International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Australia; Institute for Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
Institute of Environmental Assessment and Water Research, Spanish National Research Council Barcelona, Spain.
Environ Int. 2016 Mar;88:142-149. doi: 10.1016/j.envint.2015.12.029. Epub 2016 Jan 4.
Ambient ultrafine particle number concentrations (PNC) have inhomogeneous spatio-temporal distributions and depend on a number of different urban factors, including background conditions and distant sources. This paper quantitatively compares exposure to ambient ultrafine particles at urban schools in two cities in developed countries, with high insolation climatic conditions, namely Brisbane (Australia) and Barcelona (Spain). The analysis used comprehensive indoor and outdoor air quality measurements at 25 schools in Brisbane and 39 schools in Barcelona. PNC modes were analysed with respect to ambient temperature, land use and urban characteristics, combined with the measured elemental carbon concentrations, NOx (Brisbane) and NO2 (Barcelona). The trends and modes of the quantified weekday average daily cycles of ambient PNC exhibited significant differences between the two cities. PNC increases were observed during traffic rush hours in both cases. However, the mid-day peak was dominant in Brisbane schools and had the highest contribution to total PNC for both indoors and outdoors. In Barcelona, the contribution from traffic was highest for ambient PNC, while the mid-day peak had a slightly higher contribution for indoor concentrations. Analysis of the relationships between PNC and land use characteristics in Barcelona schools showed a moderate correlation with the percentage of road network area and an anti-correlation with the percentage of green area. No statistically significant correlations were found for Brisbane. Overall, despite many similarities between the two cities, school-based exposure patterns were different. The main source of ambient PNC at schools was shown to be traffic in Barcelona and mid-day new particle formation in Brisbane. The mid-day PNC peak in Brisbane could have been driven by the combined effect of background and meteorological conditions, as well as other local/distant sources. The results have implications for urban development, especially in terms of air quality mitigation and management at schools.
环境超细颗粒物数浓度（PNC）具有不均匀的时空分布，取决于许多不同的城市因素，包括背景条件和远距离源。本文定量比较了两个发达国家城市（澳大利亚布里斯班和西班牙巴塞罗那）的城市学校中环境超细颗粒的暴露情况。分析使用了布里斯班 25 所学校和巴塞罗那 39 所学校的综合室内外空气质量测量数据。针对环境温度、土地利用和城市特征，结合测量的元素碳浓度、NOx（布里斯班）和 NO2（巴塞罗那），对 PNC 模式进行了分析。两个城市之间量化的工作日平均日循环环境 PNC 趋势和模式存在显著差异。在这两个城市，交通高峰时段都观察到 PNC 增加。然而，布里斯班学校的中午高峰占主导地位，对室内外 PNC 总量的贡献最大。在巴塞罗那，交通对环境 PNC 的贡献最高，而中午高峰对室内浓度的贡献略高。对巴塞罗那学校 PNC 与土地利用特征之间关系的分析表明，与道路网面积百分比呈中度相关，与绿地面积百分比呈负相关。布里斯班则没有发现具有统计学意义的相关性。总体而言，尽管这两个城市有许多相似之处，但基于学校的暴露模式却有所不同。巴塞罗那学校环境 PNC 的主要来源是交通，而布里斯班则是中午新粒子形成。布里斯班中午 PNC 高峰可能是由于背景和气象条件以及其他本地/远距离源的综合影响所致。研究结果对城市发展具有重要意义，特别是在学校空气质量缓解和管理方面。
