17:50 12 February 2016
A pod of 21 stranded whales that died on a Scottish beach had high levels of toxic metals in their brains that could have messed up their navigation system.
Tests performed on long-finned pilot whales that beached in Fife in 2012 reveal the presence of mercury and cadmium build-ups, which levels are high enough to cause neurological damage even in humans. The whales were stranded on a beach between Anstruther and Pittenweem on September 12, 2012.
Dr Eva Krupp, who collected and analysed samples from the whales together with PhD students Cornelius Brombach and Zuzana Gajdosechova, said: “We can see clear evidence that mercury is being transported through the blood stream to all organs where it accumulates over the lifespan.
“As well as an increased concentration of mercury in the brain as the whales become older, we see a similar effect with cadmium, which has not been previously reported.
“It is known that cadmium can penetrate the blood brain barrier in the new-born or developmental stages but it was not thought to do so in adults.
“Our findings are significant because we can demonstrate for the first time that cadmium is in the brain tissue and that its levels increase with age.
“Although the body has a natural defence mechanism in the form of the element selenium, which detoxifies these harmful chemicals, we found that the majority of selenium is not available for the synthesis of essential proteins in older animals.
“This indicates that the longer mammals live, the less able they may be to cope with the toxic effects.”