Objective To investigate the clinical value of ultrasound examination of carpal canal structure in patients with mild hand-arm vibration disease.Methods A total of 29 patients (58 wrists) with mild hand-arm vibration disease who were treated in Shenzhen Prevention and Treatment Center for Occupational Diseases from May to December,2015 were enrolled as observation group,and 20 healthy volunteers (40 wrists) were enrolled as the control group.Color Doppler ultrasound was used to observe the morphology and echo of the median nerve in the carpal canal and 9 muscle tendons and transverse carpal ligament.The thickness of transverse carpal ligament and diameter of the median nerve at the level of the hamulus of hamate bone were measured,as well as the cross-sectional area of the median nerve at the level of pisiform bone.Results In the 29 patients with hand-arm vibration disease patients in the observation group,8 experienced entrapment of the median nerve in the carpal canal,among whom 5 had entrapment in both wrists;there were 13 wrists (23％) with nerve entrapment and 45 wrists (77％) without nerve entrapment.Compared with the control group,the patients with hand-arm vibration disease and nerve entrapment in the observation group showed significant thickening of the transverse carpal ligament at the level of the hamulus of hamate bone and a significant increase in the crosssectional area of the median nerve at the level of pisiform bone (P＜0.05),while there were no significant differences in the thickness of transverse carpal ligament at the level of the hamulus of hamate bone and the crosssectional area of the median nerve at the level of pisiform bone (t=-9.397 and-4.385,both P＞0.05).Conclusion Ultrasound examination can clearly show the radiological changes of carpal canal contents in patients with mild hand-arm vibration disease and has a certain diagnostic value in nerve damage in patients with hand-arm vibration disease.

Objective To investigate the clinical value of ultrasound examination of carpal canal structure in patients with mild hand-arm vibration disease.Methods A total of 29 patients (58 wrists) with mild hand-arm vibration disease who were treated in Shenzhen Prevention and Treatment Center for Occupational Diseases from May to December,2015 were enrolled as observation group,and 20 healthy volunteers (40 wrists) were enrolled as the control group.Color Doppler ultrasound was used to observe the morphology and echo of the median nerve in the carpal canal and 9 muscle tendons and transverse carpal ligament.The thickness of transverse carpal ligament and diameter of the median nerve at the level of the hamulus of hamate bone were measured,as well as the cross-sectional area of the median nerve at the level of pisiform bone.Results In the 29 patients with hand-arm vibration disease patients in the observation group,8 experienced entrapment of the median nerve in the carpal canal,among whom 5 had entrapment in both wrists;there were 13 wrists (23％) with nerve entrapment and 45 wrists (77％) without nerve entrapment.Compared with the control group,the patients with hand-arm vibration disease and nerve entrapment in the observation group showed significant thickening of the transverse carpal ligament at the level of the hamulus of hamate bone and a significant increase in the crosssectional area of the median nerve at the level of pisiform bone (P＜0.05),while there were no significant differences in the thickness of transverse carpal ligament at the level of the hamulus of hamate bone and the crosssectional area of the median nerve at the level of pisiform bone (t=-9.397 and-4.385,both P＞0.05).Conclusion Ultrasound examination can clearly show the radiological changes of carpal canal contents in patients with mild hand-arm vibration disease and has a certain diagnostic value in nerve damage in patients with hand-arm vibration disease.

Objective: To apply the semi-quantitative risk assessment model in the Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazardous Factors in the Workplace to assess the occupational health risk of electroplating enterprises and explore its applicable conditions and characteristics. Methods: Three electroplating enterprises were selected as the research objects. Occupational hygiene survey and hazard factor detection were conducted on the spot. Three semi-quantitative risk assessment methods were used to assess the risk, and the evaluation results were compared. Results: The consistency between the contact index method and the comprehensive index method was strong. The weighted Kappa value was 0.946 and the P value was less than 0.001, but the consistency between the contact ratio method, the contact index method and the comprehensive index method was poor. The weighted Kappa value was 0.345 and 0.391, and the P value was 0.009 and 0.004, respectively. When the contact concentration is less than 50% OELs, the evaluation results of the contact ratio method are lower than those of the exponential method and the comprehensive exponential method. The consistency of the three methods was the highest when the contact concentration (>50%) and (OELs, the results of the contact ratio method are higher than those of the index method and the comprehensive index method. Conclusion Contact ratio method is suitable for occupational health risk assessment under the condition of incomplete occupational health information and for enterprise managers to identify key control points of health risk through self-assessment; Contact index method is suitable for hazard risk assessment of occupational hazards without sampling test conditions or OELs, and pre-assessment of occupational hazards of construction projects without access to analogical test data. The index method is suitable for occupational health risk assessment with available testing data and complete occupational health information.