Imagine an extremely fine net. For example, the net on a soccer goal is only much smaller. It is so tiny that you can’t even see the mesh under an ordinary microscope. We are talking more about a filter than a net. A coffee filter, a tea filter ‒ these are all basically nets with meshes so fine that we cannot see them. What is smaller than the meshes penetrates; what is bigger stays outside.
Now imagine that the meshes of this incredibly fine net have an edge length of one micrometre. That’s a thousandth of a millimetre. This filter will stop anything larger. But what is smaller, it lets through ‒ for example, particles 999 nanometres in size.
A nanometre is a thousandth of a micrometre, in other words, a millionth of a millimetre or even a billionth of a metre. The ratio of a nanometre to a metre is comparable to that of a hazelnut to the Earth.
A filter structure finer than the smallest particles?
Tuberculosis spores, or even asbestos particles, are so tiny that they can easily penetrate the human alveoli and remain there. Anything even smaller penetrates there as well ‒ logically.
In the case of asbestos, we are talking about particles with a size of 0.5 to 3 micrometres, i.e., from 500 to 3000 nanometres. These particles are thus 500 to 3,000 times larger than a particle of one nanometre in size. So nanoparticles also penetrate into the alveoli when we breathe them in ‒ and also into other regions of our organism when we eat them.
Nanoparticles can even invade the natural spaces of cell membranes and thus implant themselves in the circulation, into all our organs and also into the foetuses of pregnant women.
What would a net need to consist of to stop cubes with an edge length of one nanometre? An even finer material. But there is no such thing yet. What should a net be made of to hold back the finest materials in the world?
There comes a time when downsizing comes to an end. At some point in the microscopy of the whole thing, we reach a size where the structures we see are the molecules themselves. A molecule of haemoglobin, for example, the protein complex of the red blood cell, has a diameter of about 55 nanometres.
This is precisely the problem with nanotechnology: small particles penetrate all filters and meshwork because a filter that stops everything does not yet exist. Because it would also have to stop the particles of which itself consists. The filter structure would be finer than the smallest particles in the world ‒ that would be a paradox.
Tempting applications
Nanomaterials and nano-substances offer exciting applications, including increased strength, lighter weight, improved conductivity, self-healing, self-cleaning and anti-reflection. Nanotechnology represents a lucrative multi-billion-dollar industry, with China leading in innovation.
Nanotechnology represents a lucrative multi-billion dollar industry
We find nano-products in various areas, from food and paints to toothpaste, electronics and medical applications. Nanoparticles even help target specific tissues, like tumour tissue. But they can also infiltrate the environment when not properly managed, as seen with washed-out silver nanoparticles from socks, used to prevent the odour of sweat. The material ends up in sewage plants, rivers, soil and the sea.
The ability of nanoparticles to overcome all barriers, such as the ‘Terminator 3’ made of liquid metal, can also be used to place active substances specifically in tumour tissue, such as lung cancer.
This use of nanoparticles as transport vehicles was demonstrated by researchers from the Helmholtz Centre Munich and the Ludwig-Maximilian-University in Munich (LMU) in 2015. As helpful as this application may be, it reveals one thing: nanoparticles are Trojan horses.
At the same time, nano-materials can form highly toxic combinations with each other, with entirely new modes of action that cannot be foreseen. And in the end, they will have access to all humans, plants and animals – to every cell. And we cannot eliminate them anymore.
What we can learn from the microplastics problem
Classic microplastics in the oceans pose a significant problem. The microplastics’ problem could be largely solved ‒ if we were willing to invest a lot of money and effort. We could collect, filter, recycle and reuse it.
But nano-materials can create highly toxic combinations with unforeseen effects. They’ll inevitably affect all living organisms, and once in circulation, they can’t be collected because they slip through any net or filter.
Nanoparticles don’t decay, regulations fall short
Unlike radioactive isotopes, nanoparticles don’t decay; they remain indefinitely. These ‘nano-risks’ could enter every living organism and ecosystem. Their impact might mirror that of asbestos, a known carcinogen.
Current EU regulations inadequately address nano-material interactions, and testing methods may not be suitable for assessing their risks. Product safety and labelling are also problematic. Products labelled as ‘nano’ only indicate size, not potential risks.
To address these challenges, built-in algorithms for self-destruction and strict disposal controls for nanomaterials are crucial. Robust regulations, controls and liabilities are needed for nano-material development, production, distribution and handling.
Transparent labelling is essential for products containing nanomaterials to inform consumers of potential hazards. It’s vital to act before it’s too late. Nanoparticles may become an invisible threat to all life if not managed responsibly.
Reinhold M. Karner, FRSA, is an entrepreneurship and start-up evangelist, multiple chairman (e.g. AP Valletta), corporate philosopher, entrepreneur, author, university lecturer and fellowship connector of the Royal Society for Arts, Manufactures and Commerce (RSA) for Malta and Austria. This article is a summary of a subchapter of his book Wahre Werte statt schnelles Geld (true values over fast money), published by GABAL Verlag, Germany, 2023.