University of Gothenburg, Earth Sciences, P.O. Box 460, SE-40530 Gothenburg, Sweden.
University of Gothenburg, Biological and Environmental Sciences, P.O. Box 461, SE-40530 Gothenburg, Sweden.
Sci Total Environ. 2017 Dec 1;599-600:1728-1739. doi: 10.1016/j.scitotenv.2017.05.051. Epub 2017 May 20.
Air pollution levels (NO, PAHs, O) were investigated, before (BLE) and after (ALE) leaf emergence, in the urban landscape of Gothenburg, Sweden. The aims were to study the 1) spatial and temporal variation in pollution levels between urban green areas, 2) effect of urban vegetation on air pollution levels at the same distance from a major emission source (traffic route), 3) improvement of urban air quality in urban parks compared to adjacent sites near traffic, 4) correlation between air pollution and noise in a park. O varied little over the urban landscape. NO varied strongly and was higher in situations strongly influenced by traffic. Four PAH variables were included: total PAH, total particle-bound PAH, the quantitatively important gaseous phenanthrene and the highly toxic particle-bound benzo(a)pyrene. The variation of PAHs was similar to NO, but for certain PAHs the difference between highly and less polluted sites was larger than for NO. At a vegetated site, NO and particulate PAH levels were lower than at a non-vegetated site at a certain distance from a busy traffic route. This effect was significantly larger ALE compared to BLE for NO, indicating green leaf area to be highly significant factor for air quality improvement. For particulate PAHs, the effect was similar BLE and ALE, indicating that tree bark and branches also could be an important factor in reducing air pollution. Parks represented considerably cleaner local environments (park effect), which is likely to be a consequence of both a dilution (distance effect) and deposition. Noise and air pollution (NO and PAH) levels were strongly correlated. Comparison of noise levels BLE and ALE also showed that the presence of leaves significantly reduced noise levels. Our results are evidence that urban green spaces are beneficial for urban environmental quality, which is important to consider in urban planning.
空气污染水平（NO、PAHs、O）在瑞典哥德堡的城市景观中进行了调查，分别在叶芽出现之前（BLE）和之后（ALE）。目的是研究 1）城市绿地之间污染水平的时空变化，2）城市植被对距离主要排放源（交通路线）相同距离处空气污染水平的影响，3）与交通附近相邻地点相比，城市公园改善城市空气质量的效果，4）公园内空气污染与噪音之间的相关性。O 在城市景观中变化不大。NO 变化强烈，在受交通强烈影响的情况下更高。包括四个 PAH 变量：总 PAH、总颗粒结合 PAH、数量上重要的气态菲和高度有毒的颗粒结合苯并(a)芘。PAHs 的变化与 NO 相似，但对于某些 PAHs，高污染和低污染地点之间的差异大于 NO。在植被覆盖的地点，NO 和颗粒状 PAH 水平低于在距繁忙交通路线一定距离的无植被地点。与 BLE 相比，ALE 时 NO 的这种影响明显更大，表明绿叶面积是空气质量改善的重要因素。对于颗粒状 PAHs，BLE 和 ALE 的效果相似，表明树皮和树枝也可能是减少空气污染的重要因素。公园代表了相当清洁的局部环境（公园效应），这很可能是稀释（距离效应）和沉积的结果。噪音和空气污染（NO 和 PAH）水平密切相关。BLE 和 ALE 时噪声水平的比较也表明，叶片的存在显著降低了噪声水平。我们的结果表明，城市绿地对城市环境质量有益，这在城市规划中是需要考虑的重要因素。
