The Rio Huaypetue mine is a large open-pit gold mine in south-eastern Peru, inside the Cusco Region and close to the border with the Madre de Dios and Puno regions.
According to some reports children as young as 12 work in the mines, with government officials describing slave-like conditions and estimating that in certain sectors, 50 percent of the workers are boys under 18.
Working conditions are hard with 10- to 12-hour days and many workers suffering from malnutrition.
Children exposed to the substance suffer the risk of brain damage.
The sediment and runoff from the mine can be traced for hundreds of kilometers along the river.