广州市交通警察淋巴细胞DNA损伤的研究

目的研究交通警察的职业暴露与吸烟对淋巴细胞DNA损伤的影响.方法研究对象为广州市8个区的交通警共812人(男741人、女71人,其中内勤130人、外勤682人).静脉取血,以淋巴细胞分离液分离淋巴细胞.以彗星电泳的方法测定淋巴细胞DNA的损伤.结果未经校正的结果表明,内勤警平均年龄[(37.7±9.5)岁]较外勤警[(32.3±8.1)岁]大,且差异有显著性(P＜0.01).性别(P=0.08)与年龄(P=0.45)对DNA损伤无影响.外勤警淋巴细胞彗星尾矩为4.20μm,95%CI为3.98～4.42μm,内勤警为3.23μm,95%CI为2.82～3.70μm,表明外勤警的DNA损伤较内勤警为重,差异有显著性(P＜0.01).吸烟者淋巴细胞彗星尾矩为4.66μm,95%CI为4.37～4.97μm,不吸烟者为3.47μm,95%CI为3.21～3.75μm,而戒烟者则为3.28(2.57～4.17)μm,表明吸烟者的DNA损伤较戒烟者和不吸烟者为重,差异有显著性(P＜0.01).在非吸烟者中,仅在家中的被动吸烟可使DNA损伤增加,但如果将外勤警除外,则工作场所的被动吸烟也可使DNA损伤增加.以协方差分析调整了各因素的影响,发现外勤警的职业、吸烟与女性性别可使淋巴细胞DNA损伤增加,且差异均有显著性(P＜0.01).未发现年龄与被动吸烟对DNA损伤有影响.结论交通警的职业暴露与吸烟可使DNA损伤增加,女性交通警较男性交通警DNA损伤为重.

A study on lymphocyte DNA damage in traffic policemen in Guangzhou

OBJECTIVE: To study the effect of occupational exposure to traffic exhaust and smoking on DNA damage in traffic policemen. METHODS: 812 traffic policemen (741 men and 71 women, 130 of office-work and 682 of outside work) from 8 districts in Guangzhou were investigated. Blood samples were taken by venipuncture and lymphocytes were collected by using lymphocyte separation medium and centrifugation. The comet assay was used to measure DNA damage. RESULTS: The office-work policemen [(37.7 +/- 9.5) years] were older than the outside-work ones [(32.3 +/- 8.1) years, P < 0.001]. No significant difference was observed in sex (P = 0.08) and age (P = 0.45). Comet assay showed that occupational exposure to traffic exhaust significantly increased tail length [4.20 micro m, 95% CI: (3.98 - 4.42) micro m vs 3.23 micro m, 95% CI: (2.82 - 3.7) micro m, P < 0.001]. Smokers had longer tail length [4.66 micro m, 95% CI: (4.37 - 4.97) micro m] than ex-smokers [3.28 micro m, 95% CI: (2.57 - 4.17) micro m] and nonsmokers [3.47 micro m, 95% CI: (3.21 - 3.75) micro m, P < 0.001]. In nonsmokers, significant increase in tail length was observed by passive smoking at home (P = 0.004) but not at work (P = 0.22). When out-door nonsmokers were excluded, passive smoking at work also significantly increased tail length (P = 0.007). Analysis of covariance showed that occupational exposure to traffic exhaust, tobacco smoking, and female had independent effect on lymphocyte DNA damage (P < 0.001) after these factors were adjusted. Passive smoking and age had no effect on lymphocyte DNA damage. CONCLUSIONS: Occupational exposure to traffic exhaust and tobacco smoking respectively increase lymphocyte DNA damage. Female traffic policemen may have more severe DNA damage than male.