1. U.S. Environmental Protection Agency, Office of Research and Development, National Homeland Security Research Center, Research Triangle Park, North Carolina 27711, United States
2. Battelle Memorial Institute, 505 King Avenue, Columbus Ohio 43201, United States
3. U.S. Environmental Protection Agency, Office of Land and Emergency Management, Chemical, Biological, Radiological, and Nuclear Consequence Management Advisory Division, Research Triangle Park, North Carolina 27711, United States