道路扬尘毒性研究

Toxicity of Raised Dust From Streets

目的 探讨道路扬尘的肺细胞毒性和致突变性。方法 采集哈尔滨市A街（柏油路面）扬尘制成5％混悬液,选择WK大鼠随机分为4组,每组10只,按0.5 ml/100g体重,经气管一次染毒,分别在染毒后24h、4d及30d进行肺灌洗液肺巨噬细胞计数和细胞分类计数,并测定乳酸脱氢酶（LDH）和酸性磷酸酶（ACP）活力。同时采集A街和B路（土路）扬尘,对其有机提取物进行Ames试验。结果 染毒4d肺灌洗液巨噬细胞数与对照组比较显著减少（P<0.01）,染毒24h～30d LDH和ACP活力显著高于对照组（P<0.05）,A街扬尘有机提取物对TA98-S9和TA100-S9致突变阳性,B路扬尘有机提取物对TA98-S9致突变阳性。结论 哈尔滨市街道扬尘可造成大鼠肺及支气管组织损伤,并具有致突变性。

Objective To explore the cytotoxicity and rnutagcnecity of raised dust from the streets. Methods Raised dust was sampled from A street (asphalt road) of Harbin for preparation of raised-dust suspension with concentration of 5%. The WK rats were randomly divided into 4 groups, 10 rats per group. The rats were exposed to raised-dust suspension by direct intratracheal injection method for one time according to the dose of 0.5 ml per 100 g of body weight. At the 24th hour, the 4th day and the 30th day after the exposure, the amount of macrophagcs and the differentiation of cells in pulmonary lavage fluid were counted, the activities of lactic dehydrogenase (LDH) and acid phosphatase (ACP) in pulmonary lavage fluid were determined. The mutagenicity of the organic extracts of raised dust from A street and B road (dirt road) was detected by Ames test without the activation of S9 mixture. Results Significant decrease of the count of macrophages in pulmonary lavage fluid was found in rats at the 4th day after exposure to raised-dust suspension compared with that of control group (P<0.01) . The activities of LUH and ACP in pulmonary purfusate from rats exposed to raised-dust suspension were significantly higher than those in control group during the 24th hour to the 30th day after exposure to raised-dust suspension (P<0.05). Positive result was observed in Ames test on mutagenicity of the organic extracts of raised dust from A street with strains of TA98 and TA100 without the activation of 89 mixture, it was also observed in mutagenicity of the organic extracts of raised-dust from B road with strain of TA98 without the activation of Sv mixture. Conclusion The raised dust from the street of Harbin could impair the lung tissue and (he bronchial tissue, its organic extract also revealed mutagenicity.