Ion concentrations of PM<sub>10–2.5</sub> and PM<sub>2.5</sub> aerosols over the eastern Mediterranean region: seasonal variation and source identification

Abstract

Abstract. The annual averages of particulate matters (PM10, PM10–2.5 (coarse) and PM2.5 (fine)) in a densely populated area of Beirut were measured and found to be 84±27, 53±20 and 31±9 μg m−3, respectively. Ion Chromatography (IC) analysis of the collected PM Teflon filters showed that NaCl, CaSO4 and Ca(NO3)2 were predominant in the coarse particles, while (NH4)2SO4 was the main salt in the fine particles. Using the non destructive Fourier Transform Infra Red-Attenuated Total Reflection (FTIR-ATR) technique, CaCO3 was determined in the coarse filter. In addition, ATR measurements showed that inorganic salts present in the coarse particles are mostly water insoluble while salts found in fine particles are soluble. Concentrations of nitrates and calcium higher than the ones reported in neighboring Mediterranean countries were good indication of high traffic density and crustal dust abundance in Beirut, respectively. The study of the seasonal variation showed that long-range transport of SO2 from Eastern and Central Europe, sandy storms coming from Africa and marine aerosols are considered major sources of the determined inorganic ions. Considering the importance of the health and climate impacts of aerosols locally and regionally, this study constitutes a point of reference for eastern Mediterranean transport modeling studies and local regulatory and policy makers.

In Situ Samplings and Remote Sensing Measurements to Characterize Aerosol Properties over Southeast Italy

“…12 that NO Ϫ 3 , SO 2Ϫ 4 , and Ca 2ϩ are the main ion components: their mass represents 89% of the total ion mass. In addition, we note that SO 2Ϫ 4 is the main ion component of fine-mode particles, in accordance to previous studies (Kouyoumdjian and Saliba 2005) and that its level (6.4 g m Ϫ3 ) is comparables to the SO 2Ϫ 4 levels reported for coastal sites of the central-eastern Mediterranean (e.g., Bardouki et al 2003). The latter results show the significant contribution of sulfates and nitrates to the fine fraction of the aerosol load even during a dust event in accordance to SEM analyses on impactor filters (Fig.…”

“…We believe that the rather high mass concentrations of K ϩ , Mg 2ϩ , and Ca 2ϩ reported in Table 3, are due to the Saharan dust particles collected on 30 June, being K ϩ , Mg 2ϩ , and Ca 2ϩ elements of illite/smectite and dolo- mite particles. In fact, Kouyoumdjian and Saliba (2005) have found in PM2.5 samples collected over the eastern Mediterranean, annual mean concentrations of 0.08, 0.03, and 0.52 g m Ϫ3 for K ϩ , Mg 2ϩ , and Ca 2ϩ , respectively. In contrast, we have found mass concentrations of 0.29, 0.28, and 2.5 g m Ϫ3 for K ϩ , Mg 2ϩ , and Ca 2ϩ , respectively.…”

Anthropogenic fine aerosols dominate over the Pune region, Southwest India

“…In this study, the average ratio of NO 3 − /SO 4 2− was 0.28 ± 0.12 and 0.44 ± 0.33 in fine and coarse particles, indicating a greater contribution of SO 4 2− that shows the dominance of stationary sources compared to vehicular activity. Earlier studies reported a high average NO 3 − /SO 4 2− ratio in cities such as Bobadela (Almeida et al 2005), Rio de Janeiro (Mariani and de Mello 2007) and Beirut (Kouyoumdjian and Saliba 2005) ( Table 2).…”

Functional Factors of Biomass Burning Contribution to Spring Aerosol Composition in a Megacity: Combined FTIR-PCA Analyses

“…Figure 5). Secondary particles that are mainly ammonium sulfate and nitrate formed in the air from regional or local gaseous emissions of sulfur dioxide and oxides of nitrogen reacting with ammonia [55]. SO 4…”