of DNA damage, the difference of olive tail moment (TM) measured by comet assay before and after BLM treatment reflected the sensitivity towards mutagens.</p><p><b>RESULTS</b>The distribution of age, sex, and prevalence of smoking and drinking were not significantly different between these two groups. The geometric mean of urinary 1-hydroxypyrene (1-OHP) was significantly higher in coke-oven workers than in controls (9.0 versus 1.5 microg/L, t = -9.317, P < 0.01). The coke-oven workers showed significantly higher sensitivity to BLM than controls (17.7 versus 14.9, t = -2.583, P = 0.01). A large inter-group difference in sensitivity to BLM was observed in both controls and coke-oven workers. Stratification analysis revealed the significant association between high 1-OHP level (> 9.0 microg/L) and increased sensitivity to BLM (F = 4.001, P = 0.05) among coke-oven workers. Smoking subjects showed a significant higher value of sensitivity than nonsmokers in controls but not in coke-oven workers. No significant difference was observed between age, drinking status, coking history or external exposure class and BLM sensitivity.</p><p><b>CONCLUSION</b>Exposure to coke oven emission could increase the sensitivity to mutagens, which might be a reason of high incidence of lung cancer among coke-oven workers.</p>

Genetic damage in peripheral blood lymphocyte of coke oven workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate DNA and chromosome damage in peripheral blood lymphocyte of coke oven workers exposed to polycyclic aromatic hydrocarbons (PAHs).</p><p><b>METHODS</b>One hundred and thirty-seven coke oven workers and 50 controls without occupational PAHs exposure were investigated. Comet assay and cytokinesis-block micronucleus (CBMN) detection were used to evaluate DNA and chromosomal damage levels in peripheral blood lymphocyte. Urinary 1-hydroxypyrene level was used to assess the personal internal PAHs exposure dose. Personal information including occupational history, age, sex, smoking and drinking status was collected by questionnaire.</p><p><b>RESULTS</b>Urinary 1-hydroxypyrene level in coke oven workers [(5.76 +/- 1.04) micro mol/mol Cr] was significantly higher than that in controls [(0.70 +/- 0.32) micro mol/mol Cr]. The rate of CBMN and comet tail moment of lymphocyte in coke oven workers [8.0 per thousand (0.0 per thousand - 30.0 per thousand ) and 2.09 (0.31 - 75.41), respectively] were higher than those in controls [3.5 per thousand (0.0 per thousand - 13.0 per thousand ) and 1.05 (0.11 - 6.63), P < 0.05]. In controls, the comet moment in smokers was significantly higher than that in non-smokers [1.44 (0.23 - 6.63) vs 0.81 (0.11 - 3.47), P < 0.05]. According to the length of work, 137 coke oven workers were classified into 3 groups i.e. 0.5 yrs , 16.0 yrs and 22.0 yrs group, and the comet moments were 1.34 (0.31 - 37.84), 2.32 (0.49 - 52.97) and 3.20 (0.45 - 75.41) respectively after adjusting the age, sex, smoking, drinking and level of urinary 1-hydroxy-pyrene. There was a rising tendency along with the increase in length of work.</p><p><b>CONCLUSION</b>Under present PAHs exposure levels, both comet assay and Cytokinesis-block micronucleus test could detect PAHs-induced genotoxicity in coke oven workers, and comet assay is more suitable to assess the cumulative damage effect on DNA.</p>

A study on the inherited susceptibility of chromosomal damage in peripheral blood lymphocytes among coke oven workers / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the association between polymorphisms of metabolic enzyme genes and chromosomal damage risk in peripheral blood lymphocytes among coke oven workers.</p><p><b>METHODS</b>One hundred and fourty-nine coke oven workers and 24 referents without occupational polycyclic aromatic hydrocarbons (PAH) exposure were recruited in this study. Urinary 1-hydroxypyrene levels were measured as the internal dose of PAH exposure. The 6 per 1 000 of micronucleus value was used as the cut-off value to determine whether the individual's chromosomal damage was positive. The genotypes of CYP1A1, GSTM1, GSTT1, GSTP1, CYP2E1, NQO1, NAT2 and mEH genes were determined by PCR-based methods. Multiple logistic regression was used to calculate the adjusted ORs and the 95% CI for the risk of chromosomal damage and to analyze the gene-gene interaction.</p><p><b>RESULTS</b>In 173 subjects, after adjusting the occupational exposure, age, sex, smoking and drinking status, the subjects with GSTM1 null genotype have significantly higher risk for chromosomal damage than subjects with GSTM1 positive genotype (adjusted OR = 2.01, 95% CI = 1.03 -3.91). Compared with the wild homozygotes at P187S site of NQO1 gene, the variant homozygotes have significantly higher risk for chromosomal damage (adjusted OR = 3.18, 95% CI = 1.18 - 8.62). The subjects with variant allele at H113Y site of mEH gene have significantly lower risk for chromosomal damage (adjusted OR = 0.40, 95% CI = 0.19 - 0.88). No significant associations were found for other gene polymorphisms and chromosomal damage risk. In addition, the gene-gene interactions were also found among GSTM1, NQO1 gene P187S and mEH gene H113Y polymorphisms for the risk of chromosomal damage risk.</p><p><b>CONCLUSION</b>Significant associations between genetic polymorphisms in GSTM1, NQO1 and mEH gene and risk for chromosomal damage were found among occupational PAH-exposed workers, which related to the mechanism of PAH carcinogenesis.</p>

Relationship of polycyclic aromatic hydrocarbon exposure with peripheral blood lymphocyte DNA damage in coke oven workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between lymphocyte DNA damage and polycyclic aromatic hydrocarbons (PAHs) exposure in coke oven workers.</p><p><b>METHODS</b>Two hundred and thirty-five coke oven workers and 30 controls were selected in this study. Alkaline single-cell gel electrophoresis was used to evaluate the lymphocyte DNA damage, HPLC was employed to measure 1-hydroxypyrene levels in spot urine samples which were obtained at the end of a workweek (4 days of 8 hours/day) and personal information including occupational exposure, age, sex, smoking and drinking status was collected by the questionnaire.</p><p><b>RESULTS</b>The lymphocyte DNA damage level expressed as olive moment in coke oven workers was significantly higher than that of controls [2.47 (0.22 approximately 46.68) vs 0.94 (0.42 approximately 4.21), P < 0.01], and correlation between urinary 1-hydroxypyrene concentrations and olive moment was found (Spearman Partial correlation coefficient = 0.22, P < 0.01) in coke oven workers. The 1.9 of olive moment value was used as the limit to determine whether the subject DNA damage was positive. The coke oven workers had significantly higher risk in DNA damage (adjusted OR = 5.38, 95% CI = 2.07 approximately 14.08) than did controls, and dose-response relationships were also found between external exposure (exposure category) or internal doses (urinary 1-hydroxypyrene) and DNA damage.</p><p><b>CONCLUSION</b>There are dose-effect and dose-response relationships between PAHs exposure and lymphocyte DNA damage in coke oven workers.</p>

A study on the relationship between urinary 1-hydroxypyrene level and early genetic effect among coke oven workers / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the urinary 1-hydroxypyrene level and cytokinesis-block micronucleus and the olive moment of comet assay in peripheral blood lymphocyte in coke oven workers.</p><p><b>METHODS</b>One hundred and thirty-three workers from a coke plant and 28 referents without occupational PAH exposure were recruited in this study. Urinary level of 1-hydroxypyrene was measured by alkaline hydrolysis combined with high performance liquid chromatography as an internal exposure dose, and the DNA and chromosomal damage of peripheral blood lymphocyte were evaluated with comet assay and cytokinesis-block micronucleus method. Personal information including occupational history, age, sex, smoking and alcohol drinking, was collected by questionnaire.</p><p><b>RESULTS</b>There existed a good correlationship between the urinary level of 1-hydroxypyrene and frequency of micronuclei per 1 000 binucleated cells or the olive moment of comet assay in the study subjects, after adjusting for sex, age, smoking and alcohol drinking (r > 0.25, P < 0.01). One hundred and sixty-one subjects were divided into three groups by their urine 1-hydroxypyrene level (expressed as 0.30 - 2.44, 2.45 - 7.09 and 7.10 - 33.10 micro mol/mol Cr), and the geometric means of their urinary levels of 1-hydroxypyrene were 1.14, 4.32 and 12.49 micro mol/mol Cr, respectively. After adjusting for age, sex, smoking and alcohol drinking by multiple nonparametric analysis of covariance, the median of olive moment of comet assay in the group of 7.10 - 33.10 micro mol/mol Cr was 3.67, significantly higher than that in the groups of 0.30 - 2.44 and 2.45 - 7.09; and the micronuclei frequencies in the groups of 2.45 - 7.09 and 7.10 - 33.10 micro mol/mol Cr were 8.00 per thousand and 7.50 per thousand, respectively, significantly higher than that in the group of 0.30 - 2.44 micro mol/mol Cr (6.00 per thousand ).</p><p><b>CONCLUSIONS</b>The comet assay of peripheral blood lymphocyte was more suitable to detect the PAHs-induced early genotoxicity, than the cytokinesis-block micronucleus.</p>