Contribution of railway traffic to local PM10 concentrations in Switzerland
Contribution of railway traffic to local PM10 concentrations in Switzerland
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DOI：
10.1016/j.atmosenv.2006.09.021
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发表时间：
2007-02
影响因子：
5
通讯作者：
R. Gehrig;M. Hill;P. Lienemann;C. N. Zwicky;N. Bukowiecki;E. Weingartner;U. Baltensperger;B. Buchmann
中科院分区：
文献类型：
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作者：
R. Gehrig;M. Hill;P. Lienemann;C. N. Zwicky;N. Bukowiecki;E. Weingartner;U. Baltensperger;B. Buchmann
在苏黎世瑞士最繁忙的火车站附近的两个地点（距离铁轨10米）和一个非常忙碌的铁路线附近的一个地点（每天有700多列火车）进行了不同季节的PM10及其元素组成（每天在过滤器上取样）的实地测量活动。在后一个站点，在距离铁轨10、36和120米处采集了平行样本，目的是研究铁路引起的PM10浓度的距离依赖性。为了区分相对较小的铁路排放与区域背景（通常为20-25μgm−3），还在苏黎世的一个城市背景站点同时采集了样本。铁路暴露的网站和背景网站之间的PM10和元素浓度的差异被分配到铁路的贡献。小，但是，可测量的PM10浓度差异被发现在所有网站。这些差异的元素组成表明铁是唯一重要的定量成分。作为一个长期平均值，在所有三个地点距离轨道10米处的铁含量约为1μgm− 3。假设铁至少部分被氧化（例如以Fe 2 O3的形式），则贡献可以达到1.5μgm−3。火车排放的铜、锰和铬也被明确确定。然而，与铁相比，这些元素的排放量非常低。没有观察到岩石材料（钙、铝、镁、钠）的显著贡献，这可能与轨道下方砾石的侵蚀、磨损和再悬浮有关。柴油机尾气的颗粒物排放没有被考虑，因为瑞士的火车几乎完全由电力机车运营。铁路，引起的贡献，环境PM10迅速下降，从轨道的距离增加。在120米的距离，这一贡献下降到只有25%，在10米的距离观察到的贡献。
Field measurement campaigns of PM10 and its elemental composition (daily sampling on filters) covering different seasons were performed at two sites near the busiest railway station of Switzerland in Zurich (at a distance of 10m from the tracks) and at a site near a very busy railway line with more than 700 trains per day. At this latter site parallel samples were taken at 10, 36 and 120m distances from the tracks with the aim to study the distance dependence of the railway induced PM10 concentrations. To distinguish the relatively small railway emissions from the regional background (typically 20–25μgm−3), simultaneous samples were also taken at an urban background site in Zurich. The differences in PM10 and elemental concentrations between the railway exposed sites and the background site were allocated to the railway contribution. Small, however, measurable PM10 concentration differences were found at all sites. The elemental composition of these differences revealed iron as the only quantitatively important constituent. As a long-term average it amounted to approximately 1μgm−3Fe at a distance of 10m from the tracks at all three sites. Assuming that iron was at least partly oxidised (e.g. in the form of Fe2O3) the contribution can amount up to 1.5μgm−3. Emissions of copper, manganese and chromium from trains were also clearly identified. However, compared to iron these, elements were emitted in very low quantities. No significant contribution from rock material (calcium, aluminium, magnesium, sodium) was observed as might have been expected from erosion, abrasion and resuspension from the gravel below the tracks. Particle emissions from diesel exhaust were not considered as trains in Switzerland are operated nearly exclusively by electric locomotives. The railway, induced contribution to ambient PM10 decreased rapidly with increasing distance from the tracks. At a distance of 120m this contribution dropped to only 25% of the contribution observed at 10m distance.