Spokane, WA : U.S. Dept. of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Spokane Research Laboratory, 
Title from title screen (viewed on July 18, 2008). and "July 2000."
Mode of access: Internet at the National Institute for Occupational Safety and Health web site. Address as of 7/18/08: http://www.cdc.gov/niosh/mining/pubs/pdfs/ri9653.pdf; current access available via PURL.