中文摘要：

为了了解风沙季节的颗粒物浓度特征，特别是在风沙天气来临前后颗粒物浓度的变化，2002年春季分别在北京的延庆和观象台进行了连续的颗粒物观测，并对观测资料进行了较为详细的统计分析。结果表明：在风沙季节，沙尘天气出现前后的颗粒物浓度变化幅度非常显著，对环境质量的影响明显增大；TSP与PM10，PM10与PM2．5的相关性非常显著，线性关系好。沙尘天气对不同粒径颗粒物浓度贡献的增加在33％～86％之间。

英文摘要：

In order to understand the concentration characteristics of PM （Particulate Matter） in sandstorm season, PM concentrations were observed in the spring of 2002. The observational results show that the concentrations of PM were lower in the periods without sandstorms than those with sandstorms. During sandstorms, the air quality became very poor. The results also show that there are significant linear correlation between PM10 and TSP, PM10 and PM2.5 concentrations. The added contribution of sandstorm weather to the vari-sized PM concentrations is about 33 % to 86 %.