珠海西区空气中颗粒物(PM2.5)污染水平的初步研究

目的监测分析珠海西区PM2.5污染水平。方法选择城乡固定监测点,以中流量采样器采集大气中的PM2.5,重量法测定,每个点采样3 d以上。结果珠海市西区PM2.5平均浓度为0.092 mg/m3;城区PM2.5平均浓度为0.10 mg/m3,乡村平均浓度为0.078 mg/m3,(P>0.05);在交通繁忙路段(车流量>200辆/5 min)PM2.5平均浓度为0.13 mg/m3,非繁忙路段(车流量<200辆/5 min)平均浓度为0.084 mg/m3,(P<0.01);风速>0.5 m/s时,PM2.5平均浓度为0.054 mg/m3,风速<0.5 m/s时,PM2.5平均浓度为0.11 mg/m3,(P<0.01)。结论珠海市西区PM2.5污染水平较国内其他大城市低,但超过了美国和世界卫生组织的标准限值;城乡污染无显著性差异;交通繁忙路段明显高于非繁忙路段;风速提高时,污染水平显著降低。

Preliminary Study of the Airborne Particulate Matter 2.5 in Western Region of Zhuhai

Objectives To monitor and analyze the PM2.5 level in Western Region of Zhuhai. Methods Airborne PM25 samples were collected with medium flow samplers at typical fields of both countryside and downtown areas, and determined by gravimetric method for more than 3 days of sampling in each field. Results Firstly, the average concentration of PM2.5 of western region of Zhuhai was 0.092 mg/m3, while that was 0. lO mg/m3 in city area and that was O. 078 mg/m3 in countryside （P 〉0.05）. Secondly, the average PM2.5 level was 0. 13 mg/m3 during heavy traffic time （more than 200 motor vehicles passing per 5 rain） and 0. 084 mg/m3 during the time not so much traffic （less than 200 motor vehicles passing per 5 rain） （P 〈 0. 01 ）. Thirdly, the average concentration of PM25 was 0. 054 mg/m3 and 0. 11 mg/m3 respectively when wind speed was beyond 0.5 m/s or not （P 〈 0.01 ）. Conclusions The average PM2.s level in Western Region of Zhuhai was lower than that in other big cities in China, but it was still higher than the standards of U. S. A and WHO. There was no significant difference （P 〉 0.05） between PM2.5 levels of city and countryside in Western Region of Zhuhai. Moreover, PM25 levels on roads with heavy traffic were significantly higher than those with light traffic. Finally, PM 25 levels reduced significantly when the wind speed was beyond 0.5 m/s （P 〈0.01 ）.