While the use of polychlorinated biphenyls, more commonly known as PCBs, has been banned for more than a decade, the chemical pollutants continue to threaten animals at the top of the food chain. A new study published in the journal Science predicts that current concentrations of PCBs can lead to the disappearance of about half the world’s population of killer whales within the next three to five decades.
PCBs have been used around the globe in electrical components and plastics since the 1930s. More than one million tons of the pollutants have been produced. Previous research has shown that PCBs are toxic to animals, shown to impair reproduction, disrupt the endocrine and immune systems, and increase cancer risk.
Several countries began banning the use of PCBs in the 1970s and 1980s. In 2004, more than 90 countries committed themselves to phase out and dispose of the large stocks of PCBs through the Stockholm Convention.
However, PCBs are slowly decomposed in the environment and continue to have detrimental effects on a number of animals.
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