Receptor modeling for source apportionment of particle bounded polycyclic aromatic hydrocarbons at an urban location in Spain

Abstract

Polycyclic Aromatic Hydrocarbons (PAH) are a group of organic pollutants, which are mainly formed from both natural and anthropogenic sources. PAH are an environmental concern because their carcinogenic, mutagenic and immuno-toxic properties and for this reason, EPA (Environmental Protection Agency of United States) has included 16 PAH on its list of priority pollutants. In this paper, the PAH associated to the airborne particulate matter less or equal than 2.5 μm (PM2.5) were studied by using two receptor models based on multivariate statistical tools (UNMIX and PMF) in the city of Zaragoza, Spain. A high volume air sampler with a PM2.5 cut off was used to collect samples from June 2011-May 2012. PAH on the particle phase were extracted by Soxhlet and 19 PAH were analyzed by gas-chromatography with mass spectrometry mass spectrometry detection (GC-MS-MS). Chrysene, benzo(b)fluoranthene, fluoranthene, pyrene and benzo(e)pyrene represented the 47% of the average total PAH. Good correlations were obtained between the experimental and the modeled PAH by both models and a comparison of the different quantified factors was carried out. Despite no episodes of benzo(a)pyrene (BaP) equal or higher than 1.0 ng/m3 were obtained (Directive 2004/107/EC), the concentration of PM2.5 exceeded the limit value of 25 μg/m3 (Directive 2008/50/EC) in several occasions. These episodes were interpreted according to both models in order to check the impact of different anthropogenic sources, especially the traffic emissions factor.