'Shocking' levels of PCB chemicals in UK killer whale Lulu

[nitpicker]

http://www.bbc.com/news/science-environment-39738582

'Shocking' levels of PCB chemicals in UK killer whale Lulu

By Rebecca Morelle
Science Correspondent, BBC News

2 May 2017

From the section Science & Environment

One of the UK's last killer whales was contaminated with "shocking" levels of a toxic chemical, scientists say. The animal, called Lulu, was found dead on the Isle of Tiree in Scotland last year after becoming entangled in fishing lines. But tests now reveal her body contained among the highest levels of polychlorinated biphenyls, or PCBs, ever recorded. The chemicals were banned from the 1970s but are still in the environment.

Researchers now fear that other animals in Lulu's pod also have similarly high levels of contamination. The group, which is found off the west coast of Scotland, is thought to consist of just eight animals.
(snip)

PCBs were used widely in industry during the last century. The manmade chemicals are extremely stable, resistant to extreme temperatures and pressures, and have insulating properties. Because of this they were used in everything from plastics to paints and electrical equipment. But after concerns about the toxicity to humans and animals was raised, a series of bans were put in place around the world from the 1970s onwards.

However the chemicals take a long time to break down and have lingered in the environment, particularly in landfill sites where they can leach into waterways and on into the sea. They then build up in the marine food chain, which means top predators such as killer whales are particularly affected. Dolphins, porpoises are also susceptible.

Levels of PCBs are measured in milligrams per kilogram of lipids (fatty acids) in an animal's body. Dr Brownlow said: "The threshold where we think that there is some form of physiological effect caused by PCBs is around 20-40mg/kg stored within the tissues. Lulu had a level of PCBs of 957mg/kg - and this has put her as one of the most contaminated individuals we have ever looked at." Scientists believe Lulu's age, estimated to be at least 20, may be one reason that the levels of PCBs were so high, because they had built up over the years.

The chemicals have a range of effects. There is evidence that they can impair the immune system. They also affect reproduction, preventing killer whales from bearing young. "That's certainly what we found in the case of Lulu," explained Dr Brownlow. "Having examined her ovaries, there was no evidence that she had ever been reproductively active or had ever had a calf."
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[hunter]

1. This is a really sad story.

Her quality of life was severely impaired and she died young.