1. Air Resources Division National Park Service Lakewood Colorado 80225 USA
2. RTI International 3040 Cornwallis Road Research Triangle Park North Carolina 27709 USA
3. US Environmental Protection Agency Western Ecology Division National Health and Environmental Effects Research Laboratory Corvallis Oregon 97333 USA
4. Department of Biology Kenyon College Gambier Ohio 43022 USA
5. US Environmental Protection Agency Office of Air and Radiation Office of Air Quality Planning and Standards 109 TW Alexander Drive Research Triangle Park North Carolina 27709 USA
6. US Environmental Protection Agency Office of Research and Development National Center for Environmental Assessment 1200 Pennsylvania Avenue NW Washington D.C. 20004 USA
7. US Environmental Protection Agency Office of Water 1200 Pennsylvania Avenue NW Washington D.C. 20004 USA