From the estimated total of 4,600 tons of opium produced in 2002, a potential 460 tons of heroin could be manufactured, although not all opium is converted into heroin.
19. 据估计，2002年的鸦片总产量为4,600吨，因此潜在海洛因制造量将是460吨，尽管并非所有的鸦片都转化成海洛因。