Household problems ranging from corroded plumbing to serious skin rashes all are coming from the same source—China—according to experts in the United States and in other countries. For many Americans living in as many as 100,000 new homes built during the recent housing boom, the drywall contains chemicals that, when exposed to heat and humidity, give off fumes that not only smell bad (like rotting eggs) but also is capable of corroding copper pipes, tarnishing jewelry and making people sick. This particular drywall was imported from China by construction companies because it was abundant and cheap. It is believed that as much as 500 million pounds of the toxic compound wound up in the United States, including in newly built homes in the Southeast after Hurricane Katrina.