Characterization of ionic composition of TSP and PM10 during the Middle Eastern Dust (MED) storms in Ahvaz, Iran
Because of the recent frequent observations of major dust storms in southwestern cities in Iran such as Ahvaz, and the importance of the ionic composition of particulate matters regarding their health effects, source apportionment, etc., the present work was conducted aiming at characterizing the ionic composition of total suspended particles (TSP) and particles on the order of ∼10 μm or less (PM10) during dust storms in Ahvaz in April–September 2010. TSP and PM10 samples were collected and their ionic compositions were determined using an ion chromatography. Mean concentrations of TSP and PM10 were 1,481.5 and 1,072.9 μg/m3, respectively. Particle concentrations during the Middle Eastern Dust (MED) days were up to four times higher than those in normal days. Ionic components contributed to only 9.5% and 11.3% of the total mass of TSP and PM10, respectively. Crustal ions were most abundant during dust days, while secondary ions were dominant during non-dust days. Ca2+/Na+ and Cl−/Na+ ratios can be considered as the indicators for identification of the MED occurrence. It was found that possible chemical forms of NaCl, (NH4)2SO4, KCl, K2SO4, CaCl2, Ca(NO3)2, and CaSO4 may exist in TSP. Correlation between the anionic and cationic components suggests slight anion and cation deficiencies in TSP and PM10 samples, though the deficiencies were negligible.
KeywordsThe Middle Eastern Dust storm TSP PM10 Water-soluble ions Ahvaz
This work was part of a PhD thesis funded by Tehran University of Medical Sciences (research project number #9742) and Institute for Environmental Research (IER). We wish to thank the Iranian National of Institute Health Research (NIHR) for provision of the location for sampling station and cooperation in the sampling.
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