This document was prepared
by the Indoor Environments Division (IED) of the U.S. Environmental
Protection Agency. IED would like to thank the reviewers of this
document who provided many valuable and insightful comments, and the
contractors who provided support during the development of this
document.
EPA would also like
to thank those who provided photos: Terry Brennan (Photo #2, Photo #3A,
Photo #4A, Photo #6, Photo #8, Photo #9); Paul Ellringer (Photo #4C);
Stephen Vesper, Ph.D. (Photo #3B); and Chin Yang, Ph.D. (cover photos,
Photo #4B, Photo #5, Photo #7).