1. National Council for Air and Stream Improvement, 600 Suffolk Street, Lowell, MA 01854, USA E-mail: jpalumbo@ncasi.org
2. Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, USA E-mail: linfield.brown@tufts.edu
3. National Council for Air and Stream Improvement, Western Michigan University, 4601 Campus Drive, A-114 Engineering Building, Kalamazoo, MI 49008, USA E-mail: van.maltby@wmich.edu; laurel.eppstein@wmich.edu