The German environment ministry says an unknown, highly toxic substance is responsible for the mass die-off of wildlife in the Oder river. High levels of mercury have also been found in the river. Polish Prime Minister Mateusz Morawiecki says the river will take years to "return to normal".
The German environment ministry says thatan unknown, highly toxic substance is responsible for the mass die-off of wildlife in the Oder river. High levels of mercury have also been found in the river. Polish Prime Minister Mateusz Morawiecki saysthat the river will take years to "return to normal".
