AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Source Apportionment and Temporal Trends of Coarse Particulate Matter (PM): A Case Study in Central Tehran, Iran
EHSAN SOLEIMANIAN, Sina Taghvaee, Amirhosein Mousavi, Mohammad Sowlat, Mohammad Sadegh Hassanvand, Masud Yunesian, Kazem Naddafi, Constantinos Sioutas, University of Southern California
Abstract Number: 18 Working Group: Source Apportionment
Abstract Positive matrix factorization (PMF) receptor model was employed to identify the sources of coarse particulate matter (PM) and their corresponding seasonal variations in two locations (i.e., a school dormitory and a retirement home) in central Tehran. Daily samples were collected from ambient PM using low-volume air samplers (FRM OMNUTM air sampler, multi-cut inlet; BGI, USA) within May 2012 to June 2013. Water-soluble ions, metals, and trace elements were used as the input data to the PMF model after analyzing the chemical constituents of the filter samples. Results represented an annual coarse PM average concentration of 45.7 ± 3.8 µg/m3 and 38.4 ± 4.5 µg/m3 at the school dormitory and the retirement home, respectively, with higher concentration in summer as opposed to the winter phase. PMF solutions suggested road dust, soil and industry, and sea salt as the three major sources of ambient coarse PM in central Tehran with the corresponding contributions of 74 ± 9%, 19 ± 2%, and 7 ± 1% to total coarse PM mass concentration, respectively. The temporal trends of the resolved factors indicated higher contribution of road dust to total coarse PM mass concentration during warm phase as a result of higher wind speed and temperature as well as lower relative humidity which leads to an increase in resuspension rate from road surfaces. Additionally, dust storms in combination with higher resuspension rate of mechanically originated particulates leaded to higher summertime contribution of soil factor to coarse PM. Results from this study provide insight regarding the importance of non-tail pipe emissions on ambient coarse PM mass concentration in Tehran.