Abstract for presentation at 14th IUAPPA World Congress

The Tennessee Valley Authority (TVA) in cooperation with the state of Tennessee operated a continuous fine particle (PM_2.5) monitor at a rural site to help establish background PM_2.5 air quality. Although this monitor usually measures levels substantially less than its more urban counterparts, it recorded unusually elevated PM_2.5 levels from September 5-15, 2005. TVA and Tennessee conducted a case study analysis of this unusual event/episode considering the relationship between PM_2.5 levels and various meteorological variables and potential local, regional and long range emissions sources. It is suspected that early morning inversions and stagnant conditions throughout the day associated with the high pressure system hindered the transport and dilution of PM_2.5 levels caused by emissions from local agricultural burning, as well as long range transport of smoke from fires occurring in Idaho during the first half of the period. One concern of this episode is how a few elevated PM_2.5 levels occurring in a relatively short time period influence the annual average for the site. The recently revised US PM_2.5 daily standard also means that episodes like this will take on even more importance in determining compliance.
To better characterize local sources, TVA and Tennessee agreed to conduct additional monitoring - including filter based sampling - during August and September 2006. The results of this study, focusing on the impacts of agricultural burning on ambient PM_2.5 mass concentrations and chemistry, will be presented at the 14th IUAPPA World Congress in September 2007.