长期低浓度苯接触的遗传损伤作用

［目的］ 探讨长期低浓度苯接触的遗传损伤作用。 ［方法］ 采用气相色谱法检测和评价工作场所空气中苯浓度；对苯接触组116 人和对照组62 人进行血常规检测、外周血淋巴细胞染色体畸变分析以及微核率检测。 ［结果］工作场所空气中苯浓度为〈0.033~1.898 mg/m3，低于我国苯职业接触限值［时间加权平均容许浓度（PC-TWA）=6 mg/m3；短时间接触容许浓度（PC-STEL）=10 mg/m3）］。苯接触组白细胞计数为（4.70±1.02）×109/L，低于对照组的白细胞计数（6.58±1.61）×109/L，差异有统计学意义（P 〈 0.01），且与苯接触工龄呈负相关（r=-0.993，P 〈 0.01）；苯接触组和对照组染色体畸变率分别为（0.58±0.88）%和（0.13±0.42）%，微核率分别为（4.03±3.31）‰和（2.00±2.00）‰，该两项指标在苯接触组和对照组之间的差异均有统计学意义（P 〈 0.05），且均与苯接触工龄呈正相关（r=0.289、0.616，P 〈 0.01），与白细胞计数呈负相关（r=-0.306、-0.645，P 〈 0.01）。 ［结论］ 长期低浓度苯接触可造成细胞遗传损伤。

Genetic Damage by Long-Term Exposure to Low Concentrations of Benzene

Objective] To investigate the genetic damage of long-term low concentrations of benzene exposure. Methods]The air concentrations of benzene at workplaces were measured and evaluated by gas chromatography. Blood routine test, chromosome aberration, and micronucleus assay of peripheral blood lymphocyte in an exposed group （n=116） and a control group （n=62） were performed. Results] The air concentrations of benzene in the selected workplace were 〈0.033-1.898 mg/m3, lower than the national occupational exposure limit of benzene （permissible concentration-time weighted average, PC-TWA=6 mg/m3; permissible concentration-short term exposure limit, PC-STEL=10 mg/m3）. The average white blood cell （WBC） count in the exposed group was （4.70±1.02）×109/L, lower than that of the control group（6.58±1.61）×109/L]（P 〈 0.01）, and also negatively correlated with length of service （r=-0.993, P 〈 0.01）. The chromosomal aberration rates in the exposed group and the control group were （0.58±0.88）% and （0.13±0.42）%, respectively, and the micronucleus rates were （4.03±3.31）‰ and （2.00±2.00）‰ , respectively. Both rates showed significant differences （P 〈 0.05）, and were positively correlated with length of service （r=0.289, 0.616, P 〈 0.01） and negatively correlated with WBC count （r=-0.306, -0.645, P 〈 0.01）. Conclusion] Long-term exposure to low concentrations of benzene at work can cause cytogenetic damage effect in exposed workers.