The method of determination for butyronitrile and isobutyronitrile in the air of workplace by dissolved desorption-gas chromatography / 中华劳动卫生职业病杂志

Objective: To establish a method for the determination of butyronitrile and isobutyronitrile in the air of workplace by gas chromatography. Methods: In March 2020, butyronitrile and isobutyronitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatogram with flame ionization detector, the characteristics of determination of nitrile and isobutyronitrile by gas chromatography were analyzed. Results: The limit of detection for butyronitrile and isobutyronitrile was 0.33 μg/ml. The linear range of butyronitrile determined by this method was 1.60-1600.00 μg/ml, y=2.295x-3.480, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.43%-4.12%, the between-run precisions were 1.72%-3.70%, and the desorption rates were 93.26%-98.41%. The linear range of isobutyronitrile determined by this method was 1.52-1520.00 μg/ml, y=2.208x-0.102, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.52%-3.22%, the between-run precisions were 1.20%-3.82%, and the desorption rates were 96.85%-102.50%. The sealed samples could be stored at least 10 days at room temperature without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the simultaneous determination of butyronitrile and isobutyronitrile in the air of workplace.

Determination of 15 kinds of vapor state organic acids in workplace air by dissolved desorption-gas chromatography / 中国职业医学

OBJECTIVE: To establish a method for simultaneous determination of 15 kinds of vapor state organic acids in workplace air by solvent desorption-gas chromatography.METHODS: A total 15 kinds of vapor state organic acids such as acetic acid, propanoic acid, butyric acid and pentanoic acid in the air of workplace were collected by silica gel, eluted with acetone, separated by DB-FFAP capillary chromatograph column, and detected by gas chromatography with flame ionization detection. RESULTS: There was a good linear relationship in the selected range of 15 kinds of organic acids. The coefficient correlation was 0.999 97-0.999 98. The limit of detection of this method was 0.04-0.29 mg/L, and the minimum detection concentration was 0.03-0.19 mg/m~(3 )(collected sample volume was 1.50 L). The average desorption efficiency was 92.9%-98.5%. The within-run and between-run relative standard deviation was 0.3%-1.6% and 1.5%-3.0%, respectively. The samples could be kept for at least 15 days at room temperature. CONCLUSION: The method is simple for operation, with high sensitivity, and good precision, which is suitable for simultaneous determination of 15 kinds of vapor state organic acids in the air of workplace and sites of emergency accident.

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 interactive effect of job task and psychosocial factors on work-related musculoskeletal disorders / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the interactive effect of job task and psychosocial factors on the outcomes of musculoskeletal disorders.</p><p><b>METHODS</b>653 workers from different type of manufacturing industries and administration office recruited in a cross-sectional epidemiological survey. The Quick Exposure Check (QEC) was applied to assess the ergonomic load of job task, Job Content Questionnaire (JCQ) for identifying psychological characteristics, and Nordic Standardized Questionnaire for investigating outcomes of WMSDs.</p><p><b>RESULTS</b>The prevalence of WMSD in shoulder, upper back, lower back and hand/wrist were significantly different under a variety of combined job task and psychosocial characteristics (P < 0.05 or P < 0.01). The more physical and psychological loads, the higher prevalence of WMSDs were revealed. By using multivariate analyses, a potential interactive effect was found in terms of the WMSDs symptoms in hand/wrist, shoulder, upper back and lower back after adjusted by work year, age, and gender.</p><p><b>CONCLUSIONS</b>Higher physical load and greater psychosocial risk are more frequent self-reported symptoms of WMSDs than those of lower exposures. Ergonomic intervention strategies aimed at reducing the incidence of WMSDs should not only be focused on control of physical work factors but also psychosocial risks of relevance.</p>