Scientists found cadmium in the brains of pilot whales that washed up on Scottish beaches in 2012. Findings showed that the animals absorbed high levels of the toxic metals.

These long-finned adult pilot whales washed up in Scottish shores in 2012. University of Aberdeen chemists found cadmium in all the organs of the animals. The toxic metal was believed to penetrate the brains of unborn and infant whales. For the first time, the study found that cadmium can also pass across adult whales' blood-brain barrier.

Led by environmental analytical chemist Dr. Eva Krupp, the team analyzed the remains of 21 pilot whales that died in September 2012 in Scotland. The team was able to procure an exceptional amount of tissue samples from all of the whales' organs. For the first time, scientists were able to analyze the effects of environmental pollutants to the long-lived animals. The animals were believed to belong in the same group.

The findings also suggested that the concentrations of mercury in the seas could be increasing to a level that could add more toxic stress into the marine mammals. Mercury is used in gold mining and various industries and the practice increased its levels in the seas. Mercury concentrations in whales increase as the mammals age and these animals are known to lead very long lives.

Three whales were about 9 years old or older. The mercury concentrations found in these three whales were even higher than the levels that could result in critical neurological damage in humans.

"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," said Krupp.

Selenium is the body's natural defense against the harmful chemicals. The study found that there wasn't enough selenium for the production of vital proteins in adult animals. Findings suggest that as the toxicity increases with age, the lesser the animals can cope with the effects. The research was published in the journal Science of The Total Environment on Dec. 31, 2015.

"So far, we have no indication that the mercury and cadmium levels in the brain cause disorientation, which in some cases can lead to strandings," added Krupp. However, these marine mammals are largely at risk to develop higher stress due to the increasing toxic metal concentrations in the seas.

Photo: U.S. Fish and Wildlife Service Northeast Region |  Flickr