1. Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221-0071.
2. Corresponding author: Department of Civil and Environmental Engineering, University of Cincinnati, P.O. Box 210071, Cincinnati, OH 45221-0071. Phone: 513-556-2987; Fax: 513-556-2599; E-mail: George.Sorial@uc.edu.
3. Ecosystems Research Division, National Exposure Research Laboratory, US EPA, Athens, GA 30605.