Answer
Loss of water and deforestation, maybe even sinkholes. One more thing, He said pollution, he meant Water pollution due to the metals that seep into the water.
Explanation:
Many Miners in South America are desperate for gold so they take water into the cave to loosen it up, But it turns out that this fact causes deforestation to happen for more mines and sinkholes are caused because of the ground above the cave collapses. The loss of water would take into factor because if there would be so much mines, that water would be overused and eventually may run out.
