A
mbient PM
2.5 (particulate
matter
![](/i<font color=)
mages/entities/le.gif"> 2.5
![](/i<font color=)
mages/entities/
mgr.gif">
m in aerodyna
micdia
meter) sa
mples collected at a rural
monitoring sitein Bondville, IL on every third day using Interagency Monitoringof Protected Visual Environ
ments (IMPROVE) sa
mplerwere analyzed through the application of the positive
matrixfactorization (PMF). The particulate carbon fractionswere obtained fro
m the ther
mal optical reflectance
methodthat divides particulate carbon into four organic carbon,pyrolyzed organic carbon (OP), and three ele
mental carbonfractions. A total of 257 sa
mples collected betweenMarch 2001 and May 2003 analyzed for 35 species wereused and eight sources were identified: su
mmer-highsecondary sulfate aerosol (40%), secondary nitrate aerosol(32%), gasoline vehicle (9%), OP-high secondary sulfateaerosol (7%), seleniu
m-high secondary sulfate aerosol (4%),airborne soil (4%), aged sea salt (2%), and diesel e
missions(2%). The co
mpositional profiles for gasoline vehicleand diesel e
missions are si
milar to those esti
mated inother U.S. areas. Backward trajectories indicate that thehighly elevated airborne soil i
mpacts were likely caused byAsian and Saharan dust stor
ms. Potential sourcecontribution function analyses show the potential sourceareas and pathways of secondary sulfate aerosols, especiallythe regional influences of the biogenic as well asanthropogenic secondary aerosol.