粤东3市PM2.5和PM10质量浓度分布特征

The Distribution of PM2.5 and PM10 Levels at Three Cities in Eastern Guangdong Province

采用在线监测方法，于2009—07—08—2009—07—22在广东省汕头、潮州、揭阳3市各选择1个有代表性的空气质量监测点，同步进行PM2s和PM2.5监测。结果表明，粤东3市PMzs和PM，o质量浓度低于部分沿海城市；PM2.5与PM2.5的质量浓度13变化呈双峰分布。分别处在上午（6：00—10：00）以及下午（18：00—22：00）2个时间段；PM2.5与PM25日平均浓度变化呈周期性波动，周期约为3～4d；对于粤东3市区域，PMzs／PM15值为0．5215，说明PM2.5中细颗粒物含量大于粗颗粒物含量。

A representative spot for monitoring air quality was chosen each at three cities of Shantou, Chaozhou and Jieyang in Guangdong Province, meanwhile PM2s and PM10 were monitored simultaneously by continuous on-line monitoring method from 8 till 22 July 2009. The observations showed that the levels of PM25 and PMlo at those three cities of eastern Guangdong were lower than at several other coastal ones. PM^o and PM2.s levels had a similar diurnal variation with bimodal distribution within a day occurring at 6：00-10：00 am in the morning and at 6：00-10：00 pm in the afternoon and evening. The daily mean levels of PM2.5 and PM2.5 presented a periodic fluctuation with a cycle about 3 to 4 days. The ratio of PM2.5 to PMlo was 0.521 5 in this region indicating that medium-to-fine particulates were predominant in PM10.