Overview of preliminary results on aerosols in ECOCEM - Beirut

The Mediterranean region is an area where polluted air masses coming from Eastern and Central Europe increase air pollution in this region, particularly during stagnation periods. It was demonstrated that the eastern coast of the Mediterranean Sea suffers from this kind of phenomena. However, data are sparse in this region. Therefore, the ECOCEM (Emission and Chemistry of Organic Carbon in the East Mediterranean - Beirut) project aims to improve our understanding of air pollution in this area by studying the composition of the gaseous and particulate phases in Beirut (Lebanon). The goal of the project which is taking place over two field campaigns (July 2011 and February 2012) is to provide valuable data on the temporal variability of several pollutants (summer versus winter), identify the sources of volatile organic compounds (VOCs) and aerosols, to study the origin of secondary organic aerosols (SOA) and the role of the VOCs in the first oxidation steps of SOA formation. We will present an overview of the PM_2.5 composition during the first ECOCEM field campaign (July 2 to 17, 2011, Beirut - Lebanon). PM_2.5 mass concentration varied between 15 and 65 μg.m^-3 as a 12-hour average exceeding by far the World Health Organization recommended values. Samples were taken by high volume and low volume samplers. Filter analyses will be conducted with AMS, GCMS and Fluorescence X. Elemental composition along with organic composition (including EC/OC) will be determined.