Colombian influencer Sara Samaniego braids her long straight hair, checks her make-up in a mirror, places her phone in the center of a ring light and flashes a big smile for the camera. "Hola mis recicla-amores! (Hello my recycling loves)," the 32-year-old, who is on a mission to teach Colombians how to sort their waste, says to greet her half-a-million Instagram followers. Colombian cities have no public recycling systems. Instead, they rely on informal waste pickers to go through bins and garbage left out for collection to salvage cardboard, glass, plastic and other reusable materials. Across the world, between 20 and 34 million people play a crucial role in environmental protection by collecting and sorting waste recyclables -- dirty, dangerous work for which most are paid a pittance. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES