A highly controversial load of toxic waste from Taiwan, which caused deaths and rioting while it was temporarily dumped in Cambodia, may find a permanent home in Idaho. A Taiwanese plastics manufacturer hopes to ship the millions of pounds of mercury-contaminated waste through Seattle or Tacoma, Wash., on its way to a plant in Idaho, where it would be processed and buried. Government regulators say the shipments would not be inherently dangerous, but enviros fear they could set a precedent and make the U.S. a dumping ground for foreign wastes.