Determination of the Concentration and Composition of PM10 during the Middle Eastern Dust Storms in Sanandaj, Iran.

BACKGROUND The present study investigated the effect of the Middle East dust storm episodes on the concentration and composition of PM10 during April to September 2013 in Sanandaj City, western Iran. METHODS Sampling was once every six days, and on dusty days using an Omni air sampler. The PM10 sample was collected on polytetrafluoroethylene filters. Average of 24 h values of PM10 mass concentrations was determined. Half of each sample filter and blank filter was analyzed for water -soluble ions and the other half was digested for metal analysis. RESULTS The average PM10 concentration was 160.63 μg/m3. The lowest and highest concentrations of PM10 were in May and June respectively. The average PM10 concentration during the non-dusty days was 96.88 (μg /m3). Nevertheless, it increased by 4.8 times during the dusty days. Ca2+, Cl-, NO3-, and Na+ accounted for 71% of total water-soluble ions on the dusty days. During the dusty days, the dominant elements in PM10 were Na, Ca, Mg, Al, and Fe contributing to 95.72% of total measured metals. The correlation coefficient and enrichment factor analysis have shown that on dusty days, Al, Ca, Fe, K, Mg, Na, Sr, and V were the elements with the crustal sources. CONCLUSIONS Concentrations of PM10 during dusty days were considerably higher than that during non-dusty days. In addition, concentrations of water-soluble ions and metals were also higher during dusty days.