10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Spatial and Temporal Variability in Chemical Composition of Fine Particulate Matter and Human Health Impact Assessment for the Megacity of Karachi, Pakistan
Lurie Kelly, HAIDER KHWAJA, Shedrack Nayebare, Zafar Fatmi, David Carpenter, Daniel Malashock, Azhar Siddique, Kamran Khan, Mirza M. Hussain, Fida Khatib, Wadsworth center, University at Albany
Abstract Number: 978 Working Group: Health Related Aerosols
Abstract Karachi, Pakistan is one of the largest and most polluted metropolitan city in southeast Asia. Air quality was assessed 24-hour fine-particulate matter (PM2.5) samples collected from two sites, Korangi (industrial/residential) and Tibet Center (commercial/residential). Spatial and temporal characteristics and sources of pollution were evaluated from August 2008 through August 2009 using samples analyzed for PM2.5, black carbon (BC), trace metals, and water-soluble ions. Enrichment factors were calculated, and a receptor model was used to identify anthropogenic and natural source contributions. PM2.5 concentrations exceeded the WHO Guideline of 20 µg/m3, ranging from 30 to 279 µg/m3. The average for Korangi (102 µg/m3) was greater than that for Tibet Center (77 µg/m3). Average PM2.5 concentrations were higher in the winter, suggesting increased burning and decreased air dispersion. Enrichment factors suggest abundant seasonal contributions of trace metals from anthropogenic activities. Concentrations of pollutants were higher at the Korangi site as compared to the Tibet Center, indicative of emissions from industrial activities near the site. Positive Matrix Factorization (PMF) was utilized to quantify sources of ambient PM2.5. The identified sources and their percent contributions for Korangi and Tibet Center sites, respectively, are oil combustion (25% and 21%), soil and urban dust resuspension (28% and 25%), vehicular emissions (23% and 5%), sea spray (13% and 26%), and industrial emissions (11% and 23%). Human health risk assessments and impacts were evaluated and identified major air pollution concerns for Karachi, Pakistan, highlighting the need for stringent laws on PM2.5 emission control to protect human health and the environment.