Chinese made toxic drywall is causing unpleasant odors and possibly leading to electric problems in dozens of homes constructed during the housing boom. Some builders and environmental consultants are investigating whether the drywall is emitting sulfur-based gases that may be corroding air-conditioner coils, computer wiring and metal picture frames. Builders use domestically produced drywall, which is made mainly from the mineral gypsum. During the 2006 housing boom and the scramble for construction material along the Gulf Coast for reconstruction after Hurricane Katrina suppliers began importing drywall from China.