Font Anna, Fuller Gary W
Environmental Research Group, MRC PHE Centre for Environment and Health, King's College London, London, SE1 9NH, United Kingdom.
Environmental Research Group, MRC PHE Centre for Environment and Health, King's College London, London, SE1 9NH, United Kingdom.
Environ Pollut. 2016 Nov;218:463-474. doi: 10.1016/j.envpol.2016.07.026. Epub 2016 Jul 21.
A large number of policy initiatives are being taken at the European level, across the United Kingdom and in London to improve air quality and reduce population exposure to harmful pollutants from traffic emissions. Trends in roadside increments of nitrogen oxides (NO), nitrogen dioxide (NO), particulate matter (PM), black carbon (CBLK) and carbon dioxide (CO) were examined at 65 London monitoring sites for two periods of time: 2005-2009 and 2010-2014. Between 2005 and 2009 there was an overall increase in NO reflecting the growing evidence of real world emissions from diesel vehicles. Conversely, NO decreased by 10%·year from 2010 onwards along with PM (-28%·year) and black carbon (-11%·year). Downwards trends in air pollutants were not fully explained by changes in traffic counts therefore traffic exhaust emission abatement policies were proved to be successful in some locations. PM concentrations showed no significant overall change suggesting an increase in coarse particles which offset the decrease in tailpipe emissions; this was especially the case on roads in outer London where an increase in the number of Heavy Good Vehicles (HGVs) was seen. The majority of roads with increasing NO experienced an increase in buses and coaches. Changes in CO from 2010 onwards did not match the downward predictions from reduced traffic flows and improved fleet efficiency. CO increased along with increasing HGVs and buses. Polices to manage air pollution provided differential benefits across London's road network. To investigate this, k-means clustering technique was applied to group roads which behaved similarly in terms of trends to evaluate the effectiveness of policies to mitigate traffic emissions. This is the first time that London's roadside monitoring sites have been considered as a population rather than summarized as a mean behaviour only, allowing greater insight into the differential changes in air pollution abatement policies.
在欧洲层面、整个英国以及伦敦，正在采取大量政策举措来改善空气质量，减少民众接触交通排放产生的有害污染物。在伦敦的65个监测点，对两个时间段（2005 - 2009年和2010 - 2014年）的氮氧化物（NO）、二氧化氮（NO₂）、颗粒物（PM）、黑碳（CBLK）和二氧化碳（CO）的路边增量趋势进行了研究。2005年至2009年期间，NO总体呈上升趋势，这反映出柴油车辆实际排放的证据越来越多。相反，从2010年起，NO₂、PM（每年下降28%）和黑碳（每年下降11%）每年下降10%。交通流量的变化并不能完全解释空气污染物的下降趋势，因此交通尾气减排政策在某些地方被证明是成功的。PM浓度总体没有显著变化，这表明粗颗粒的增加抵消了排气管排放的减少；在伦敦外围道路尤其如此，重型货车（HGV）数量有所增加。NO增加的大多数道路上，公交车和长途客车数量也有所增加。2010年起CO的变化与交通流量减少和车队效率提高带来的下降预测不相符。CO随着HGV和公交车数量的增加而增加。管理空气污染的政策在伦敦的道路网络中带来了不同的效益。为了对此进行调查，采用k均值聚类技术对趋势相似的道路进行分组，以评估减轻交通排放政策的有效性。这是首次将伦敦的路边监测点视为一个总体，而不仅仅是汇总为平均行为，从而能够更深入地了解空气污染减排政策的差异变化。
