Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD 20742, USA.
Environ Res. 2013 Apr;122:52-7. doi: 10.1016/j.envres.2012.12.005. Epub 2013 Feb 20.
In this natural intervention study, we evaluated the impact of vehicular shutdown during bandhas (general strikes) and meteorological parameters on ambient PM10 concentrations (particulate matter of aerodynamic diameter 10 μm or less) in the Kathmandu Valley, Nepal. Publicly available PM10 data (January 2003-February 2008) collected at six monitoring stations were combined with meteorological and bandh data. Linear mixed effects regression models were used to examine the effects of bandhas on PM10 concentrations. Lower PM10 concentrations were observed during the monsoon season compared to the winter, across all monitoring stations, with the largest reduction observed for the urban high traffic area (mean ± standard deviation: 290 ± 71 vs 143 ± 36 μg/m(3)). In the high traffic area, there was 36 μg/m(3) decrease in PM10 concentration during the bandh period compared to 2 days preceding the bandh, adjusting for season, rainfall, temperature, and windspeed. The improvements in air quality were short lived: PM10 concentration in the urban high traffic area increased by an average of 26 μg/m(3) within the first 2 days after the bandh. Our results suggest that controlling vehicular traffic can have an immediate impact in improving particulate matter air quality even among the most polluted cities in the world.
在这项自然干预研究中，我们评估了尼泊尔加德满都谷地在班达（总罢工）期间和气象参数对环境 PM10 浓度（空气动力学直径 10μm 或以下的颗粒物）的影响。结合气象和班达数据，使用线性混合效应回归模型来检验班达对 PM10 浓度的影响。在所有监测站，与冬季相比，季风季节的 PM10 浓度较低，在交通繁忙的市区，降幅最大（平均值±标准差：290±71μg/m3 与 143±36μg/m3）。在交通繁忙地区，班达期间的 PM10 浓度比班达前 2 天下降了 36μg/m3，调整了季节、降雨量、温度和风速。空气质量的改善是短暂的：班达结束后的头 2 天，市区交通繁忙地区的 PM10 浓度平均增加了 26μg/m3。我们的研究结果表明，即使在世界上污染最严重的城市中，控制车辆交通也能立即对改善颗粒物空气质量产生影响。
