Many of them are used in ceramic kilns or bathhouses as fuel, which causes a great deal of air pollution. Tyres are also incinerated in cement plants, and a certain quantity is imported for this puipose (100,000 tons in 2009). At present, there is no centralized or even organized waste collection for this type of waste. The quantity generated annually is insufficient to ensure the economic performance of a dismantling and recycling centre, the sale value of the recovered metals would not support the operating cost. For that reason, this waste is mainly disposed of with household waste, waste pickers collect and disassemble some discarded electrical and electronic equipment and recover the materials of value. An electronic waste recycling project at the Guemassa site involves separating and recovering the precious and non-ferrous metals in electronic boards in order to produce blister copper and gold and silver alloys.