The poisonous chemical Polychlorinated biphenyl (PCB) has long been banned, but it continues to leak into the ocean. A new study has revealed that the chemical continues to pose a threat, particularly to the apex predators of the sea.
The new study published in the journal Science suggests that at least half of the killer whale population in the world may be wiped out before the end of the century due to chemical pollution in the ocean.
PCBs were once widely used in the production of carbonless copy paper and as coolants before they were discovered to be carcinogenic and toxic.
The production of the chemicals was halted in the United States in 1979 under a 2001 international treaty. Unfortunately, PCBs are still used in many parts of the world. The terms of the Stockholm Convention state that the chemical is not due to be completely phased out until the year 2025.