Source Apportionment and Characterization of Particulate Matter (PM10) in Urban Environment of Lahore

Abstract

The present study describes the characterization of carbonaceous species including elemental carbon (EC), organic carbon (OC), total carbon (TC), crustal (Al, Ca, Mg, Fe, S, and Ti) and trace metals (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, Sn and Zn) in PM10 samples collected from an urban site in Lahore, Pakistan. Sources of various pollutants and their characterization have been carried out using positive matrix factorization (PMF) model. The carbonaceous species (TC, OC, EC) and metals were measured in PM10 samples by NIOSH protocol using Sunset lab instruments and ICP-OES respectively. PM10 concentrations varied from 254 to 555 µg/m3 with an average of 406 ± 87 µg/m3. The elemental carbon (EC) concentration varied from 3 to 56 µg/m3 with an average of 21 ± 15 µg/m3. While the organic carbon (OC) concentrations varied from 21 to 212 µg/m3 with an average of 63 ± 42 µg/m3. The OC/EC ratio varied from 1.5–7.6 with an average of 3.9 ± 1.6, indicating a contribution of both biogenic and secondary aerosol formation. A good correlation was also observed between EC and OC (R2 = 0.81) indicating their common origin. PMF has identified industrial dust (18.2% of PM10), vehicular emission (26.5% of PM10), bio mass fuel (24.3% of PM10) and re-suspended dust (4.6% of PM10) as major sources of PM10 in urban environment of Lahore.