Source characterization of PM10 and PM2.5 mass using a chemical mass balance model at urban roadside Original Research Article

The 24-h average ambient particulate matter (PM10 and PM2.5) concentrations are sampled concurrently during November 2008–April 2009 at a busy roadside in Chennai City, India. The elemental (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sr, Te, Tl, V and Zn) and ionic (Na+, NH4+, K+, Ca2 +, Mg2 +, F−, Cl−, NO2−, NO3− and SO42 −) composition of PM10 and PM2.5 are determined using an inductively coupled plasma-optical emission spectrometer (ICP-OES) and an ion chromatograph (IC), respectively. The emission inventory at the study area is also carried out to identify the likely PM emission sources.The U.S. EPAʹs-CMB (chemical mass balance) version 8.2 is applied to identify the source contribution of ambient PM10 and PM2.5 concentrations at the study area. Results indicated that diesel exhausts (43–52% in PM10 and 44–65% in PM2.5) and gasoline exhausts (6–16% in PM10 and 3–8% in PM2.5) are found to be the major source contributors at the study site followed by the paved road dusts (PM10 = PM2.5 = 0.–2.3%), brake lining dusts (0.1% in PM10 and 0.2% in PM2.5), brake pad wear dusts (0.1% in PM10 and 0.01% in PM2.5), marine aerosols (PM10 = PM2.5 = 0.1%) and cooking (~ 0.8% in PM10 and ~ 1.5% in PM2.5).