Source apportionment of fine particles at urban background and rural sites in the UK atmosphere

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• 作者：Jianxin Yin ; Roy M. Harrison ; Qiang Chen ; Andrew Rutter ; James J. Schauer
• 关键词：PM_2.5 ; Source apportionment ; Chemical mass balance ; Mass closure ; Chemical composition
• 刊名：Atmospheric Environment
• 出版年：2010
• 出版时间：February 2010
• 年：2010
• 卷：44
• 期：6
• 页码：841-851
• 全文大小：909 K

文摘

Airborne fine particulate matter (PM_2.5) has been collected at two sites in the West Midlands conurbation, UK, representing urban background and rural locations. Chemical analyses have been carried out for major anions, trace metals, total OC and EC, and for individual organic marker species including n-alkanes, hopanes, PAHs, organic acids and sterols. Source apportionment has been conducted using both a pragmatic mass closure model and the US EPA chemical mass balance (CMB) model. The pragmatic mass closure model is well able to account for the measured PM_2.5 mass in terms of chemical/source components, and the chemical mass balance model has been used to apportion the carbonaceous component of the aerosol. The dominant components of PM_2.5 at both sites are secondary inorganic (sulphate and nitrate) and carbonaceous particles. The CMB model shows the latter to arise mainly from road traffic sources, with smaller contributions from vegetative detritus, wood smoke, natural gas, coal, and dust/soil. The CMB model also identifies an important component of the organic aerosol not associated with these primary sources, which correlates very strongly with secondary organic aerosol estimated from the OC/EC ratio. The split between different automotive source types does not relate well to UK emission inventories, and may indicate that CMB source profiles from North American studies and different carbon analysis protocols may lead to erroneous conclusions.