The impact of an anti-idling campaign on outdoor air quality at four urban schools
The impact of an anti-idling campaign on outdoor air quality at four urban schools
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DOI：
10.1039/c3em00377a
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发表时间：
2013-01-01
影响因子：
5.5
通讯作者：
Grinshpun, Sergey A.
中科院分区：
文献类型：
--
作者：
Ryan, Patrick H.;Reponen, Tiina;Grinshpun, Sergey A.
闲置校车可能会增加学校附近的空气污染物浓度，包括细颗粒物（PM2.5）和元素碳（EC）。减少学校附近车辆空转的努力很少包括空气采样，以客观评估空气污染物浓度的变化。其目的是确定在四所学校的室外空气质量与不同的暴露于公共汽车和汽车交通的反空转运动的影响。我们在四间学校进行为期五天的户外空气采样，以检测PM2.5、EC和粒子数浓度。采样在上午巴士到达之前开始，并在下午离开后结束。同时在四个相应的社区地点进行采样。在PM2.5，EC，和PNC测量在学校和社区网站的每个采样日的差异计算之前和之后的运动。在运动之前，四所学校中有三所学校在上学期间的PM2.5平均室外浓度超过社区背景水平，并且在公交车最多的学校（n = 39）差异最大（4.11 μ g m（-3），p < 0.01）。学校和社区之间的EC差异最大的也是在公交车数量最多的学校（0.40 μ g m（-3），p < 0.01）。在反空转运动之后，拥有最多公交车的学校的PM2.5的平均差异从4.11 μ g m（-3）下降到0.99 μ g m（-3）（p < 0.05）。同样，在这所学校，EC水平的差异从0.40 μ g m（-3）降至0.15 μ g m（-3），PNC从11560降至1690颗粒/cm（3）（p < 0.05）。公交车较少的学校（n = 5-11）的室外污染物浓度没有显着降低。学校附近的空气污染物浓度可能会大大超过社区的背景水平，特别是当校车空转时。在有大量巴士和客运汽车的学校，反空转车辆有效减少PM2.5、EC和PNC。
Idling school buses may increase concentrations of air pollutants including fine particulate matter (PM2.5) and elemental carbon (EC) near schools. Efforts to reduce vehicle idling near schools have rarely included air sampling to objectively assess changes in concentrations of air pollutants. The objective was to determine the impact of an anti-idling campaign on outdoor air quality at four schools with varying exposure to bus and automobile traffic. Outdoor air sampling for PM2.5, EC and particle number concentration (PNC) was conducted at four schools for five days before and after an anti-idling campaign. Sampling began before the morning arrival of buses and concluded after their afternoon departure. Sampling was simultaneously conducted at four corresponding community sites. Differences in PM2.5, EC, and PNC measured at school and community sites for each sampling day were calculated before and after the campaign. Before the campaign, the average outdoor concentration of PM2.5 during the school day at three of the four schools exceeded community background levels and the difference was greatest (4.11 mu g m(-3), p < 0.01) at the school with the most buses (n = 39). The largest difference in EC between school and community sites was also observed at the school with the greatest number of buses (0.40 mu g m(-3), p < 0.01). Following the anti-idling campaign, the average difference in PM2.5 at the school with the most buses decreased from 4.11 mu g m(-3) to 0.99 mu g m(-3) (p < 0.05). Similarly, at this school, the difference in the EC level decreased from 0.40 mu g m(-3) to 0.15 mu g m(-3) and PNC decreased from 11 560 to 1690 particles per cm(3) (p < 0.05). The outdoor concentrations of pollutants at schools with fewer buses (n = 5-11) were not significantly reduced. The concentration of air pollutants near schools may significantly exceed community background levels, particularly in the presence of idling school buses. Anti-idling campaigns are effective in reducing PM2.5, EC and PNC at schools with significant amounts of buses and passenger cars.