Piles of computer waste in Guiyu, the Chinese computer waste centre. The Basel Convention, the 1989 United Nations environmental treaty, calls for a total block on the export of all hazardous waste from rich countries to poor for any reason, including recycling. The United States is the only developed country that has failed to ratify it..Every year Guiyu takes in more than a million tons of computer waste, imported primarily from the United States, Japan and South Korea. About 40,000 local farmers and 100,000 migrant workers make their living from the e-waste, which contains toxic ingredients such as lead, beryllium and mercury. The workers risk catching respiratory and skin diseases, eye infections and even cancer.