Modification Of Genetic Susceptibility Factors To Chronic Obstructive Pulmonary Disease In Workers Exposed To Coke Oven Emissions

Coke oven emissions (COE), which mainly enter into human body through respiratory tract, still are one kind of important industrial pollutants in China. Therefore, more attention was paid for the chronic effects on respiratory system after long term and lower level of exposure to COE. Recently, the prevalence of chronic obstructive pulmonary disease (COPD) increase year by year, and COPD is now an important public issue in China. However, there is few report on the relationship between COE exposure and COPD. In order to safeguard worker's health, the risk characterization and dose-response relationships between COPD and COE were explored. A retrospective epidemiological study on 296 coke oven workers (exposure group) and 162 non-exposure workers (control group) was performed. The reference value of lung function was estimated from randomly selected 169 habitants who were non-smoker without dust exposure and lived in the same area as exposure group. It was found that the time weighted average concentration of COE was 7.7 and 2.1 times for workers working at the top or side of oven during 8 hours, compared to the occupational exposure limit (0.1mg/m3) in China and the cumulative exposure index (CEI) of COE significantly increased by working years. There were associations between the abnormal respiratory signs including cough and /or sputum and COPD. The rate of abnormal sputum, cough and sputum, and the prevalence of COPD in exposure group was significantly higher than that in control group, i.e. 16.2% vs. 8.0%, 11.2% vs. 1.2% and 14.5% vs. 5.6%, respectively. After controlling confounders, compared with control group or reference group and analyzed by the non-conditional logistic method, the risk of abnormal sputum was higher than that (OR=2.92-4.01 and OR=5.36, respectively) in whom were less than 53.19 of CEI and more than or equal to 35 years old；Coke oven workers with CEI (1.98 had higher risk in abnormal cough and sputum (OR=13.47-16.97). More than or equal to 1.98 of CEI or ≥300 of smoking index significantly increased the prevalence of COPD (OR=2.40-4.49 and OR=2.75, respectively). Those results implied that exposed to COE and smoking could be the important and independent environmental risk factors of COPD in coke oven workers. Coke oven exposure could be the main effective factors of COPD for lighter or mild smoker (smoking index <300) and, and the cigarette consumption for heavy smokers(smoking index (300).As for the genetic characterization of COPD, a case-only study and matched case-control study were carried out in 52 patients with COPD screened from above study, in order to discover the modification of candidate genetic genes of (1-AT, TNF-(, GSTM1 and GSTT1 in COPD related to COE. In case-only study, it was found that there were modification between TNF-(-308*2 alleles and exposed to COE and between TNF-(-308*2 alleles and GSTM1 null in COPD through analyzed by new 2(2 tables, and its COR was 4.72(95CI: 1.05-21.29) and 4.07(95%CI: 1.08-16.97), respectively. In population based matched case-control study, it was found that the main risk factor of COPD was occupational exposure to COE after controlling the risk factors related to COPD, e.g. smoking, age, etc, and used by matched logistic analysis. The risk of COPD in those with CEI(1.98 was 10.50 times than that in those less than 1.98. Alpha1-AT exon V*Z and TNF-(-308*2 alleles were independent genetic susceptibility factors of COPD (OR=7.31 and OR=4.38, respectively), and had a modification in COPD related to exposed to COE. There was a synergistic effects on COPD between TNF-(-308*2 alleles and GSTM1 null (OR＝6.13). The abnormal respiratory signs were mainly related to the level of exposure to COE. A modification in COPD related to COE was found for those with TNF-308*2 alleles (OR"15). The above results implied that there could be main effective genes or mild effective genes in modification of risk of COPD from COE. The above modification of main effective genes, i.e. (1-AT exon V*Z and TNF-(-308*2 alleles, had stronger. The...