Figure 1 shows average handset mass and gold content from 1992 to 2004. The data series have been synthesized from a variety of sources [8, 27, 49, 53, 55]. It shows a reduction in hand set mass of 66% and in gold content of 60% over this period of time. Handset mass has leveled off at around 80 g, which is due to consumer preference rather than technical feasibility. Gold content might yet further
decrease. As a result of both trends, the amount of recoverable gold per handset has decreased from around 0.12 to 0.025 g (Fig. 2).