Scientists have discovered a high concentration of toxic chemicals in the brains of whales washed ashore in Fife, Scotland.
A group of grinds hit the beach between Anstruter and Pittenweem on September 2, 2012. Of the 31 mammals, only 10 were returned back to the sea, while the rest died. Among them there were 16 females and 5 males. The tests were carried out by experts from the University of Aberdeen and the Scottish Society for the Study of Marine Animals. Scientists have found mercury in such high doses that it can cause serious damage to the nervous system in humans, as well as the toxic substance cadium, which can enter the brain through the blood. According to the researchers, mercury and cadium could not disorient the animals and force them to wash ashore, but could provoke high levels of stress in them.
An article published by scientists in the journal Science of the Total Environment points to a clear link between high levels of toxins and the age of mammals: it is assumed that increasing the concentration of harmful substances increases their lifespan. It is said that this species of marine animals is less susceptible to the harmful effects of mercury than humans, but the possibility that its presence in the body could affect the disorientation of animals and knock them off course cannot be completely ruled out.
Analytical chemist Dr. Eva Krupp of the University of Abendin, after analyzing whale body samples with her students, says: “We have collected an unprecedented amount of samples from all vital organs, including the brain. As a result, we can see for the first time the long-term effect of how environmental pollution affects mammals. This group of whales gives us unique, new data because we can observe the impact on a large number of whales of the same species based on their age.”
In addition, the analysis of the samples showed that the mercury content in the whales' organisms increases depending on their age, which ranged from one to 36 years. Mammals over the age of 9 have been found to have high concentrations of mercury in the brain, and in three of them, the level of the substance reached the limit when humans develop severe damage to the nervous system.
Dr. Krupp adds: “Although animals have a defense mechanism in the form of selenium, which is designed to reduce the level of harmful substances, it was found that in most older mammals, selenium synthesis was not possible for essential proteins. This suggests that the longer whales live, the more difficult it is for them to cope with the effects of toxic substances.