PM and surface dust source characterization in Baguio City Central Business District (CBD), Philippines.

This study measured both PM and surface dust concentrations at roadside in the Central Business District of Baguio City. A total of 66 PM filters and 25 surface dust samples were analyzed for 14 metals (Na, Mg, Al, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd and Pb) using inductively coupled plasma mass spectrometer ICP-MS to characterize sources of airborne particulate matter (APM). Calculation of enrichment factors indicated elements Zn, Cd, Pb and As to be enriched in both PM and surface dust samples. The compositional signature of local surface dust was found to be strongly correlated with that of PM particles. Enrichment Factor, Conditional Probability Function (CPF), Correlation Analysis and Principal component analysis were applied to determine sources affecting the Baguio CBD area, and results indicate three APM contributing sources (1) soil sources and (2) soil-road dust resuspension and vehicular emissions (3) vehicular emissions. The NE and SW wind sectors were dominant for most of the identified sources.