Scientists were surprised and alarmed to find extraordinary amounts of banned chemicals in the deepest parts of the ocean, While many things that the deepest part of the oceans are safe from pollutants brought about by humans, a new study shows that this is not so.

BBC reports that pollutants like polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other pollutants were found more than 10 kilometers below sea level in the Mariana Trench. These types of chemicals were actually banned in the 1970s.

A team from the University of Newcastle, led by Dr. Alan Jamieson, took the sample from the fatty tissue of a type of crustacean called amphipods. The amphipods look like shrimps and live in the deepest waters found on the planet. Samples for the study were taken from the Mariana Trench and the Kermadec.

In the study that was published in the journal Nature Ecology and Evolution, Jamieson said that the levels of pollutants found in the samples were similar to the contamination in Suruga Bay, Japan. That area is known as a very industrial zone and is one of the most polluted places in the northwest area of the Pacific.

The Independent UK says that the persistent organic pollutants or POPs has been banned for 40 years. These were used in many products such as electrical insulators and flame retardants. It is estimated that around 35% of the chemicals may have leaked into the open ocean since it was banned.

The chemicals may have reached the bottom of the ocean as plastic may have sunk into the sea. Or it may have been consumed by other animals which went down and were eaten by the creatures found at the bottom of the sea.

Jamieson says that there is no conclusion yet on what the findings could mean for the wider ecosystem. Further research and study are needed to know what challenges may occur due to the findings.