The world’s stock of killer whales is at risk of collapse due to contamination from a chemical product that is now prohibited.
According to a study published in the journal Science, large concentrations of the highly toxic substance polychlorinated biphenyls (PCB) has been found in killer whales.
PCB damage whales immune system and their ability to reproduce, according to the study.
The study shows that PCB is likely to be found in over half of the world’s killer whales. Scientists fear that the population of killer whales near industrial areas will collapse in the next hundred years.
“We knew the PCB level was high, but we were very surprised when we saw how high it was,” says Jean-Pierre Desforges at the University of Aarhus.
PCB was previously used in electrical appliances, paints and other products due to its chemical stability and because it is flame retardant and insulating. But the chemical was banned worldwide 30 years ago.
Nevertheless, PCBs are still available in some parts of the world, and the substance continues to harm due to its long degradation time.
© NTB scanpix / #Norway Today