Girardot, Steven P., Barry P. Ryan, Susan M. Smith, Wayne T. Davis, Charles B. Hamilton, Richard A. Obenour, James R. Renfro, Kimberly A. Tromatore, and Gregory D. Reed. "Ozone and PM2.5 Exposure and Acute Pulmonary Health Effects: A Study of Hikers in the Great Smoky Mountains National Park." Environmental Health Perspectives 114, no. 7 (2006): 1044-1052.