Plastic is everywhere. In packaging, clothing, cosmetics and even in the air we breathe. Less visible, but increasingly in the spotlight, are the microscopic particles that emerge from these plastics: microplastics and nanoplastics. They are now being found in water, soil, air, animals and humans. But what exactly are these particles? And what do they do in our bodies?
Robert W. Pol explains how microplastics behave in living organisms, what distinguishes them from nanoplastics and plastic monomers, and what we now know about their potential effects.
What are microplastics, nanoplastics and plastic monomers?
The term ‘microplastics’ has become commonplace, but there are actually three forms of plastic particles that are relevant to people and the environment:
Microplastics
Microplastics are solid, insoluble plastic particles ranging from 0.001 mm to 5 mm in size. They arise primarily through wear and breakdown of larger plastic products, such as packaging, synthetic clothing, car tyres and fishing nets. In the environment, they occur in soil, water and air, as well as in food chains. Due to their size, they are often visible to the naked eye, yet still small enough to be spread unnoticed.
Nanoplastics
Nanoplastics are even smaller than microplastics, with a diameter of less than 0.001 mm. They form when microplastics break down further, but can also be deliberately manufactured, for example for use in cosmetics or industrial applications. Their extremely small size enables them to pass through cell membranes, which may make them more harmful. In practice, they are difficult to detect but are increasingly found in environments with high plastic pollution.
Plastic monomers
Plastic monomers are the chemical building blocks of plastic, such as BPA (bisphenol A), phthalates and styrene. Unlike micro- and nanoplastics, these are discrete, soluble molecules that can be released during the production or breakdown of plastic. They are often used as plasticizers or binding agents in plastics. Monomers can be released through heating, wear or exposure to sunlight and are known for their hormonal effects and potential health risks.
How do these substances enter the body?
People come into contact with microplastics through food, drinking water, air and sometimes through the skin. The particles have been found in tap water, sea salt and indoor air, among other sources. Microfibres from clothing and dust particles from packaging contribute to this.
Microplastics are usually ingested or inhaled. They often remain outside cells and accumulate in tissues, or are taken up by immune cells such as macrophages.
Nanoplastics can enter the body via the digestive tract, lungs or bloodstream. Their small size enables them to pass through cell membranes and spread deeper into the body.
Plastic monomers are absorbed through food, drink or air and spread via the blood. Because they consist of discrete molecules, they can diffuse directly through cell membranes.
The precise consequences of this uptake are still being investigated.
What are the potential health effects?
Although research is still ongoing, initial findings give cause for concern.
Microplastics primarily cause physical damage. They can cause local irritation and inflammation of tissues, for example in the intestinal wall or lungs. Additionally, they can carry harmful substances such as heavy metals or plasticizers, which can be released in the body. Because they are difficult to break down and can remain in tissues for extended periods, there is a risk of chronic immune reactions.
Nanoplastics can pass through cell membranes and accumulate in organs such as the brain, liver and lungs. Research shows they can cause oxidative stress, leading to cell damage or disruption of normal cellular processes such as energy production and gene expression. This can eventually lead to disruptions in organ function, though many questions remain.
Plastic monomers are chemically active and potentially pose the greatest direct health risks. Substances such as BPA and phthalates are known as endocrine disruptors and can affect the functioning of the endocrine system. Known effects include reduced fertility, early puberty, increased risk of hormone-related cancers and metabolic disruption. There is also evidence that some monomers can cause DNA damage.
In short: the smaller and more reactive the particle, the deeper it can penetrate our bodies and the greater the risk of biological disruption.
Why does this matter for the textile sector?
Textile fibres of synthetic origin, such as polyester and polypropylene, are among the largest structural sources of microplastics in the environment. Particularly in applications such as geotextiles in infrastructure and construction projects, wear releases microfibres and chemical additives that can harm soil, water and living organisms. These synthetic residues barely break down and remain in the environment for extended periods, making each application a potential source of microplastic emission.
Zwartz’s alternative
Since 1835, Zwartz has worked with natural fibres such as jute, linen and hemp. These materials are biodegradable and leave no microplastics or harmful chemical residues. This makes them particularly suitable for applications in the geotextile sector, where textiles are used for erosion control and soil stabilization.
Especially at a time when the impact of microplastics is becoming increasingly visible, choosing natural textiles is more than an environmentally conscious decision: it is a practical solution for sectors that want to contribute to more sustainable and cleaner systems, for people, nature and future projects.
Frequently asked questions about microplastics in the body
What are the main sources of microplastics?
Microplastics arise primarily through wear and breakdown of synthetic materials, such as plastic packaging, car tyres and textile fibres. Microparticles can also be released when washing synthetic fabrics or using plastic in construction. Additionally, microplastics are deliberately added to some cosmetics and cleaning products. They then enter the environment via wastewater or air dispersal.
Are microplastics absorbed by the body?
Yes. Microplastics are absorbed through food, drinking water, air and sometimes through the skin. They usually remain outside cells and are stored in tissues or captured by immune cells. Nanoplastics are smaller and can pass through cell membranes, allowing them to spread to organs such as the liver, lungs and brain. Plastic monomers are soluble molecules that circulate in the body via the blood and easily penetrate cells.
Have the health risks been proven?
For plastic monomers, such as BPA and phthalates, the harmful effect is well documented. They can disrupt hormonal balance, affect fertility and increase the risk of certain cancers. Micro- and nanoplastics potentially cause inflammation, cell damage or disruption of cellular processes, but research into this is still ongoing. What is clear is that these substances can accumulate in the body and interact with biological systems.
How does Zwartz address microplastics?
Since 1835, Zwartz has produced technical textiles based on natural fibres such as jute, linen and hemp. These materials are fully biodegradable and leave no harmful microplastics or chemical residues. For example, we offer natural geotextiles for erosion control and ground cover, which distinguish themselves from synthetic alternatives by breaking down completely and safely in the soil. This provides a concrete and reliable alternative for sectors seeking technical textiles without environmental burden.
Download the whitepaper on microplastics here:
