The orca whale populations in Europe are at risk due to man-made poisonous chemicals that have been banned decades ago, according to ecologists.
In the study – published Thursday (Jan. 14) in the journal Scientific Reports – researchers from the United Kingdom, Ireland, Portugal, Spain and Slovenia collected samples from 1,000 killer whales (Orcinus orca), porpoises, and dolphins. They found that all those animals were being harmed by a synthetic organic chemical compound called polychlorinated biphenyl (PCB).
Stricter rules for disposal of items that contain polychlorinated biphenyl are needed, because they could help save the orca whale populations around areas of Europe, the researchers said.
Polychlorinated biphenyls (PBCs) were once used in building materials and plastics, but they were banned about thirty years ago. However, these materials can still be released because of improper disposal of construction material, electrical equipment, and old paints from the 1980s.
Dr. Paul Jepson, lead author of the study and a specialist wildlife veterinarian at the Institute of Zoology – the scientific research division of the Zoological Society of London (ZSL), said that the poisonous chemicals are getting into estuaries and rivers from landfills, and will eventually be carried into the marine environment as well. In industrialised regions of Europe, killer whales are at high risk of extinction, Dr. Jepson stated.
It is only a matter of time until PBCs pass up the food chain and reach the dolphin and killer whale populations, according to the researchers. Experts urge for stricter rules on how materials containing polychlorinated biphenyls are disposed of.
The study results showed that some of the highest levels of PBCs across the globe were found in marine animals off the coasts of the United Kingdom, Ireland, Portugal, Spain and Slovenia.
Animals off the coast of the United States had lower levels of polychlorinated biphenyls, possibly because the U.S. banned the poisonous chemicals almost ten years prior to the European community.
Unfortunately, polychlorinated biphenyls are known to be quite difficult to destroy because they are resistant to chemical attack, heat, and natural degradation. Researchers from the University of Calgary found (in 2013) a way to destroy polychlorinated biphenyls in soil with the help of UV (ultraviolet) light.
Even so, to reduce the risk of polychlorinated biphenyls entering the marine environment and ultimately killing off Europe’s killer whales, the authors of the new study say that stricter restriction on how products containing PCBs are stored may help with this problem.
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