1. Environmental Engineering Research Centre, School of Planning, Architecture, and Civil Engineering, Queen's University of Belfast, Belfast BT9 5AG, Northern Ireland, U.K., Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6038, and Faculty of Earth Systems and Environmental Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Korea