Application of two occupational health risk assessment methods for dust hazards in non-coal underground mines / 环境与职业医学

Background The mining of non-coal underground mines may come into contact with various types of dust, such as lead, zinc, copper, and non-metallic minerals. Dust of various kinds commonly exists in all aspects of mining and selection, and is one of the main occupational hazard groups in non-coal underground mines. Objective To compare the application of two risk assessment methods in the occupational health risk assessment of productive dust in non-coal underground mines, and to provide a reference for the selection of dust hazard health risk assessment methods and the management of dust hazards in non-coal mines. Methods A field investigation of the dust hazards of three typical non-coal underground mining enterprises (lead-zinc mines, copper mines, and fluorite mines) was carried out, and the comprehensive index method and the occupational health risk assessment method from the International Council on Mining and Metals (ICMM) were used to perform risk assessments. The comprehensiveindex method considers the following factors: dust monitoring data, the aerodynamic diameter of dust, hazard control measures, occupational health management, daily usage, and daily exposure time to determine exposure levels. The ICMM method determines the risk level based on the consequences caused by dust, exposure probability, exposure time, and uncertainty coefficient. Kendall consistency test was used to compare agreement between the results generated by the two methods. Results The results generated by the comprehensive index method were as follows: level 3 (medium risk) or level 4 (high risk) for silica dust or lead dust; level 1 (negligible risk) or level 2 (low risk) for other dust (dust with free SiO2 content<10% and containing lead, zinc, and copper, using other dust limit values for comparison), fluorspar mixed dust, fluorine and its compounds, zinc oxide, and copper dust. The risk levels graded by the ICMM method were as follows: level 4 (very high risk) and level 3 (high risk) for exposure to silica dust and lead dust, respectively, and level 1 (tolerable risk) or level 2 (potential risk) for exposure to other dust (dust with free SiO2 content <10% and containing lead, zinc, and copper, using other dust limit values for comparison), fluorspar mixed dust, fluorine and its compounds, zinc oxide, and copper dust. The consistency level between the results graded by the two methods was very high (Kendall W coefficient=0.974, P < 0.05). Conclusion For the occupational health risk assessment of productive dust in non-coal underground mines, the consistency level of risk assessment results between the ICMM method and the comprehensive index method is very high. The ICMM method is more convenient to operate and should be preferred in assessing health risks of dust hazard in non-coal underground mines.

Application and comparison of three occupational health risk assessment methods in automobile manufacturing enterprises / 环境与职业医学

Background The complex and diverse occupational disease hazards in automobile manufacturing industry pose high occupational health risks to workers. Objective To explore the methods that can accurately reflect the workplace health risk grade of automobile manufacturing enterprises, and to guide enterprises to practice risk classification management. Methods Comprehensive index method, International Commission on Mining and Metals occupational health risk assessment method (ICMM method), and risk index method were used toassess health risks of occupational disease hazards in major workstations such as welding, polishing, and painting in three automobile manufacturing enterprises in Hunan Province. Kappa consistency test was used to test the grading results of the three assessment methods. The re-examine results and detection rate of contraindications of occupational health examinations in the past three years were used to verify the assessment results. Results The results of comprehensive index method showed that the hazards of each selected workstation in enterprises A and B were evaluated as grade 2-3, among which NO2 in enterprise A was grade 3, and welding fume, NO2, and formaldehyde in enterprise B were all grade 3. The hazards of each selected workstation in enterprise C were grade 3-4, among which NO2 and benzene in were grade 4, and welding fume, manganese and its compounds, grinding wheel dust, and xylene were grade 3. The hazards evaluated by ICMM quantitative method were grade 2 and grade 5, among which manganese and its compounds in enterprise A and welding fume, grinding wheel dust, and benzene series in enterprise C were graded as grade 5. The hazards evaluated by risk index method were grade 1-4, among which manganese and its compounds in enterprises A and B were grade 3, and manganese and its compounds and benzene in enterprise C were grade 4. The Kappa value between comprehensive index method and ICMM method was 0.084 (P>0.05), that between comprehensive index method and risk index method was −0.046 (P>0.05), and that between ICMM method and risk index method was 0.014 (P>0.05), indicating poor consistency. By comparing the results of occupational health surveillance with the results of occupational health risk assessment, one worker was found to have occupational contraindication of manganese exposure and 1 worker was found to have excessive manganese in hair in enterprise A. However, the comprehensive index method graded low risk for manganese and its compounds in enterprise A and the result is conservative. The key workstations identified by ICMM method were consistent with the occupational health examination results, but the assessment grades were all extremely high risk, and the results were too strict. One worker was found to be contraindicated to welding fumes, and 2 polishers were found to have severe mixed pulmonary ventilation dysfunction in enterprise C. Mild and moderate pulmonary ventilation dysfunction was found to be common in welding and polishing workstations in each enterprise. The assessment results of welding fumes and grinding wheel dust by the risk index method were negligible risks, which were inconsistent with the occupational health examination results. Conclusion The comprehensive index method, ICMM method, and risk index method can basically identify workstations with serious occupational hazards, but they have certain limitations and applicability. In general, the evaluation results of the comprehensive index method were generates more consistent with the results with occupational health surveillance than the other two methods, is more comprehensive and objective in consideration, and is more suitable for health risk assessment of automobile manufacturing enterprises.

Roles of neurovascular unit in cognitive impairment induced by chronic cerebral hypoperfusion / 中华全科医师杂志

Chronic cerebral hypoperfusion (CCH) may result in neurovascular unit (NVU) injury,causing cognitive impairment.The NVU consists of neurons,glial cells,vascular cells and extracellular matrix.The damage of NVU can induce the blood-brain barrier dysfunction,abnormal cell signaling,as well as cognitive impairment.However,its molecular mechanism is unclear.Thus,investigating the role of NUV in CCH-induced cognitive impairment may provide a theoretical basis for the novel treatment of cognitive impairment.

Observations on the Efficacy of Electroacupuncture plus Weak Laser Fat Dissolution Technique in Treating Female Patients with Simple Obesity and Overweight of Stomach Heat Dampness Stagnation Type / 上海针灸杂志

Objective To investigate the clinical efficacy of electroacupuncture plus weak laser fat dissolution technique in treating female patients with obesity and overweight of stomach heat dampness stagnation type. Methods Forty-seven female patients diagnosed with simple obesity and overweight of stomach heat dampness stagnation type were randomly allocated to a treatment group of 25 cases and a control group of 22 cases. The treatment group received electroacupuncture plus weak laser fat dissolution technique and the control group, weak laser fat dissolution technique alone. Body weight, body mass index (BMI), waist circumference, abdominal circumference, hip circumference, body fat percentage (F%), visceral fat index (VFI) were measured in the two groups before and after treatment. The clinical therapeutic effects were compared between the two groups. Results There were statistically significant differences in body weight, BMI, waist circumference, abdominal circumference, hip circumference difference values between before and after one course of treatment, between after one and two courses of treatment and between after two and three courses of treatment in the treatment group compared with the control group (P<0.01,P<0.05). There were statistically significant differences in visceral fat index difference values between after one and two courses of treatment and between after two and three courses of treatment in the treatment group compared with the control group (P<0.05). The total efficacy rate was 92.0%in the treatment group and 36.4%in the control group; there was a statistically significant difference between the two groups (P<0.01). Conclusion Electroacupuncture plus weak laser fat dissolution technique is an effective way to treat female simple obesity of stomach heat dampness stagnation type.

Effect of epidural block on tissue structure of prolapsed intervertebral disc and yellow ligament / 中国组织工程研究

BACKGROUND: Epidural block(EB) is one of the effective and widely used remedies for lumbar disc herniation(LDH) . Animal experiments have been conducted to study the changes in the local tissue structure in the spinal canel after several treatments with EB.OBJECTIVE: To study the effect of EB for LDH on the local tissue structures in the spinal canel.DESIGN: A non-randomized and controlled clinical observation.PARTICIPANTS: Department of Pathology and Laboratory of Electron Microscope of an Affiliated Hospital of a University.SUBJECTS: Forty patients with LDP, who failed to respond to EB treatment and subsequently received discectomy in the Department of Orthopaedics,First Affiliated Hospital of Sun Yat-sen University from May 1992 to December 1997, were enrolled in this study, with 20 patients receiving discectomy but not EB treatment serving as the control group.METHODS: From the 60 cases, totally 120 specimens of yellow ligament and the disc tissues were obtained during discectomy for optical microscopical examination. A portion of the yellow ligament and the lumbar disc tissues were chosen from EB group(12 cases) and non-EB group(10 cases), respectively, for electron microscope examination(involving altogether 44specimens) . The changes in histology and ultrastructnres in the specimens were compared between the two groups.MAIN OUTCOME MEASURES: ① Main results: the reactive proliferation of the tunica adventitia and inflammatory reaction of the intervertebral disc and yellow ligament; ② Secondary results: changes in the ultrastructure of the anulus fibrosus, nucleus pulposus and yellow ligament.RESULTS: No significant difference was found between the two groups either in light microscopy or electron microscopy in the degree of smoothness and the inflammatory reaction of the cavosurface of the yellow ligament and the disc tissues, nor in the cellular ultrastructures and fibrous arrangement.CONCLUSION: There is no direct relationship between lumbar EB and epidural scar adhesion formation. EB does not affect the ultrastructures of the local tissues in the spinal canal, but care must be taken of the sterilization in the surgical procedure, as chronic inflammatory reaction in the yellow ligament and disc tissues can be present in some patients.

The Effects of Asiaticoside on Fibroblasts in vitro Culture / 中山大学学报(医学科学版)

【Objective】 To investigate the possible mechanism of the asiaticoside used for the treatment of hypertrophic scar. 【Method】 Using microscope, electron microscope, MTT test, 3　H-TdR and 3　H-Pro line incorpo ration to study the effect of the asiaticoside on DNA synthesis and collagen bi osynthesis of fibroblast in vitro culture. 【Results】 The asiaticoside not only affected the ultrostructure of fibroblast, but also inhibted the DNA synthesis a nd collagen biosynthesis.【Conclusion】 Asiaticoside can play an important role in the prevntion and treatment of scars, the mechanism may be that the asiaticos ide can inhibted the DNA synthesis and collagen biosynthesis of fibroblast.

Analysis of the Antigens of Vibrio cholerae with Monoclonal Antibody / 第二军医大学学报

In this paper, the antigens of both Vibrio cholerae on 55 strains of El Tor and on 28 strains obtained with genetical method were studied by ELISA method using 12 strains of McAb against Vibrio cholerae (VCOMcAb). The results indicated that the 55 strains of Vibrio cholerae El Tor were expressed 11(A-K) of the recognized antigenic determinants, and fell into XⅧ(Ⅰ-XⅧ) distinct McAb reactivity types or groups, and the 28 varients of Vibrio cholerae from genetical method were expressed 9 (A-Ⅰ) of the recognized antigenic determinants, and fell into Ⅹ (Ⅰ-Ⅹ) distinct McAb reactivity types or groups. From those VCOMcAbs, the “F3” could recognize all 55 strains of Vibrio cholerae El Tor, indicating it has specificity; other 11 strains of VCOMcAb have a variety of reactivity to antigens on the 55 strains of Vibrio cholerae El Tor in both Inaba and Ogawa and their percentages of reactivity are different. This shows that these strains may have subtypes or subgroups.