For the first time measuring the level of organic pollutants in the deepest submarine trenches (including Mariana Trench), the researchers found a  large number of toxic chemicals accumulated in the organisms of the habitants, reports Lenta.

The researchers studied the level of accumulations of organic pollutants in amphipods who live  at the depth of 7-10 thousand meters. Previously, such tests were conducted in up to 2 thousand meters deep waters.

It turned out that in Mariana Trench the accumulation of polychlorinated biphenyls (PCB) is two times higher than it is in deltas of China's two polluted rivers . Scientists think that the high level of PCB  in Mariana Trench is determined by nearby Chinese industrial districts that produce plastic as well as the US military base near Guam.