Corrected affiliations and reprint address: Nathan B Fethke, Dan Anton, Joseph E Cavanaugh, Fred Gerr, Thomas M Cook Environmental Health, East Tennessee State University, Johnson City, Tennessee, United States. Physical Therapy, Eastern Washington University, Spokane, Washington, United States. Biostatistics, University of Iowa, Iowa City, Iowa, United States. Occupational & Environmental Health, University of Iowa, Iowa City, Iowa, United States. Reprint requests to: Dr N Fethke, East Tennessee State University, Environmental Health, Campus Box 70682, Johnson City, TN 37614, USA. [E-mail: nathan-fethke@etsu.edu] The editors apologize for listing incorrect information in the original article.