An Orca whale.
Media playback is unsupported on your device
Video

Banned pollutant PCB threatens Europe's whales

Scientists are warning that a banned pollutant could wipe out Europe's killer whales and dolphins.

The use of the PCB chemical was prohibited from the 1980s but it still exists in the environment.

Rebecca Morelle reports.

Go to next video: Whale remains wash up at Sheringham