太原市采暖期前后交通路口PM2.5污染状况分析

目的了解山西省太原市采暖期前后交通路口细颗粒物(PM2.5)污染状况及其影响因素,为交通环境PM2.5污染防治提供依据。方法以太原市康乐街路口为监测点,2010年10—11月连续采样,采用质量法测定PM2.5浓度,记录气温、气压、风速和车流量。结果10月和11月交通路口PM2.5的平均日浓度分别为0.137、0.162 mg/m³,均高于2006年美国环境保护局(EPA)新颁布的PM2.5标准(0.035 mg/m³),其超标百分率分别为100%和96.7%;采暖前PM2.5浓度低于采暖后浓度(P<0.01);早晨、中午和下午PM2.5浓度差异无统计学意义;细颗粒物的浓度与风速、温度和气压呈负相关,与车流量呈正相关。结论太原市交通路口PM2.5污染严重,其浓度受到风速、温度、气压和车流量的影响,应对之加强治理。

Air pollution of PM2.5 at traffic crossroad before and in heating period in Taiyuan city

ObjectiveTo assess air pollution levels and affecting factors of particulate matter less than 2.5 microns in aerodynamic diameter(PM2.5)at traffic crossroad during heating period and non-heating period in Taiyuan and to provide reference for the preventoin of PM2.5 pollution in traffic environment.MethodsKangle crossroad was selected as the monitoring site and continuous sampling was performed from October to November in 2010.The concentration of PM2.5 was determined by membrane weighting method.And the temperature,wind speed,atmospheric pressure and traffic vehicle flow were recorded at the site.Results In October and November,the daily average concentration of PM2.5 were 0.137 mg/m³ and 0.162mg/m³,respectively,which were both higher than air quality standard for PM2.5 of US Environmental Protection Agency(EPA)(issued in 2006).The unqualified rate of PM2.5 concentration in October and November were 100% and 96.7%,respectively.Concentration of PM2.5 in heating period was higher than that in non-heating period(P<0.01).There was no difference in PM2.5 concentration in the morning,midday and afternoon.Negative correlations were observed between concentration of PM2.5 and wind speed,temperature,and atmospheric pressure,and a positive correlation between PM2.5 and traffic vehicles flow was observed.ConclusionPM2.5 pollution at traffic crossroad is very serious in Taiyuan.The concentration is affected by wind speed,temperature,atmospheric pressure,and traffic vehicle flow.PM2.5 pollution should be concerned.