Kim Kyong-ho, U.S. Army Corps of Engineers Far East District Geotechnical Branch chemist, analyzes an asbestos sample collected from an U.S. Army Garrison Yongsan-Casey building through a microscope. According to the U.S. Environmental Protection Agency, asbestos was used in many types of home building products and insulation materials until the 1970s. (U.S. Army photo by U.S. Army Corps of Engineers Far East District)