Located 30 kilometres from Dakar (Senegal), Mbeubeuss is an unauthorised dump site, where each day, 350 rubbish trucks dump about 1,300 tons of household waste, from Dakar and environs. It is an ecological bomb: since its creation in 1968, the dumpsite has been growing and increasingly gaining ground, polluting surrounding waters, soils and the environment. But Mbeubeuss is also a source of income for about 1,800 people who work in and earn their living from the dump site. Photo: Fabrice Monteiro / Prix Pictet

The 12 Prix Pictet photography prize finalists - in pictures