CMB SOURCE APPORTIONMENT DURING REVEAL

Source contributions to PM(2.5) aerosol measured at Chilliwack and Pit t Meadows in the lower Fraser Valley, B.C., Canada, during the REVEAL study, were estimated using chemical mass balance (CMB) receptor model ing. On average, motor vehicles accounted for 34 and 43% of PM(2.5) at Chilliwack and Pitt Meadows, respectively Secondary sulfate and secon dary nitrate were the next most significant PM(2.5), components, accou nting for 25 and 27%, respectively, at Chilliwack, and 27 and 12%, res pectively, at Pitt Meadows. Geological material accounted for 3 and 5% of PM(2.5) at Chilliwack and Pitt Meadows, respectively. Marine aeros ol accounted for 3 and 5% of PM(2.5) at Chilliwack and Pitt Meadows, r espectively A significant contribution of wood smoke was estimated for both sites: 8% at Chilliwack and 9% at Pitt Meadows.