Ocean

Micro plastic swells up in rivers with toxic cocktail

The plastic granules in the sediment of rivers, lakes and seas absorb pollutants from its surroundings the researchers demonstrated the HAW Hamburg. Through the food chain, the stuff ends up then back in humans.

Not enough that most waters and hence the sediment on their ground no, contain lots of micro plastic the tiny, maximum 5 mm large particles attract even pollutants such as small magnets and save them. Researchers of the University of Applied Sciences (HAW) in Hamburg now among other things for the sediments from river Elbe, Weser, Trave, the Bodden waters and the North and Baltic Sea have demonstrated that and the conclusion that it is almost everywhere, more than obvious.

In these waters the researchers had sunk equipped with tiny silicone fibers, 50 specially developed pollution collector, mug-large copper fabric, in summer 2015. They were collected again after three months.

Micro plastic shows higher load than the environment

After about a year of expedition and lab work, the researchers have won now findings that not only based their assumptions, but unfortunately even surpass: A success for the research, but not for the general public. The plastic particles actually taking pollutants from their environment the longer they are in the sediment, the more these substances bind them. Three to four times as high as in the surrounding sediment load of plastic granules, and that was after only three months. Thought the researchers had at least a 1:1-enrichment.

Micro plastic swells up in rivers cocktail
Sample from the Rhine at Duisburg: it consists of plastic microspheres, which are up 0.9 millimeters in size between 0.4 to more than 65%. The illustration shows it in 15-facher magnification. Photo: University of Basel

The pollutants, of which here is the speech, is mainly in the Weser and the Elbe Polychloriertes biphenyls (PCBs). The sediments of the port of Stralsund and Rostock fishing port Marie marriage identified in particular polycyclic aromatic hydrocarbons (PAHs) some cancer-inducing substances which for example via diesel products in the water. As a guide: The limit proposed by the EU for products that contain carcinogenic PAH, is 1 mg per kilo.

Biggest load near the Lübeck waste water treatment plant

Also in the Weser estuary and on the Warnow in Rostock, the pollution load was very high. Sad front-runner was the environment of the Lübeck waste water treatment plant with up to 1400 µg or 1.4 mg fluoranthene per kilo silicone, a mutagenic also if swallowed and tumorgener fabric. Whether and how flora and fauna in the waters react to the poison cocktails, also is being investigated in biological test systems.

Polyethylene, such as laboratory test showed HAW Researchers the plastic most commonly used by the industry is also about twice as recording happy like the silicone used in the attempt. Thus, the real levels of pollutants in the micro plastic are probably still even significantly higher than measured. In the water, the plastic piece appears incidentally by waste, which in the course of time and by Sun, wind and waves become brittle and crumble, or directly through small beads that are found as abrasive accessories in a range of cosmetic products. Some manufacturers do not all without now on these additives, but still a long way.

Micro plastic look of a wastewater treatment plant under the microscope:
Micro plastic look of a wastewater treatment plant under the microscope: the plastic fibres washed out of textiles, for example. Also plastic from cosmetics to land in the water. Photo: AWI

The food chain brings the poison back to the people

And the saying “out of sight, out of mind” does not apply here: the pregnant pollutant particles eventually not stay where they are. Worms, clams, and fish consume it with food, which they land by food chain at the end also in humans including poison cocktail, they have pulled in during their stay in water, sand, and silt.

And where are the micro plastic? It is worn over the rivers into the sea. It comes from sewage treatment plants and industrial plants. The problem: The wastewater treatment plants are completely overwhelmed with the micro plastic filters.

plastic swells up in rivers
With the research vessel Aldebaran in the HafenCity in Hamburg when: with the ship, researchers have exposed to the pollutant collector in rivers and bays. The result: micro plastic, which is stored in the sediment, magically attracts toxins. Photo: HAW Hamburg

Partly, there are already studies which amount of micro plastic lead the rivers. Swiss researchers have studied for example the Rhine. And Vienna researchers found more plastic particles as fish larvae in the river Danube.