UN plastic agreements-from the deep sea to the brain

Plastics, in a still recognizable size or in the finest particles, can now be found in every corner of the planet. From deep sea to the polar areas, in the water, in the ground, in air and in numerous organisms, including in the human body. Plastic are always found in the autopsied stomachs diluted, but also sea turtles and seabirds hold plastic parts for food, injure themselves on their sharp edges or starve because the stomach is so filled, but the substance does not nutritiously. It is also widely known that marine animals such as turtles and seals get tangled and underlie in lost networks and other plastic parts. But all of these are only the most visible consequences of the increasing plastic pollution of the planet. Most of the effects of plastics in the environment and on organisms take place in a very small way. And many are still hardly researched.

The miracle material plastic has only been produced massively since the 1950s – the amount of less than two million tons in 1950 to over 400 million. Since the fabrics obtained from petroleum are hardly decomposed, but only further chopping, they accumulate in the environment. In which quantities can only be roughly appreciated. In a just published article in the medical journal “The Lancet”, there is talk of eight billion tons of plastic waste that can be found on Earth today. The Geomar Helmholtz Center for Ocean Research estimates that more than 100 million tons of plastic waste have so far reached the sea, of which only less than one Percent drives on the surface of the sea, the majority of somewhere between the surface and the seabed.

It is even less known to the plastic pollution of floors, but at the Thünen Institute you assume that the contamination on land is even higher than that in the oceans. Sources are agriculture itself, which uses more and more foils, plastic residues in sewage sludge and compost as well as tire abrasion.

The smaller the particles, the longer you can stay in the air. Researchers from the Max Planck Institute for Meteorology have calculated that microplastic particles can remain in the atmosphere for up to one year and thus spread over the world. The burden on interiors and vehicles should be far greater than outdoors: Researchers from the University of Toulouse Study 528 microplastic particles per cubic meter of air measured in living rooms and 2238 particles in cars.

Plastic pollution is currently faster than that its extent and its effects could be researched. For this reason, the planetary limit for pollutants and plastic in the environment was declared exceeded in 2022. “The increasing production rate and the release of larger quantities and a higher number of new substances with different risk potentials exceed the ability of society to carry out safety -relevant evaluations and surveillance,” commented the Stockholm Environment Institute involved in the study at the time.

Plastic is not the same as plastic

What makes the risk assessment so complicated: plastic is not the same as plastic, but is divided into different varieties such as polyethylene, polypropylene, polyvinyl chloride, polyethylenterephthalate etc. Plastic can also contain other pollutants, such as bisphenol A, which in the body looks similar to hormones. Pollutants can adhere to microplastics in the environment, as well as pathogens. In connection with plastic, bacteria and viruses can partially survive in sewage treatment plants. And whether and how plastic is taken up by organisms plays a crucial role in the size of the particles. A risk of human health is likely to be micro and nanoplasty.

Microplasty means plastic particles that are less than five millimeters, but even larger than a micrometer, nanoplasty is correspondingly smaller than a micrometer, i.e. 0.001 millimeters. The particles get into the body with drinking water, food or with the breath. The study authors from the University of Toulouse estimate that adults could inhale around 68,000 plastic particles a day. Eleonore Fröhlich, who is researching nanoparticles at the Medical University of Graz, among other things, says that most of the plastic still gets into the body via stomach and intestines.

Brains the most stressed

In a research work from 2021, the plastic quantity that people absorb every week is estimated at 0.1 to 5 grams – the latter would correspond to the weight of a credit card. Karsten Grote, cardiologist at the University Hospital Gießen and Marburg, who also researches the effects of plastic, assumes that this quantity is somewhat exaggerated, but the weekly recording is still in the gram area. The fact is: plastic has been detected in the bodies of late people and people living in the blood. Of all things, according to a published in “Nature Medicine”, according to a one in February 2025 Study significant plastic quantities. The research team around Matthew Campen studies had examined the organs of the deceased on accumulated micro and nanoplasty. It was not only that the brain samples contained a lot of plastic, and samples from 2024 were also more stressed than that from 2016, which indicates a growing environmental impact.

As early as 2023, researchers in the mouse experiment were able to prove that the smallest plastic particles could pass the blood-brain barrier. So far, you don’t know what exactly the plastic does in the brain. Lukas connoisseur, pathologist at the Medical University of Vienna, suspects that, as in the blood, it contributes to inflammatory reactions. The plastic could deposit as so -called plaques on the walls of veins and arteries. A work published in 2024 in the “New England Journal of Medicine” finds a correlation of arteriosclerotic plaques containing plastic, and the frequency of heart attacks and strokes. However, the study authors themselves notice that socio -economic data and other risk factors for cardiovascular diseases have not been recorded.

The smaller, the more dangerous

According to Lukas connoisseurs, the smallest particles are probably the most dangerous, because they have the largest surface in relation to the crowd: “The particle surface is very crucial for what can then bind to the particles, for example cholesterol molecules or whatever it makes it easier to get into the body in organs.” Can accumulate tumors, more than in the surrounding healthy tissue. An effect of micro and nanoplasty on growth and spread of cancer cells is therefore conceivable, but has not yet been proven. It is also unclear whether and how the plastic absorbed can be broken down again in the body. Immunzellen could play a role here, but in their function they could also be impaired by the plastic.

According to the current state of research, it is clear that human and animal organs contain plastic, and it can be assumed that this amount has increased in recent decades. So how can you react to an increasing stress, the effects of which have so far only been guessed at? If plastic particles are harmful, then limit values for food, drinking water and breathing air should actually be determined. Limit values can only be defined if I know which plastic particles, which combinations of plastic particles and what sizes are, for example, hazardous to health, “says Lukas connoisseur.

However, all evidence suggests that further spread plastic in the environment must be avoided.

The amount of plastic that people absorb every week is estimated at 0.1 to 5 grams.

–