CMB source apportionment during REVEAL

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