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OBJECTIVE: To evaluate the application value of finger systolic blood pressure(FSBP) in the diagnosis of vibration-induced vascular injury. METHODS: Thirty patients with vibration-induced vascular injury [vibration-induced white finger(VWF)] were selected as the case group by a non-randomized concurrent controlled trial, and 30 hand-transmitted vibration workers without VWF were selected as the control group. The FSBP test was performed on the tested hands of all subjects, and the FSBP index of each Finger(F_( i)) was measured. RESULTS: The F_i of the index finger, middle finger, ring finger and tail finger of the tested hand in the case group were lower than that in the control group(all P<0.01). In the case group, the F_i of index finger was lower than ring finger and tail finger(all P<0.01). The abnormal rates of F_i on the index, middle and ring fingers in the case group were higher than those in the control group(86.7% vs 10.0%, 76.7% vs 13.3%, 43.3% vs 10.0%, all P<0.01). The area under the receiver operator characteristic curve of the measured F_i of the index finger, middle finger, ring finger and tail finger were 0.884, 0.843, 0.764 and 0.687 respectively. The diagnostic cut off value of the F_i of index finger was 80.2%. The sensitivity and specificity were 86.7% and 90.0%, respectively. CONCLUSION: FSBP test has a good application value in the diagnosis of vibration-induced vascular injuries. It is suggested that the F_i of index finger be the first choice as the diagnostic index, and the abnormal value can be set at 80.0%.
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OBJECTIVE: To test and analyze the vibration transmissivity of three common kinds of protective gloves, and to determine their actual protecting effect. METHODS: Three kinds of protective gloves were selected as test materials, and five healthy volunteers were selected as subjects using typical sampling methods. According to the ISO 10819:2013 Mechanical Vibration and Shock--Hand-arm Vibration--Measurement and Evaluation of the Vibration Transmissibility of Gloves at the Palm of the Hand(hereinafter referred to as ISO 10819:2013), investigation and measurement of basic parameters of protective gloves. The gloved vibration transmission(GVT) test system was used to test the vibration transmission of different protective gloves worn by the subjects, and the spectrum analysis of vibration reduction characteristics was carried out. RESULTS: The thickness of damping material of all the three kinds of protective gloves met the standard requirements. The mean value for the corrected frequency-weighted glove vibration transmissibility values at 25.0-200.0 Hz were 0.91, 0.75 and 0.94, and 1.05, 0.85 and 1.10 at 200.0-1 250.0 Hz, for the protective gloves A, B and C, respectively. The results of anti-vibration characteristic spectrum analysis show that there has no vibration reduction effect at the frequency of 25.0-200.0 Hz when wearing these three kinds of gloves. Wearing gloves A and B on part of the 200.0-1 250.0 Hz frequency vibration has an amplifying effect. Wearing glove C has a partial vibration reduction effect at the 200.0-1 250.0 Hz frequency, and the vibration reduction efficiency is the highest at the frequency of 1 250.0 Hz.CONCLUSION: According to the ISO 10819:2013 standard, the mean value of GVT measured when wearing the three kinds of protective gloves does not meet the relevant requirements, and the anti-vibration effect is poor. These gloves cannot be defined as anti-vibration gloves.
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Aim To investigate the effect of salvianolic acid B(Sal B) on the attenuation of rat hepatocyte in-jury induced by hypoxia/reoxygenation(H/R) and its possible molecular mechanism. Methods Rat hepato-cytes BRL-3A were cultured in vitro. H/R injury mod-el was established and then BRL-3A cells were pretrea-ted with Sal B. The viability of cells was measured by CCK-8 assay;the expression of ALT and AST was de-tected by microplate assay; the levels of TNF-α and IL-1β were determined by ELISA; the apoptosis was detected by flow cytometry;the protein and mRNA lev-els of SIRT1, NF-κB p65, p53, Bax and Bcl-2 were measured by Western blot and qPCR. Results H/R intervention decreased the viability and increased the apoptosis of cells;the production of ALT, AST, TNF-α and IL-1β was elevated;the protein and mRNA lev-els of SIRT1, Bcl-2 were reduced, but the levels of NF-κB p65, p53 and Bax increased. After pretreated with Sal B, the viability of cells increased while the apoptosis decreased; the expression of ALT, AST, TNF-α and IL-1β was inhibited;moreover,the protein and mRNA levels of SIRT1,Bcl-2 were enhanced,and the levels of NF-κB p65, p53 and Bax decreased sig-nificantly. Conclusion Sal B may attenuate rat hepa-tocyte injury induced by H/R via the SIRT1/NF-κB/p53 pathway.
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OBJECTIVE: To study the occupational exposure characteristics of hand-transmitted vibration in hand-held workpiece polishing and to provide the basis for occupational hazard prevention and control technology research in this kind of job. METHODS: The questionnaire and on site occupational health investigation were used to study 4 typical enterprises of hand-held workpiece polishing. The study was conducted by filling forms by enterprise,personal interviews with administrative staffs and front-line workers,as well as on site visit. RESULTS: Among the 4 factories,there were 835workers( 22. 4%) engaged in the hand-held workpiece polishing assignment. The principal vibrating tools used in these 4factories were polishing machine,flint glazing machine and polishing wheel,and the workpiece polished by workers were button,toilet lid,thermos,mobile phone shell and golf head. The polishing workers were all equipped with noise reduction earplugs and anti-dust respirators, but they did not wear anti-vibration gloves. The hand-held workpiece polishing assignment has the characteristics including indirect and continuous vibration exposure and fine operation. Some workers used their knees and abdomens as the support to polish workpieces. The vibration exposure time was 6-11 h / d. The 4hours energy equivalent frequency-weighted acceleration to vibration [ahw( 4)]was 1. 9-19. 4 m/s~2,with the maximum which exceeded the occupational exposure limit( 5. 0 m / s~2),showing a wide range ahw( 4)in the same enterprise. CONCLUSION: Compared with the traditional vibrating tools,the hand-held workpiece polishing operation has different characteristics of hand-transmitted vibration such as more sophisticated machine structure,finer polishing ways,more influencing factors of vibration exposure level and more extensive body parts involved.
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OBJECTIVE: To analyze the effects of hand-transmitted vibration exposure on the finger vibratory and pain perception thresholds among drill workers in a gold mine. METHODS: By the judgement sampling method,134 male drill workers from a gold mine in the northern area of China were selected as the hand-transmitted vibration exposure group and102 fit-up workers without vibration exposure in the same mine were chosen as the control group. The finger vibratory perception thresholds,the pain perception thresholds and the occupational health examination were conducted and analyzed in these two groups. Based on the self-report with vibration-induced white finger( VWF),the workers of hand-transmitted vibration exposure group were divided into non-VWF subgroup( 105 workers) and VWF subgroup( 29 workers). RESULTS: The incidence of finger numbness,pain and self-reported white finger in the exposure group were significantly higher than those in the control group( P < 0. 05). Compared with the control group,the vibratory perception thresholds of the index finger,middle finger and ring finger of the right hand among the vibration exposure group workers were significantly higher( P < 0. 05),but there was no significant difference in the vibratory perception thresholds of the left ring finger between the two groups( P > 0. 05). The vibratory perception thresholds of both ring fingers,right index finger and right middle-finger in VWF subgroup were higher than those in control group( P < 0. 05). But no significant differences was found in the above 4 indexes in these two groups after compared to those of control group,respectively( P > 0. 05). The vibratory perception thresholds of left ring finger,right ring finger and right index finger in VWF subgroup were all higher than those in non-VWF subgroup( P < 0. 05),but the vibratory perception thresholds of right middle finger in these two groups showed no significant difference( P > 0. 05). The pain perception thresholds of index finger,middle finger and ring finger in both hands of the vibration exposure group workers were all higher than those in control group( P < 0. 05). The pain perception thresholds of middle finger and ring finger in both hands of the VWF subgroup and non-VWF subgroup were higher than those of control group( P < 0. 05). CONCLUSION: The hand-transmitted vibration can increase the thresholds of finger vibratory and pain perception in drill workers. The finger sensory perception examination could be used to assist the early detection of peripheral nerve damage induced by hand-transmitted vibration.
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OBJECTIVE: To analyze the correlation between four vessel regulate factors and vibration-induced white finger( VWF) evaluating in workers exposed to hand-arm vibration,and discuss the value of regulate factors for VWF screening.METHODS: Using typical sampling method,77 male workers exposed to hand-arm vibration with more than 1 year of polish work from a metalwork factory were selected as the study subjects. Based on the workers' self-report,they were divided into VWF group( 43 workers) and non-VWF group( 34 workers). The venous blood from center elbow was collected and plasma was separated. The plasma level of endothelin( ET) was detected by radioimmunoassay. The plasma levels of transforming growth factor beta( TGF-β),soluble intercellular adhesion molecule-1( s ICAM-1) and 5-hydroxytryptamine( 5-HT) were detected by enzyme-linked immunosorbent assay. The regulate factors for evaluating VWF were screened and the new multivariable model index
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OBJECTIVE: To evaluate the major influence factors affecting the quality and accuracy of measuring instruments for power frequency electromagnetic fields in occupational hygiene technical service organizations by developing interlaboratory comparison in workplaces. METHODS: Six measuring instruments for power electromagnetic fields from 6occupational hygiene technical service organizations in Guangdong Province were selected by typical sampling method. A high-voltage substation was selected as a standard source. We set measurement sites underneath it as inter-laboratory comparison spots for power frequency electromagnetic fields. The stability of the standard source was evaluated by pairedsamples t-test and measure results were analyzed by z-score evaluation method based on quartile robust statistical technology. RESULTS: During and after the inter-laboratory comparison,the intensity of electric field and magnetic field of the standard source showed no significant difference [( 555. 03 ± 2. 94) vs( 555. 68 ± 3. 20) V / m,( 2. 30 ± 0. 06) vs( 2. 29 ± 0. 07) μT,P > 0. 05],which met the demand of stability of inter-laboratory comparison. The data of electric field measured by 2 measuring instruments without remote-reading system were found to be high because of proximity effect from its handheld status. The z-score of inter-laboratory( zB) of other 4 measuring instruments with remote-reading system ranged from- 0. 52 to 1. 10,while the z-score of within-laboratory( zW) ranged from- 1. 28 to 0. 37,and both results of| zB| and | zW| were satisfactory( < 2. 00). The zBof power frequency magnetic field measured by the 6 measuring instruments ranged from- 0. 67 to 1. 26,while zWranged from- 0. 59 to 0. 90,and both | zB| and | zW| were also satisfactory( < 2. 00). CONCLUSION: It is feasible that the inter-laboratory comparison of measuring instruments of power frequency electromagnetic fields could be implemented by a high-voltage substation as a standard source. The measuring instruments without remote-reading system could be used to measure the intensity of magnetic field but not the electric field. The measuring instruments with remote-reading system could be used to measure the intensity of either the electric field or the magnetic field,and the measurement results are satisfactory.
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<p><b>OBJECTIVE</b>To compare the results of noise hazard evaluations based on area sampling and personal sampling in a new thermal power plant and to analyze the similarities and differences between the two measurement methods.</p><p><b>METHODS</b>According to Measurement of Physical agents in Workplace Part 8: Noise(GBZff 189.8-2007), area sampling was performed at various operating points for noise measurement, and meanwhile the workers under different types of work wore noise dosimeters for personal noise exposure measurement. The two measurement methods were used to evaluate the level of noise hazards in the enterprise according to the corresponding occupational health standards, and the evaluation results were compared.</p><p><b>RESULTS</b>Area sampling was performed at 99 operating points, the mean noise level was 88.9 ± 11.1 dB (A)(range, 51.3-107.0 dB (A)), with an over-standard rate of 75.8%. Personal sampling was performed (73 person times),and the mean noise level was 79.3 ± 6.3 dB (A), with an over-standard rate of 6.6% ( 16/241 ). There was a statistically significant difference in the over-standard rate between the evaluation results of the two measurement methods ( x2=53.869, ?<0.001 ).</p><p><b>CONCLUSION</b>Because of the characteristics of the work in new thermal power plants, the noise hazard evaluation based on area sampling cannot be used instead of personal noise exposure measurement among workers. Personal sampling should be used in the noise measurement in new thermal power plant.</p>
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Environmental Monitoring , Methods , Noise, Occupational , Power PlantsABSTRACT
<p><b>OBJECTIVE</b>To measure and assess the levels of occupational exposure to power frequency electromagnetic fields in workers of power grid.</p><p><b>METHODS</b>PMM8053 electromagnetic fields measuring system with EHP-50 probe was used to measure the levels of electromagnetic fields at working place. Personal dosimeters (EMDEX LITE) were utilized to measure the individual exposure levels of power frequency magnetic field. The results were evaluated with the limitation criteria of GBZ2.2 and ICNIRP.</p><p><b>RESULTS</b>In the 500 kV ultra high voltage substation, the intensity at 90% measure points of power electric field was more than 5 kV/m. The magnetic field intensity in the areas nearby reactors and capacitors was often higher than 100 µT, even several hundreds µT. The mean daily exposure levels of workers in power grid were between 0.04 and 5.0 µT, and the exposure levels of 70% workers were higher than 0.4 µT.</p><p><b>CONCLUSION</b>In the areas of ultra high voltage and nearby the reactors and capacitors are the key control points for occupational health in power grid. There is acute health risk of workers exposed to high accumulative exposure levels.</p>