Study On The Correlation Between Exposure To Occupational Chromium And Methylation Of P16 Gene In Peripheral Blood

Objective:This study through the survey of iron and steel workers occupational history,chromium exposure dose and workers outside the working environment within the exposure dose measurement and detection of P16 gene DNA methylation status,chromium to explore occupational exposure of P16 gene methylation status,analysis of chromium exposed impact on downstream of P16 gene protein expression levels,provide a basis for the study of the toxicity mechanism of chromium;Explore the chromium steel workers exposed the influence factors of P16 gene methylation,provide theoretical basis for occupational protection and health management.Method:This study choose some iron and steel group company male stainless steel workers 216 people as exposed group,including the furnaceman 67 people,JiaoGangGong 52 people and Lian ZhuGong 97 people,the corresponding work environment respectively for steelmaking workshop,casting workshop and casting steel workshop;Choose male boiler worker 121 people as control group,the corresponding working conditions for the boiler workshop.The objects of study in recent 3 months there are no history of antitumor drug taking and exposure to ionizing radiation.With reference to "harmful substances in the workplace air monitoring sampling rules"(GBZ159-2004)and "workplace air toxic substances determination"(GBZ/T160-2004)to workers in the workplaces where monitoring sampling;Using uniform design epidemiological investigation questionnaire on the object of study;Extract workers 3 ml heparin anticoagulation venous blood,3 ml of anticoagulant venous blood.Application of Graphite furnace atomic absorption spectrometry detect chromium and its compounds in steelmaking professional environment concentration and steel workers and control group of serum chromium content;Whole blood extract DNA,by Methylation Specific PCR method amplification and determination of P16 gene Methylation status;Using enzyme-linked immunosorbent method to detect serum 8-hydroxy deoxyguanosine(8-OHdG)?Malondialdehyde(MDA)and Glutathione(GSH)and P16 protein content.For classification variables to test,t-test and variance analysis was carried out on the continuity than variables,the analysis of the type of work,shift,length of service,smoking,drinking the P16 gene methylation of occupational chromium exposed workers and the effect of using unconditioned logistic regression analysis of the related to many factors.Result: 1.The test results of chromium internal and external exposureExposed group steelmaking workshop,casting workshop,casting steel smelting workshop with controls boiler workshop exposure concentration of chromium and its compounds as t test,the results each workshop concentration of chromium and its compounds are exposed group were higher than that of control group,difference has statistical significance(P<0.05).Compare chromium exposed group blood chromium exposure dose and the control group in blood chromium exposure dose,the former is obviously higher than that of the latter,statistically significant difference(P<0.001).Exposed concrete according to the type of work are divided into groups and casting steel cast steel cast,Lian ZhuGong group,combined with the control group in the boiler workshop group;For analysis of variance between groups of serum chromium content found that blood chrome content differences between four groups have statistical significance(P<0.001).Further the LSD-t test compares the two two of four groups of people,differences were statistically significant(P>0.05).2.The comparison of peripheral blood P16 gene methylation rate and P16 protein expression levelsBy the chi-square test,peripheral blood P16 gene methylation rate of exposed group was obviously higher than that of control group,the difference was statistically significant(P<0.001);By wilcoxon rank and inspection exposed group serum P16 protein expression levels lower than the control group,difference has statistical significance(P<0.024);T-test showed that exposed group 8-OHdG content is higher than the control group,difference has statistical significance(P=0.012);Exposed group of GSH content is lower than the control group,the difference was statistically significant(P=0.028);MDA content differences between exposure group and control group with no statistical significance(P>0.05).Spearman rank correlation analysis results showed between peripheral blood P16 gene methylation and 8-OHdG?MDA? GSH content was no significant correlation(P=0.492?0.710 and 0.085).3.Analysis influence factors of peripheral blood P16 gene methylation occupational chromium exposure populationBy LSD-t test,steel worker,LianZhuGong and JiaoGangGong the peripheral blood of P16 gene methylation rate difference was statistically significant(P<0.001);The peripheral blood of P16 gene methylation rate in shift work group is significantly higher than the long white team,statistically significant difference(P<0.001);Exposure population grouping according to the length of service,30~38 year age workers peripheral blood P16 gene methylation rate is the highest(80.5%),with the increase of the length of peripheral blood P16 gene methylation rate showed a trend of increase,the age difference statistically significant(2ctrend=9.018,P=9.018);In exposed people,the Peripheral blood P16 gene methylation rate differences berween smoking group and non-smoking group had no statistical significance(P>0.05);Drinking group and non-drinking group peripheral blood P16 gene methylation rate also no statistically significant difference(P>0.05);Unconditioned logistic regression analysis showed that: high blood concentration of chromium(OR=1.956,95%CI:1.285~2.977)and shift work(OR=2.408,95%CI:1.795~5.828)are risk factors for workers peripheral blood the of P16 gene methylation exposed occupational chromium.Conclusion:1.The concentrations of chromium and its compounds in stainless steel smelting workshop air are significantly higher than the boiler workshop,but not more than the national occupational health standards(0.05 mg/m3).The chromium content in stainless steel smelting workers peripheral blood(4.15ug/L)is significantly higher than control group(1.56ug/L).2.Occupational chromium exposure population peripheral blood P16 gene methylation rate is higher than control group.3.High chromium content in serum and shift work are risk factors for occupationnal chromium exposed workers peripheral blood the of P16 gene methylation.