Is Trash about corruption?

Trash, a 2011 young-adult novel by Andy Mulligan, takes place in the Philippines, one of the places where the author spent time as a volunteer English teacher. He saw first-hand the harsh reality of entire families who eke out a living as trash pickers, selling whatever they may be able to salvage in the heaps of refuse near their dwellings. Children born into this life often work hard sorting through the literal mountains of trash to help their families stay alive.
Although corruption of some form inevitably lies behind all types of social injustice, the storyline of Trash revolves around the adventures of three very poor trashpicker children, Raphael, Gardo, and Rat, who one day find a wallet with some money in it, a folded map, and some keys—items that will lead them through a page-turning adventure.