I was part of a team that recently discovered human-made pollutants in one of the deepest and most remote places on Earth – the Atacama Trench, which goes down to a depth of 8,000 meters in the Pacific Ocean. The presence of polychlorinated biphenyls (PCBs) in such a remote location emphasises a crucial fact: no place on Earth is free from pollution.
PCBs were produced in large quantities from the 1930s to the 1970s, mostly in the northern hemisphere, and were used in electrical equipment, paints, coolants and lots of other products. In the 1960s, it became clear they were harming marine life, leading to an almost global ban on their use in the mid-1970s.
