05) . CX-5461 DNA inhibitor After adjusting for factors such as passive smoking and drinking, the results of the multiple linear regression model showed that menopausal age, menstrual years were negatively correlated with shift work (β=-0.493, -0.575, P less then 0.05) . Conclusion Shifts are related to women’s menopausal age and menstrual years, and attention should be paid to the impact of work intensity and circadian rhythm on the occupational health of female employees.Objective To explore the short-term effects of welding fumes on workers’ lung function in the welding environment preliminarily, and provide reference for future research. Methods In October 2020, the lung function of the subjects was repeatedly measured before and after the working shift with a panel study. The paired t test was used to compare the lung function before and after the shift, and the linear mixed effects model was used to analyze the short-term changes of lung function. Results 36 male welders were included, and the average age was (30.72±5.21) years, average employed year was (4.36±2.17) years. And the average concentration of welding fume was (1.27±0.49) mg/m(3). The forced vital capacity (FVC) , forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF) of welders after the shift were significantly lower than those before the shift (t=19.52, 48.13, 62.03, P less then 0.05) . After adjusting the workers’ age, BMI and employed years, the changes of FVC% and FEV1% with the concentration of welding fume were statistically significant (β=-1.02, 95%CI -1.54–0.52; β=-1.56, 95%CI -1.95–1.16; P less then 0.01) . In another word, for the 1 mg/m(3) increase of welding fume in the working environment, compared with the baseline, the FVC decreases by 1.02%, and FEV1 decreases by 1.56%. Conclusion Short-term exposure to welding fumes in workplace can reduce the lung function of welders.Objective A gas chromatography-tandem mass spectrometry detection method for benzene and its metabolites was established to provide methodological support and theoretical basis for the study of benzene toxicity mechanism. Methods In August 2019 to March 2020, the animal model of containing high concentration of benzene by inhalation of poison through the respiratory tract of mice was established, taken the blood of mice after dyeing the poison, and the HLB solid phase extraction method was used to extract and purify the samples. The gas chromatography-tandem mass spectrometry detection method was used to qualitative and quantitative analysis of the target substances. After separated by HP-17MS capillary chromatographic column, the compounds were ionized with EI ion source, mass spectrometry detection was carried out by selective ion scanning method (SIM) , and quantification was carried out by external standard curve method. Results Benzene and its metabolites (phenol, catechol, hydroquinone and m-trihydroxybcan be used for qualitative and quantitative detection of benzene and its metabolites (phenol, catechol, hydroquinone and m-trihydroxybenzene) accurately.Objective To investigate the value of fractional exhaled nitric oxide (FeNO) in the diagnosis of occupational asthma (OA) , and analyze the correlation between FeNO and pulmonary function in patients with OA. Methods In October 2019, clinical datas, including pulmonary function, FeNO and blood routine test of 64 workers who applied for the diagnosis of OA in January 2012 to October 2018 in our hospital were collected. The diagnostic value of FeNO in OA was evaluated, FeNO and pulmonary function in different degrees of OA were compared, and the correlations were analyzed. Results The FeNO value of OA patients [ (58.4±13.1) ppb] was higher than non-OA patients[ (30.1±13.7) ppb] (P less then 0.05) . The FeNO value of patients with moderate OA [ (68.9±13.8) ppb] was higher than that of patients with mild OA[ (54.2±10.3) ppb] (P less then 0.05) . The area under the receiver operating characteristic (ROC) curve of FeNO in the diagnosis of OA was 0.9453 (95%CI 0.8928-0.9978, P less then 0.05) , the optimal cut-off point is 47.5 ppb, and the sensitivity and specificity are 88.6% and 89.7% respectively. There was negative correlation between FeNO and FEV1% pred (r=-0.454, P less then 0.01) . Conclusion FeNO has a clinical application value in the diagnosis of OA. It should be combined with pulmonary function index in practical work.Objective To explore the CT grading method of small opacity profusion of pneumoconiosis, and draw up the corresponding CT reference film. Methods In December 2019, Three hundred thirty-seven cases of pneumoconosis and suspected pneumoconiosis were examined by chest radiography and Computed Tomography (CT) in the same period. According to Diagnosis of Occupational Pneumoconiosis (GBZ 70-2015) , small opacity profusion of pneumoconiosis in each zone of lung was divided. On CT scans, it was divided into 5 grades of 0, 0+, 1, 2 and 3. Grade 0 corresponded to Sub-grade 0/- and Sub-grade 0/0 of Grade 0 in chest radiograph. Grade 0+ was equivalent to Sub-grade 0/1 of Grade 0. Grade 1, 2, 3 were equivalent to Grade 1, 2 and 3, respectively (including each sub-grade) . The CT image quality of each zone of lung was divided into 1 to 4 levels. Results of level 4 were not included in statistical analyses.Based on the results of small opacity profusion in each zone of lung, consistency analysis was performed between chest radiograph and CT. The selection method of reference films was developed. Based on the types and grades of small opacity, the final reference films were determined. Results There were 1877 zones of lung with CT image quality from level 1 to 3, including 335 in upper right, 319 in middle right, 284 in lower right, 334 in upper left, 320 in middle left and 286 in lower left. The Kappa values of small opacity profusion in upper right zone, upper left zone, left middle zone, and lower left zone were all between 0.4-0.75. In middle right zone and lower right zone, they were all above 0.75.Among all 6 zones of lung, the diagnostic concordance rates between CT and chest radiograph were all above 80%.The corresponding CT reference films were proposed, including type p and q in Grade 2 and 3, type r in Grade 2, type s and t in Grade 0+ to 3. Conclusion The CT grading method for small opacity profusion of pneumoconiosis is feasible, and the application value of its reference films needs to be further verified.