Around the world, more than 20 million people work in the informal sector known as “waste pickers.” They sort through garbage in trash cans or dumps to find recyclable materials. And, in many countries that don’t have formalized recycling systems, they play an important role in the recycling process. For the first story in our weeklong series on waste pickers, Ridwan Karim Dini-Osman reports on the dangers to health and safety for thousands of waste pickers in a giant landfill in Accra, Ghana. (This story was produced with support from the Pulitzer Center on Crisis Reporting.)