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A dead killer whale (Orcinus orca) found on the Scottish coast had 20 times the expected levels of polychlorinated biphenyls (PCBs) in her system.
Watch this short (one-minute) BBC video about her and then answer the following questions:
1) What do high levels of PCBs do?
2) What were PCBs used for?
2) What were PCBs used for?
3) When were they banned?
4) What does 'leach' mean?
5) What is bioaccumulation?
You can read more about this story here.
Answers below!
1) They weaken an animals immune system, affect the brain and stop whales from reproducing.
2) Everything, from plastics to electrical goods and cement.?
2) Everything, from plastics to electrical goods and cement.?
3) From the 1970s
4) Leach: (with reference to a soluble chemical or mineral) drain away from soil, ash, or similar material by the action of percolating liquid, especially rainwater. (Oxford Dictionaries)
5) Bioaccumulate: (of a substance) become more concentrated inside the bodies of living things (Oxford Dictionaries)
5) Bioaccumulate: (of a substance) become more concentrated inside the bodies of living things (Oxford Dictionaries)
