The impacts of different kinds of dust events on PM 10 pollution in northern China

Abstract

In this study the frequencies of PM 10 (as key urban pollutant) in 14 key environmental protection cities in northern China were analyzed. It follows that the PM 10 concentration in the high-frequency period is higher with an extent 0.009–0.066 mg m −3 than in the low-frequency period of 2001–2002. Further the impacts of three kinds of dust events on the PM 10 concentration in four cities (Beijing, Hohhot, Xi’an and Lanzhou) were explored. The results showed that different kinds of dust events have different influences on variation of PM 10 concentration in these four cities. In Lanzhou and Hohhot, which are near the source areas of dust events, the contribution degree of these three dust events to the PM 10 is: floating dust>dust storm>blowing dust. Whereas, in Beijing and Xi’an situated in dust event passing areas, the mean value of PM 10 concentration is higher in blowing dust than in floating dust (no dust storm). In addition, the influences of dust events on PM 10 concentration are different in the cities on different dust event paths. In Beijing and Hohhot (on the northern path), the high PM 10 concentration is usually caused by blowing dust. But in both Lanzhou and Xi’an (on the western/northwestern path) the high PM 10 pollution concentration is usually caused by floating dust.