五种软木尘诱发微核作用的探讨

调查了５种软木接尘工人共５８４人的外周血淋巴细胞微核率，发现均可诱发微核细胞率的增高。以对照组９５％正常上限０．４％作为判断微核阳性的标准，接尘工人的微核阳性率明显高于对照组（Ｐ＜０．０１）。并随工龄的增长而增高，具有明显的剂量、时间—反应关系（ｒ＝０．９０，Ｐ＜０．０１）。五种软木的接尘工人微核阳性率：椴木３６．２％，冷杉２６．３％，白皮松１５．７％，桦木９．６０％，杨木２．１０％。其中椴木和冷杉与对照组相比均有非常显著的差别（Ｐ＜０．０１）。五种软木尘的水提取液均可诱发小鼠骨髓ＰＣＥ微核率的增高，并均有明显的剂量—反应关系，相关系数椴木为０．８６，冷杉为０．６０，白皮松为０．３９，桦木为０．７６，杨木为０．７３；除白皮松Ｐ＜０．０２外，其他４种软木均Ｐ＜０．０１。在１５ｇ／ｋｇ体重剂量下微核率以椴木为最高（０．８０％），依次为冷杉（０．７１％）、桦木（０．６５％）、白皮松（０．６３％）、杨木（０．４３％）。动物试验结果与接尘工人外周血淋巴细胞微核阳性率趋势基本一致。表明软木尘中含有能损伤染色体的物质。

Observation of inducing effect of five kinds of soft wood dust in micronucleus test]

The authors investigated the micronucleus frequencies (MP) in peripheral lymphocytes in 584 workers exposed to five kinds of soft wood dust and found that all kinds of soft wood dust could increase the micronucleus frequency. As the control's 95% confidential upper limit > or = 0.4% is defined as the standard for positivity the micronucleus positive frequency (MPF) in the exposure group is much higher than that in the control group (P < 0.01). Meanwhile the increase of exposure years may increase the MP, and the time-response relationship is evident (r = 0.90, P < 0.01). For different exposures, the MPFs are: 36.2% for linden, 26.3% for fir. 15.7% for lacebark pine, 9.6% for birch and 2.1% for polar. The positive rate of linden and fir exposure are significantly higher than that of the control group (P < 0.01). Water extract of these five kinds of soft wood dust can increase the frequencies of micronucleus in polychromatic red blood cell in mice's sternum marrow, which also showed a dose-response. The correlation coefficients are: 0.86 for linden 0.6 for fir, 0.39 for lacebark pine, 0.76 for birch and 0.73 for polar. All but the lacebark pine have the P value less than 0.01 (P < 0.01). At the dose of 15 g/kg body weight, micronucleus frequency induced by linden was the highest (0.8%), next were fir (0.71%), birch (0.65%), lacebark pine (0.63%), and polar (0.43%). The results from animal test are consistent with those from the exposure workers. These results suggest that there are some substances in soft wood which can induce chromosome aberration.