Perfekte Täuschung: Wasservögel verwechseln Plastik mit Nahrung.
k-online: What risks do microplastic particles represent?
Professor Laforsch: We have proved that a wide range of different organisms from many different tropical levels ingest microplastic. This has been demonstrated with organisms that obtain their food on the surface of the water, with organisms that obtain food from water below the surface and with organisms that live in the sediment. Water fleas eat microplastic particles too, because they confuse them with natural elements of their food – which is the main reason why animals and other organisms ingest microplastic.
k-online: What are the consequences of this mistake?
Prof. Laforsch: Albatrosses, for example – to use a prominent example – confuse plastic floating in the water with small fish or squid. The birds then feed it to their young. The albatross population has decreased by up to 80 per cent in some regions, because young birds have starved to death. Or: turtles confuse plastic bags floating in the water with jellyfish and die eating them. Most animals eat plastic because they confuse it with proper food, because it sticks to proper food or because it is surrounded by organic material (biofilm). It is, however, important to say that the impact of plastic on organisms has not been investigated really well so far.
k-online: Isn’t the plastic simply excreted by the digestive system?
Professor Laforsch: Some organisms excrete everything they ingest. Little plastic balls were, however, used in the relevant studies. It is potentially possible that minute microplastic particles can be absorbed by cells – including human cells – and can be smuggled into the organism. It probably depends on the surface structure of the microplastic particles whether they can penetrate tissue.
k-online: What consequences can be expected if microplastic is absorbed by tissue?
Professor Laforsch: It has been demonstrated that the ingestion of microplastic by bivalvia can lead to inflammatory reactions in the tissue. One of the other properties of plastic is to augment pollutants in water. Studies have shown that the pollutants can damage the livers of fish if they eat contaminated microplastic particles. Additives used in plastics manufacturing can also have toxic or hormonal effects on the organisms that ingest them.
k-online: What pollutants can adhere to plastic particles?
Professor Laforsch: What are, for example, involved are residues primarily of pesticides used in agriculture or persistent organic pollutants (POP). These are substances that are only degraded or transformed in the environment slowly.
k-online: Is it possible to say what type of plastic the microplastic particles are?
Professor Laforsch: There are spectroscopic processes with which the type of polymer can be identified. What are found mostly are polymers of the kind used to manufacture plastic bottles or plastic bags.
k-online: Can it be determined from the microplastic particles what product they come from?
Professor Laforsch: Not really – it is difficult, particularly with small microparticles. In view of the countless plastic bags and plastic bottles that are discarded in the environment, it can, however, be presumed that most of them come from packaging materials.
k-online: Talking about which: what do you think of banning the use of plastic bags?
Professor Laforsch: This is may be a good approach to work with bans. I would, however, encourage every single consumer to make it clear to himself in each individual case whether a plastic bottle, a plastic bag, a plastic multipack is necessary. Anyone who carelessly discards such polymer materials or products or stores them where the wind can blow them into the environment in an uncontrolled fashion, inevitably contributes to the development of microplastic. In the final analysis, the debris ends up back with the consumer at some time or other – on his plate.
