【摘要】 目的研究北京市大气颗粒物中提取的多环芳烃组分的致突变性,并探讨采样点、粒径、季节对多环芳烃致突变活性的影响。方法于2005年7和12月从北京市工业区和商业区冬夏两季采集的可吸入颗粒物(PM10和PM2.5)样本中提取出多环芳烃。采用Ames试验检测该多环芳烃的致突变性。每个多环芳烃样本各设125、250和500μg/皿3个剂量,在加S9和不加S9条件下进行实验。结果受试多环芳烃组分在加S9和不加S9条件下均可引起TA98菌株发生回复突变增加,而且在加入活化系统S9后工业区样本的突变活性明显增加。随剂量增加,突变率升高,除部分低、中浓度组外,其他组的每皿回变菌落数为阴性对照的2倍或2倍以上;各组均存在明显的剂量-反应关系(P<0.01,P<0.05)。工业区多环芳烃样本的回变菌落数均高于商业区。冬季多环芳烃样本诱导的回变菌落数高于夏季样本。同剂量的PM2.5的多环芳烃样本诱导TA98菌株产生的回变菌落数大于PM10的多环芳烃样本。结论多环芳烃样本具有较强的致突变性并且以移码型突变为主。工业区多环芳烃样本主要是间接致突变物。工业区空气样本的多环芳烃组分的致突变性明显高于商业区。同剂量的PM2.5的多环芳烃组分的致突变性大于PM10。冬季颗粒物的多环芳烃组分的致突变性均比夏季组分致突变性强,并且商业区冬夏两季致突变性差异较工业区明显。更多还原

【Abstract】 Objective To assess the mutagenicity of polycyclic aromatic hydrocarbons(PAHs) extracted from the atmospheric particulates collected from different aerodynamic sizes,seasonal variation and the sampled sites,and to detect the effect of these factors on the mutagenic activity of PAHs.Methods PAHs were extracted from the atmospheric particulates(PM10 and PM2.5) collected from two different sites,business area and industrial area(summer and winter respectively).The mutagenicity of these PAHs samples was evaluated by the Salmonella mutagenicity assay(Ames assay),using Salmonella typhimurium strains TA98 and TA100 with and without metabolic activation(S9).Each sample was assayed in three doses(125,250 and 500μg per plate).Results All samples induced the number of revertants to be higher measured with TA98 with and without S9 mix.The level of specific mutagenic activity measured with strain TA98 was higher than TA100.Metabolic activation with the S9 fraction increased the mutagenicity of the industrial area samples studied for the strain TA98.All groups showed a good dose-response relationship of mutagenicity(P<0.01 or P<0.05).The number of revertants induced by samples from industrial area was higher than that from business area.And also the number of revertants induced by all samples collected from winter was higher than that from summer. The number of revertants induced by samples from PM2.5 was higher than that from PM10 with stain TA98 at the same dose. Conclusion All samples showed mutagenicity with strain TA98.The mechanism of mutagenicity of PAHs was a frame-shift mutation and PAHs from industrial area mostly were indirect-acting mutagens.The mutagenicity of PAHs collected in industrial area is much higher than that in business area;and the results also indicate that PAHs extracted from PM2.5 has higher mutagenicity than those extracted from PM10;a seasonal variation of mutagenicity was observed with higher mutagenic activity in winter,and the mutagenic activity difference between winter and summer from two sampled sites was also observed.更多还原