Microplastics are a serious hazard in particular for the marine ecosystem. And it is not just an issue of marine pollution with a material which is extremely durable and which takes hundreds of years to be broken down. The impact on marine organisms such as seals, fish and mussels, which ingest microplastics passively or via their food, is also a problem. According to an article on nature.com, perhaps the simplest form of damage, at least with regard to marine organisms, could be organisms swallowing microplastics of no nutritional value and therefore not eating enough food to survive.

Based on our food chain, it stands to reason that microplastics can be found in the human body. This has also already been confirmed by recent scientific studies. Research in this area is still in its infancy, so little is known at present about the possible health impacts on humans. Researchers believe that the concentrations of microplastics and nanoplastics in the environment are currently too low to be harmful to human health. Recent articles do show some harmful effects of the plastic particles in mice, but these results cannot be transferred to humans, due to differences in immune system, blood circulation, and microplastics intake. Additionally, even studies which find a statistical correlation between microplastics in the brain and health diseases, are not able to prove a causal relationship.

We need to make a distinction here again between primary and secondary microplastics. Secondary microplastics mostly end up in the oceans due to plastic waste being disposed of incorrectly. Every one of us can play a part in preventing this by collecting plastics and disposing of them correctly. Primary microplastics, meanwhile, are released first and foremost due to the use of products containing plastics and much less so also during production, shipment and recycling. According to the IUCN, primary microplastics find their way into the oceans via four main pathways:
•    Direct losses into the ocean, e.g. marine coatings
•    Wind dispersion, e.g. particles from car tyre abrasion
•    Road run-off, e.g. of road markings
•    Wastewater treatment facilities, e.g. fibres from household laundry

The best-known use is their exfoliating effect. Particles smaller than 60 µm are less suitable – the ideal size is around 420 µm. The plastics used are polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyamide (PA), polytetrafluoroethylene (PTFE, Teflon), polymethyl methacrylate (PMMA), polystyrene (PS), polyurethane (PUR) and various copolymers (UBA microplastics study).

According to a study conducted by the University of Münster which examined 38 different mineral waters in single-use and reusable plastic bottles, glass bottles and beverage cartons, there are traces of microplastics in reusable bottles made of both plastic and glass. Fewer particles were found in single-use bottles and beverage cartons. The study author Darena Schymanski assumes this primarily has something to do with the cleaning needed in the case of reusable bottles. Tap water has the lowest level of microplastics. More information on microplastics in drinking water is available from the WHO.

There are various options here:
•    You can identify soluble plastic compounds which are harmful to the environment, for example microplastics in cosmetics, detergents and cleaning products, by looking for names such as acrylate, carbomer, crosspolymer, copolymer and polybutene in lists of ingredients. Tip: There is a ban on soluble plastics being used in certified natural cosmetics and ecological cleaning products.
•    Do not use synthetic textiles (polyester, nylon or acrylic): natural fibres such as cotton, wool, silk and linen are biodegradable. In addition, a short washing cycle at a low temperature and a full load of washing is better for synthetic textiles.
•    It is also important that plastics be disposed of correctly so that they remain in the loop. Tip: Collect plastic packaging you find in the environment and dispose of it.
•    Use public transport more to reduce tyre wear.

Scientists have been studying microplastics for about a decade, but the field is still developing due to the lack of standardized definitions, testing methods, and measurement tools, which complicates comparing results across studies. Microplastics vary in shape, size, and chemical composition, and their behavior differs in various environments such as air, water, soil, or the human body. Consequently, data gaps persist, particularly regarding long-term impacts on ecosystems and human health. Additionally, most tests have been conducted on animals, which presents reasonable differences compared to humans.

While studies have confirmed the presence of microplastics in human blood, mothers' milk, lungs, and even placental tissue, it's not yet clear how long they remain in the body or whether they accumulate over time. The body may be able to eliminate some particles, especially larger ones, through normal biological processes—but smaller particles (especially nanoplastics) may persist longer and potentially cross cell membranes. More research is needed to understand the dynamics of microplastic retention, accumulation, and elimination.

Nanoplastics are even smaller than microplastics - typically under 1 micrometer in size. Because of their size, they can penetrate biological membranes and potentially enter organs and tissues, which makes them an area of increasing concern for both environmental and human health. Research into their behavior and impact is ongoing.

Not necessarily. Many so-called “biodegradable” plastics only break down under specific industrial composting conditions. If they end up in the ocean or landfill, they often degrade very slowly and may still form microplastics during breakdown.