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OBJECTIVE: To investigate the effect of the power-frequency electromagnetic field on antioxidant indexes in operation personnel. METHODS: By random sampling method,a total of 58 workers who work in 500 kV transformer substations for at least 5. 0 years were selected as the exposure group,and 60 administrative staffs in the same enterprise were included as the control group. The power frequency electromagnetic fields in the 2 groups were measured. The cumulative exposure dose of individual magnetic field was calculated. Peripheral venous blood was collected in these 2groups and was examined with the superoxide dismutase( SOD) activity,malondialdehyde( MDA) level and the relative gene expression level of manganese superoxide dismutase( MnSOD). RESULTS: There was no statistical significance in the SOD activity,MDA level and the relative gene expression level of MnSOD between the exposure group and the control group( P > 0. 05). The logistic regression analysis results indicated that cumulative exposure dose was not correlated with the SOD activity,MDA level and the relative gene expression level of MnSOD after adjusting confounding factors such as age,smoking,alcohol and tea drinking( P > 0. 05). CONCLUSION: Power-frequency electromagnetic field exposure has no significant effects on the SOD activity,MDA level and the relative gene expression level of MnSOD of operation workers.
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<p><b>OBJECTIVE</b>To investigate the incidence of welder's pneumoconiosis in container manufacturing industries in Guangdong province and present some preventive and curative strategy.</p><p><b>METHODS</b>Occupational epidemiology study methods were used to study the incidence of welder's pneumoconiosis in two container manufacturing enterprises (enterprise A and enterprise B).</p><p><b>RESULTS</b>Before 2004, the rate of up-to-standard of weld fume concentration in the workplaces was relatively low (< or = 40%), and the maximum value of time weighted average (TWA) was 26.7 mg/m(3). After 2004, with the system of dust control, the rate of up-to-standard was 85% in the enterprise A. Of the 813 weld workers examined, 19 were diagnosed as welder's pneumoconiosis (stage I was 15, while I (+) was 4 ) and the incidence was 2.34% (19/813). The age of electric welders suffering from welder's pneumoconiosis and the duration of dust exposure were (33.45 + 4.64) and (8.04 + 1.97) years respectively. Chest radiographic examination showed mainly small round opacities "p". The value of MVV, FEF25%, FEF50% and FEF75% in lung function tests were significantly lower than those of the control group (P < 0.05 or P < 0.01).</p><p><b>CONCLUSION</b>The main features of welder's pneumoconiosis in container manufacturing industries are the short duration of dust exposure, and small round opacities "p" in the chest radiographs. Therefore, it should be the key point of the prevention and treatment of occupational diseases in this industry to control the harmful weld fume.</p>
Subject(s)
Adult , Female , Humans , Male , China , Epidemiology , Dust , Occupational Exposure , Pneumoconiosis , Epidemiology , WeldingABSTRACT
<p><b>OBJECTIVE</b>To study the hazards of gem dusts and the epidemiological features of the occurrence of gem worker's silicosis (GWS).</p><p><b>METHODS</b>Epidemiological investigation in a gem factory in Guangdong province was carried out.</p><p><b>RESULTS</b>The average dusts concentration in workshop was 2.3 mg/m(3), average free silica content was 94.64%. There were 47 patients diagnosed as silicosis. The prevalence of GWS was 4.58% (47/ 1,027). The age of patients suffering from silicosis and the duration of dust exposure were (27.04 +/- 3.25) years and (4.67 +/- 1.17) years respectively. Chest radiographic examination showed mainly small round opacities "q". The incidences of GWS complicated by pulmonary tuberculosis, spontaneous pneumothorax and pulmonary emphysema were 10.64%, 10.64%, 44.68% respectively.</p><p><b>CONCLUSION</b>The hazards of gem dust to workers might be serious. Higher incidence, younger age suffered from silicosis, shorter duration of dust exposure, more complications, and poorer prognosis in gem workers appeared to be the main epidemiological features of GWS in Guangdong.</p>