不同粒径大气颗粒物几种重金属成分分析及其致突变性研究

Study of the Genotoxicity and Concentration of Five Metals in Air- Borne Particles.

采集冬季太原市一采样点不同粒径大气颗粒物,经分析,总悬浮颗粒物日均浓度为1.04mg/m^3,严重超标。其中粒径小于7.0μm的占49.6％,小于3.3μm的占33.5％。颗粒物无机提取液中5种金属元素的浓度由高到低依次为Pb、Mn、Cr、Ni和Cd。每一种元素均呈随颗粒物粒径减小浓度增高的趋势。以SOS显色法和小鼠体内骨髓细胞染色体畸变试验检测颗粒物的无机提取液和模拟肺泡液溶出液的遗传毒性,表明小粒径颗粒物遗传毒性较强;小于1.1μm的颗粒物,仅用相当于5m^3或10m^3空气量的样品液,即可诱发SOS反应或致染色体损伤。

Samples of variously- sized total suspended particulates (TSP) in the air of one sampling site of Taiyuan are collected in winter. The concentration and the percentage of the particulates are measured, five metals including Pb, Mn, Cr, Ni and Cd in the extracts from the samples are quantitatively analyzed by atomic absorption spectrometer, and the genotoxicity of the extracts are detected by the SOS chromotest and the mouse bone marrow cellular chromosome aberration assay in vivo. The results show that the mean concentration of TSP is 1. 04mg/m3, much higher than the National Standard. The pollution of the smaller- sized particles is serious, as nearly half of the particles are less than 7. 0μm in diameter. The concentration of Pb, Mn and Ni are high. Besides, the metals can be enriched strongly on the surface of the small particles. Having extracted by simulated lung fluid (SLF), it has been found that metals can dissolve partialy into the SLF. The experiments show that both the extracts of acid and that of SLF of the smaller sized particles can induce SOS response and cause an increase in chromosomal aberrations. This indicates the existence of genotoxjcants which may cause DNA damage or have clastogenic effects in the smaller-sized particles.