兰州市西固城区街道灰尘粒径特征及环境效应分析

Assessment for Particle Size Distribution and Associated Environment Effects for Street Dust in Xigu District of Lanzhou,Shanxi Province

分析研究了兰州市西固城区街道灰尘的粒径组成、分配规律及环境效应。结果表明:(1)研究区92.21%的街道灰尘为细粒子(<0.25mm),不低于45%的街道灰尘可能是通过高空悬移搬运而来,受远程源的沉降影响较大。(2)除商业点外,各功能点与对照点的粒径质量组成的变化趋势基本一致:粉黏粒>极细砂>细砂>粗中砂,对人体健康影响较大的粉黏粒呈现出如下分配趋势:住宅点>交通点>工业点>商业点。(3)65%～75%的街道灰尘极易在相对封闭的空间内再悬浮,成为城市扬尘污染和影响居民健康的一个自身潜在源。

The author investigated characteristics, environment effects for particle size distribution of street dust, in Xigu region of Lanzhou city. The paper concludes with major results as follows： （1） 92.21% of dusts took the form of petty size, which regarded as lesser than 0.25 mm in diameter ; street dust and its characteristics were greatly impacted by emission sources far away from studied areas, more than 45 % of dust proved to be transported through long distance from other areas; （2） except for commercial area, the particles of street dust in other city function are- as share similar composition. The largest component of street dust proved to he the power or clay, and followed hy petty sand, rough sand. ;（3） As for health effects associated with dust street lesser than 0. 043 mm in various func- tional areas, residential areas under most servere impact, followed by traffic areas, industrial areas and commercial areas; （4） approximately 65 % to 75%of street dust is likely to float in the air, which therefore become potential source for air pollution and may impact residents health in the studied areas.