Comparison of two risk assessment methods to assess occupational health risk in key industries of dichloromethane in Shenzhen City / 中国职业医学

OBJECTIVE: To compare the applicability of two risk assessment methods to assess the occupational health risk of key industries of dichloromethane in Shenzhen City. METHODS: The Singapore ministry of manpower risk(MOM) method and the comprehensive index method were used to evaluate the risk of 123 positions in 47 key industries of dichloromethane in Shenzhen City. Then the risk classification results of the two assessment methods were compared. RESULTS: The results of MOM method showed that the median and the 0 th to 100 th percentile [M(P_0-P_(100))] of risk of dichloromethane in electronics industry was 2(2-3), and the risk level was low to medium. The M(P_0-P_(100)) of risk of dichloromethane in printing industry was 2(2-4), and the risk level was low to high. The results of the comprehensive index method showed that the M(P_0-P_(100)) of risk of dichloromethane in electronics industry and printing industry were 3(3-4), and the risk level was medium to high. There was no significant difference in the assessment results of occupational health risk of dichloromethane between the electronic industry and the printing industry by MOM evaluation method(P>0.05). The occupational health risk assessment of dichloromethane in printing industry was higher than that in electronic industry by the comprehensive index method(P<0.01). Both evaluation methods were not consistent in the electronics industry and the printing industry(k values were-0.01 and 0.04, all P>0.05). After merging the evaluation results of the two industries, there was no consistency in the evaluation results of the two evaluation methods(k value=0.01, P>0.05). CONCLUSION: The risk level of dichloromethane in printing industry is higher than that in printing industry in Shenzhen City. The comprehensive index method may comprehensively and objectively assess the occupational health risk level of dichloromethane in key industries in Shenzhen City.

P0 protein promotes the expression of INF-γ and IL-10 in peripheral blood of n-hexane neuropathy patients / 中华劳动卫生职业病杂志

Objective@#To study the changes of monocyte cytokines in peripheral blood of n-hexane neuropathy patients induced by P0 protein, and to explore the role of autoimmunity in n-hexane neuropathy patients.@*Methods@#In May 2018, 5 patients with peripheral neuropathy diagnosed as n-hexane poisoning were selected as case group in Shenzhen Prevention and Treatment Center for Occupational Disease in 2017. 6 workers exposure to n-hexane and 6 workers without n-hexane exposure were selected as contact group and control group. Peripheral blood mononuclear cells(PBMC) were isolated from venous blood.@*Results@#The number of spots produced by INF-γ and IL-10 increased after stimulation with P0 protein in case group, and the positive rate was significantly higher than control group and the contact group.@*Conclusion@#Autoimmunity induced by P0 protein may be involved in the occurrence of myelin sheath damage in n-hexane neuropathy patients.

Determination of indium in whole blood by graphite furnace atomic absorption spectrometry / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the sensitization effect of different chemical modifiers in the determination of indium in whole blood by graphite furnace atomic absorption spectrometry, and to develop a new method for the determination of indium in whole blood.</p><p><b>METHODS</b>A mixture of 0.3% HNO3 (V/V) + 0.1% Triton X-100 (V/V) was used as a diluent, and a solution of 1 000 µg/ml Pd (NO3)2 + 3 000 µg/ml Mg (NO3)2 was used as modifier. After being diluted five times, the concentration of indium of the blood was directly determined by graphite furnace atomic absorption spectrometry.</p><p><b>RESULTS</b>The detection limit of the method was 0.33 µg/L, the linear range was 0.33~100.00 µg/L, the relative standard deviation was 1.43%~2.65%, and the recovery rate was 98.3%~105.3%.</p><p><b>CONCLUSION</b>The method is simple and fast and has high recovery and precision, and it is suitable for the determination of indium in whole blood.</p>

Role of poly (ADP-ribose) polymerase 1 in DNA methylation changes induced by hydroquinone in human bronchial epithelial cell / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the DNA methylation changes induced by hydroquinone (HQ) in human bronchial epithelial cells and to explore the role of poly (ADP-ribose) polymerase-l (PARP-l) in this process.</p><p><b>METHODS</b>Human bronchial epithelial 16HBE cells and PARP-l-deficient 16HBE cells (16HBE-shPARP-l cells) were exposed to HQ (10, 20, 40, 60, and 80 µmol/L) for 48h, while control cells were treated with an equal volume of PBS solution. The changes in genomic DNA methylation were investigated by high-performance capillary electrophoresis, and the expression levels of PARP-l and DNA methyltransferase 1 (DNMT1) were measured.</p><p><b>RESULTS</b>The percentages of methylated DNA of overall genome (mCpG%) in 16HBE and 16HBE-shPARP-l cells were 4.89%±0.07% and 9.53%±0.51%, respectively; after treatment with 5-aza-2'-deoxycytidine for 72 h, mCpG% decreased to 3.07±0.12% and 6.34%±0.3%, respectively. The one-way analysis of variance revealed significant differences in mCpG% between the cells exposed to different concentrations of HQ in both 16HBE and 16HBE-shPARP-l groups (F = 61.25, P < 0.01; F = 60.36, P < 0.01). For 16HBE cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-1 were 145.0%, 159.0%, 169.0%, 215.0%, and 236.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); for 16HBE-shPARP-l cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-l were 170.0%, 223.0%, 264.0%, 327.0%, and 320.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all). When the dose of HQ reached 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in 16HBE group were 114.0%, 126.0%, 136.0%, and 162.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); when the dose of HQ reached 10, 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in the 16HBE-shPARP-l group were 141.0%, 165.2%, 186.9%, 202.1%, and 217.3%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all).</p><p><b>CONCLUSION</b>HQ can induce hypomethylation in 16HBE cells, and PARP-1 can regulate DNA methylation in 16HBE cells by influencing the expression and activity of DNMT1.</p>