Colombia is a hotspot of mercury pollution from small-scale gold mining. But it's also a testing ground for a new movement to reduce mercury pollution by paying small-scale miners more to use less of the toxic metal.
For producing chemical-free gold, Green Gold miners receive a 15% premium over the international price from an organization called Fairtrade and Fairmined Gold. (Photo: John Otis)
A woman pans for gold at a Green Gold mining site in Choco department in northern Colombia. (Photo: John Otis)
Instead of using mercury to separate gold from ore, Green Gold miners use a soapy liquid made with water and leaves from balsa trees. (Photo: John Otis)