Toxic mud from the Samarco tailings dam disaster reached the Atlantic Ocean on 22 November
Arsenic and mercury have been detected in the waste.
Allegations have been made that the disaster was the result of industry and government negligence.
The disaster is extracting a mounting financial toll from BHP Billiton.
The Brazilian government has filed a civil suit against Samarco, Vale, and BHP Billiton.
A Brazilian judge has now frozen the assets of BHP Billiton and Vale.
To survive, Indigenous Peoples impacted by the disater have called for enlargement of their territory.
The United Nations has called on Brazil to improve safe water access.
Find our previous update here.