Morning traffic rattles through the slum district of Payatas in Quezon City, just north of Metro Manila. It is 9am but over 30 degrees Celsius and climbing. A truck pulls over and workers unload the morning’s collection of rubbish, depositing it behind the corrugated iron gates of Joe’s Junk Shop.Payatas is a sprawling shanty town built on a landfill, and these junk shops are an integral part of the local economy. Inside, it is a hive of activity. The space is piled four metres high in parts…