This article investigated an occupational chemical poisoning incident that occurred in a certain place in Guangdong Province in September 2020, detected the air at the scene, and analyzed the clinical data of the poisoned patients. The peripheral blood methanol concentrations of the three patients were 307.76 mg/L, 354.80 mg/L and 454.14 mg/L when they were admitted to the hospital. The raw and auxiliary materials were analyzed for volatile organic components. Methyl acetate was detected in the finished glue, synthetic resin and compound machine post glue in the glue room, and the relative percentages were 23.05%, 32.79% and 31.68%, respectively. Through comprehensive analysis, it was judged that this incident was an acute occupational methyl acetate poisoning incident, and 3 workers were poisoned.

This article investigated an occupational chemical poisoning incident that occurred in a certain place in Guangdong Province in September 2020, detected the air at the scene, and analyzed the clinical data of the poisoned patients. The peripheral blood methanol concentrations of the three patients were 307.76 mg/L, 354.80 mg/L and 454.14 mg/L when they were admitted to the hospital. The raw and auxiliary materials were analyzed for volatile organic components. Methyl acetate was detected in the finished glue, synthetic resin and compound machine post glue in the glue room, and the relative percentages were 23.05%, 32.79% and 31.68%, respectively. Through comprehensive analysis, it was judged that this incident was an acute occupational methyl acetate poisoning incident, and 3 workers were poisoned.

Objective To investigate the in vivo stress distribution of the atherosclerotic plaque at carotid bifurcation, so as to provide references for the mechanical mechanisms of plaque rupture at carotid bifurcation and the design for further medical treatment. Methods The three-dimensional geometric model of carotid bifurcation and plaque were established according to average geometric parameters of human carotid bifurcation. Residual stress of the carotid bifurcation and plague was reestablished with “thermal-structure” coupling method, and in vivo stresses of vessels with the plaque at carotid bifurcation under blood pressure and blood flow were calculated. Results Both the maximum principal stress and elastic shear stress concentrated on the shoulder of the plaque. Elastic shear stress increased with the increase of stenosis ratio and blood pressure. Wall shear stress in the upstream of the plaque was considerably higher than that of the downstream. The distribution of oscillatory shear index(OSI) was quite the opposite. The changing patterns of the elastic shear stress and flow shear stress were quite different with the change of stenosis ratios. Conclusions Tension grew gradually from the centrality to shoulder surface of the plaque. The centrality of the plaque might bear compression when the stenosis was very severe. The periodic variation of the structural stress might cause structural fatigue of the plaque, thus increasing the rupture risk. Distinction of the component and vulnerability of the plaque between upstream and downstream might be caused by differences in hemodynamic parameters of the plaque between upstream and downstream.

Objective: To explore the applicability of semi-quantitative risk assessment methods in wood furniture manufacturing companies. Methods: Two medium-sized wooden furniture manufactures were randomly selected as research objects, namely A company and B company. Used the Semi-Quantitative risk assessment method (the ratio method, the index method and the comprehensive method) in the "Guidelines for occupational health risk assessment of chemicals in the workplace" (GBZ/T 298-2017) to conduct occupational hygiene survey, occupational hazard factor testing and occupational health risk assessments for two wood furniture manufacturers from January to October 2018, and compared and analyzed the applicability of these three semi-quantitative risk assessment methods in wooden furniture manufacturing enterprises. Results: The occupational health status of A enterprises was worse than that of B enterprises, and the occupational health risk level was higher than that of B enterprises, and the risk level of A enterprise is 3~4, and the risk level of B enterprise is 2~3. The occupational health risk level obtained by the index method was consistent with the comprehensive method, while the risk level of some occupational disease hazards used the ratio method was inconsistent with the results of the index method and the comprehensive method. Compared with the index method and the comprehensive method, when E/OEL<0.5 or E/OEL≥2, there might be a certain fluctuation in the occupational health risk level obtained by the ratio method. Conclusion The semi-quantitative risk assessment is more objective, comprehensive and flexible in the application of occupational health risk assessment, and can assess the occupational health risk level of chemical poisons in wood furniture manufacturing enterprises.

Objective: To explore the applicability of Singapore semi-quantitative assessment method and international committee on mining and metals occupational health risk assessment method in occupational health risk assessment of ceramic enterprises. Methods: From March 2017 to May 2018, A ceramic enterprise was selected for the investigation and testing of occupational health, and the risk assessment of the occupational-disease-inductive factors in the workplace was conducted by the semi-quantitative assessment method of Singapore and the occupational health risk assessment method of the international committee on mining and metals. Results: The occupational-disease-inductive factors in the production process of this ceramic enterprise mainly include silicon dust, noise, high temperature, carbon monoxide, carbon dioxide and so on. The two risk assessment methods were applied to assess the risk of occupational-disease-inductive factors in the workplace, and the results showed that the high risk level was 16.67%, the medium risk level was 63.33%, and the low risk level was 20.00%. The risk level of silicon dust is from low risk to high risk. Conclusion The semi-quantitative assessment method and the occupational health risk assessment method of the International Commission on Mining and Metals are simple to operate and practical, and are suitable for the assessment of occupational hazards in ceramic enterprises.

OBJECTIVE: To explore the applicability of Singapore Ministry of Manpower( MOM) risk model and MES model in risk assessment of occupational health hazard caused by chemical poisons in shoemaking enterprises. METHODS: A medium-sized shoemaking enterprise in Guangzhou City was selected as the research object to carry out on-the-spot investigation of occupational health,measure the level of chemical hazards in the air of the workplace. Occupational health risk assessment of chemical toxins in the workplace was conducted using the MOM model and the MES model,and the results of the two evaluations were compared. RESULTS: The occupational chemical hazards in workplace of the shoemaking enterprise mainly included the toluene,xylene,ethyl acetate,butyl acetate,n-hexane,and 1,2-dichloroethan( 1,2-DCE). The concentration-time weighted average( CTWA) of 1,2-DCE at the stitching post,methylbenzene at the brush coating post and ethyl acetate at the cleaning post exceeded occupational exposure limits. The MOM model assessment results showed that methylbenzene was of high risk and 1,2-DCE was of medium risk in brush coating post. n-Hexane and1,2-DCE were of medium risk in stitching post. Ethyl acetate and 1,2-DCE was of medium risk in cleaning post. The results of the MES model evaluation showed that the risk level of n-hexane and 1,2-DCE used in sticking,brush coating and cleaning posts was extremely high and the remaining chemicals were highly dangerous. CONCLUSION: Both MOM model and MES model can easily predict and assess the occupational health risk of various posts in shoemaking enterprises to some extent. The assessment result of MES model is more practical than that of MOM model.

Objective: A solvent desorption-gas chromatography method for determination of ethylal in workplace air has been established. Methods: Ethylal in workplace air was collected by activated carbon tube and desorbed with carbon disulfide, and the desorption solutions were analysed by capillary column GC with FID detector. Results: The method presented a good linearity in the range of 0.87~34 800.00 mg/L of ethylal in the standard solution, with the correlation coefficient being r=0.999 7. The limit of detection and the limit of quantification of this method were respectively 0.20 mg/L and 0.80 mg/L, and the minimum detectable concentration and the minimum quantification concentration of this method were respectively 0.17 mg/m³ and 0.60 mg/m³ per 1.50 L of air.The within-run precision of the method was 2.93%-6.20%, and the between-run precision 3.67%-6.44%. The desorption efficiency between 94.22%-97.27%. Ethylal in activated carbon tube could be kept at least 7 days at room temperature without significant loss. Conclusion The method could be used for determination of ethylal in workplace air.

Objective To investigate the efficacy and safety of three injections fat soluble drugs to dissolve fat.Methods 3T3-L1 preadipocytes were treated with 5％ phosphatidyl choline (PC),4.5％ deoxycholate salts (DC) and lipostabil,respectively; thiazolyl tetrazolium (MTT) method was used to measure the different fat cell proliferation activity,the enzyme assay to measure liquid triglyceride (TG) content in culture media and to evaluate the degree of dissolution of the fat cells.16 Hartley white guinea pigs were randomly divided into four groups:shoulder (group a),scapular region (group b),hips (group c),and back (control group) were injected with fat soluble drug 0.5 ml in different parts of the guinea pig fat layer,and at different time points tissues were cut for pathological analysis.Results The proliferative activity of 3T3-L1 preadipocytes were significantly decreased after treatment with three types of fat soluble drugs compared with control group (P＜0.05),and their effects on dissolution of fat cells were also significant:the contents were 5％ PC (4.14±0.92)mmol/L,4.5％ DC (3.91 ±0.67) mmol/L,and lipostabil (4.23± 0.76) mmol/L,respectively,which were significantly higher than that of the control (1.91±0.12) mmol/L (P＜0.05); guinea pigs in vivo showed that the three types of fat soluble drugs on dissolving adipose tissue at the injection site had varying degrees of swelling,lymphocytic infiltration,and fat cell degeneration,fusion and decrease in number.Conclusions Three fat soluble injections could dissolve the fat cells in some degree,in whichi lipostabil is stronger than other fat soluble drugs,but their effect on adipose tissue is nonspecific,and therefore clinical application of those fat soluble drugs should be in high caution.

OBJECTIVETo analyze the risk factors of nonspecific low back pain in community populations.

METHODSTwo community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model.

RESULTSA total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060).

CONCLUSIONGender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.

Objective To analyze the risk factors of nonspecific low back pain in community populations. Methods Two community populations were investigated using questionnaires in this case-control study. The questionnaire was designed to collect data including age, gender, body weight, marriage, education, income, occupation, labor intensity, smoking, alcohol drinking and social mental status. The subjects with low back pain constituted the case group and those without low back pain served as the control group, and the data was analyzed by a Logistic regression model. Results A total of 1747 community residents participated in this survey, among whom 398 subjects had low back pain and 1126 subjects without low back pain were selected as the control group. Of all the latent risk factors of low back pain in Logistic regression model, gender was the most relevant factor (OR=3.5522) followed by education (OR=1.958), labor intensity (OR=1.956), marital status (OR=1.612), vibration source exposure (OR=1.491), BMI (OR=1.127) and age (OR=1.060). Conclusion Gender, education, labor intensity, marriage, vibration source exposure and BMI are risk factors of nonspecific low back pain in community populations, and exercises and mental status can be protective factors against low back pain.