The government thinks radioactive industrial waste from China is responsible for a recent sulfur stench that has plagued hundreds of Florida homes. Demand for Chinese drywall spiked during the housing boom, but federal regulators believe the drywall contained phosphogypsum, a banned waste byproduct that features prominently in Chinese construction. When used in drywall, the probable carcinogen can corrode “air conditioners, mirrors, electrical outlets and even jewelry.”