By Daniel Beloumou Olomo / AFP Sheltered from the harsh central African sun by a patched-up parasol, Ismael Alioum rummages through piles of electronic waste, gleaning useful components and high-value metals from circuit boards and switches. Sheltered from the harsh central African sun by a patched-up parasol, Ismael Alioum rummages through piles of electronic waste, gleaning useful components and high-value metals from circuit boards and switches. The scrap-metal district of Yaounde, the capital of Cameroon, is in full swing as artisanal workers scavenge through discarded items and sell their…