Evaluation and mapping of PM2.5 atmospheric aerosols in Arasia region using PIXE and gravimetric measurements

(1) Accelerator Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, Beirut, Lebanon
(2) INFN-Florence and Department of Physics and Astronomy, University of Florence, via G. Sansone 1, 50019-Sesto Fiorentino, Italy
(3) Atomic Energy Commission of Syria, Damascus, Syria
(4) Department of Physics, Jordan University,Amman, Jordan
(5) Physics Department, Faculty of Arts and Sciences, American University of Sharjah, Sharjah, United Arab Emirates
(6) International Atomic Energy Agency, Vienna, Austria
(7) Ministry of Sciences and Technology, Baghdad, Iraq

Air pollution is a worldwide problem that can affect the environment and human health. However, in Arasia region (Arab countries in Asia) there is lack of enough data and study dealing with this issue. It is obvious from the few studies conducted in the Eastern Mediterranean region that Particulate Matter (PM) levels in air are much higher than in other regions, even when compared to the Western Mediterranean. Besides, atmospheric aerosols of PM10 and PM2.5 (aerosol particles with aerodynamic diameter less than 10 and 2.5 um respectively) are trans-boundary and can effectively contribute to air pollution in a certain localized areas. Thus, the current work is a part of a study conducted among several Arab countries in west Asia, under an IAEA regional technical cooperation project for Arasia region. It consists of a simultaneous sampling of PM10 and PM2.5 using an ISAP®1050e sampler having a combined inlet. Few months ago, the first regional campaign, within the IAEA-RAS/0/072 project, was launched simultaneously in Lebanon, Iraq, Jordan, Syria and United Arab emirates, using a unified sampling and analysis protocol.

For the moment, it is based on 24-hour sampling, every six day and is focused on the sampling of PM2.5 from a single location in each country, supposed to represent the urban background of air quality. The different PM2.5 samples collected on Teflon filters were analyzed by PIXE technique at the external beam facility of LABEC laboratory of INFN in Florence (Italy) using a 3 MeV proton beam and the dedicated array of 3 Silicon Drift Detectors in order to determine their elemental composition. The following elements were detected simultaneously: Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Pb, beside  some other occasional elements found in particular samples. Furthermore, a gravimetric measurement was done to determine the total aerosol mass.  This project is unique as it addresses a gap in the available data and information about regional background pollutants. It aims to produce for the first time a data base of PM elemental concentrations in the region that will help in future studies on air quality and consequent pollution. In this work, it will be shown the first results of this opportune regional study.