TY - JOUR
T1 - Origin and variability of particulate matter (PM10 and PM2.5) mass concentrations over an Eastern Mediterranean city
AU - Saliba, N. A.
AU - El Jam, F.
AU - El Tayar, G.
AU - Obeid, W.
AU - Roumie, M.
N1 - Funding Information:
The authors would like to thank the American University Research Board (URB) and the Lebanese National Council for Scientific Research for supporting this work. The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website ( http://www.arl.noaa.gov/ready.html ) used in this publication. Moreover, the authors extend a special thank to Dr. A.L. Shihadeh (American University of Beirut, Mechanical Engineering Department) for helpful discussions in the experimental set up of the site in Haret Hreik (HH).
Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2010/7
Y1 - 2010/7
N2 - Being a semi-enclosed area, the Eastern Mediterranean region experiences high Particulate Matter (PM) levels that could be attributed to sources originating from the region and from long-range transported pollutants. In this study, a long-term evaluation of PM10 and PM2.5 mass concentrations reveals that averages of PM10 and PM2.5 concentrations collected between 2003 and 2007 in several different sites in Beirut exceeded the World Health Organization (WHO) PM10 and PM2.5 annual averages (20 and 10μgm-3, respectively). When compared to other sites in the region, levels fell in general outside the usual range for most other urban sites that are not directly affected by industrial activity. The average PM2.5/PM10 ratios were about 0.42, a value that is typical of urban sites. The overall averages for different seasons were higher in fall and summer as a result of low precipitations, the increase of dust storm activities in fall and the enhancement of sea and land breezes in summer, along with the increase in traffic activities (summer is a high touristic season). Using the HYSPLIT model for about 500 sampled days in Beirut, Lebanon, it was found that 60% of the wind comes from the N, NW and NE, while the remaining 40% comes from the S, SW and SE. Comparing the sources assigned to the pre- (BH) and post- (HH) 2006-war sites, it was found that aged dust increased by 64% in total PM10 and secondary aerosols by 150% in fine PM in HH over BH. Furthermore, much higher average percentages of sulfates and nitrates were determined in fine PMs in HH, indicating increased levels of their precursors NOx, SOx and Ca generated from a higher density of gasoline, diesel vehicles and construction debris.
AB - Being a semi-enclosed area, the Eastern Mediterranean region experiences high Particulate Matter (PM) levels that could be attributed to sources originating from the region and from long-range transported pollutants. In this study, a long-term evaluation of PM10 and PM2.5 mass concentrations reveals that averages of PM10 and PM2.5 concentrations collected between 2003 and 2007 in several different sites in Beirut exceeded the World Health Organization (WHO) PM10 and PM2.5 annual averages (20 and 10μgm-3, respectively). When compared to other sites in the region, levels fell in general outside the usual range for most other urban sites that are not directly affected by industrial activity. The average PM2.5/PM10 ratios were about 0.42, a value that is typical of urban sites. The overall averages for different seasons were higher in fall and summer as a result of low precipitations, the increase of dust storm activities in fall and the enhancement of sea and land breezes in summer, along with the increase in traffic activities (summer is a high touristic season). Using the HYSPLIT model for about 500 sampled days in Beirut, Lebanon, it was found that 60% of the wind comes from the N, NW and NE, while the remaining 40% comes from the S, SW and SE. Comparing the sources assigned to the pre- (BH) and post- (HH) 2006-war sites, it was found that aged dust increased by 64% in total PM10 and secondary aerosols by 150% in fine PM in HH over BH. Furthermore, much higher average percentages of sulfates and nitrates were determined in fine PMs in HH, indicating increased levels of their precursors NOx, SOx and Ca generated from a higher density of gasoline, diesel vehicles and construction debris.
KW - African dust
KW - Beirut
KW - Lebanon
KW - Mediterranean air pollution
KW - PM composition
KW - Source apportionment
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U2 - 10.1016/j.atmosres.2010.03.011
DO - 10.1016/j.atmosres.2010.03.011
M3 - Article
AN - SCOPUS:77953870383
SN - 0169-8095
VL - 97
SP - 106
EP - 114
JO - Atmospheric Research
JF - Atmospheric Research
IS - 1-2
ER -