Revealing source signatures in ambient BTEX concentrations

management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-included VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations of their pertinent sources. This study presents an approach that can aid in identifying sources apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to alocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. (C) 2008 Elsevier Ltd. All rights reserved.