Characterization of fine particle sources in the Great Smoky Mountains area.

A source apportionment study to characterize sources of fine particles in the Great Smoky Mountains area was conducted analyzing ambient PM(2.5) (particulate matter< or =2.5 microm in aerodynamic diameter) speciation data collected at a Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring site. A total of 1442 samples collected between March 1988 and December 2003 analyzed for 30 elemental species were analyzed with the application of the positive matrix factorization (PMF). Eight major sources were extracted: summer-high secondary sulfate (55%), carbon-rich secondary sulfate (16%), summer-low secondary sulfate (2%), gasoline vehicle emissions (13%), diesel emissions (1%), airborne soil (6%), industry (5%), and secondary nitrate (2%). The contributions from the carbon-rich secondary sulfate particles are likely a combination of local and regional influences of the biogenic as well as anthropogenic secondary particles. The compositional profiles for gasoline vehicle and diesel emissions are similar to those identified in other US areas. Backward trajectories indicate that the high impacts of airborne soil were likely caused by Asian and Saharan dust storms. This study would assist in the implementation plan development for attaining the air quality standards for PM(2.5), regional haze rule planning, and source-specific community epidemiology.