Mud from Brazil dam burst is toxic, UN says

Mud from a dam that burst at an iron ore mine in Brazil earlier this month, killing 12 people and polluting an important river, is toxic, the United Nations' human rights agency said on Wednesday. The statement contradicts claims by Samarco, the mine operator at the site of the rupture, and Samarco's co-owner, BHP Billiton , that the water and mineral waste contained by the dam are not toxic.