Jana: My name is prof. Mgr. Jana Kukutschová, Ph.D. and I am from the Faculty of Materials Technology, University of Mining and Metallurgy – Technical University of Ostrava. I am the guarantor of the nanotechnology study programme. As far as my background goes, in the past I studied chemistry and biology and I was a high school teacher. During my master thesis, I became interested in the effect of various chemical substances on living organisms. I developed this topic further in my dissertation and have been working in this field since my studies. Gradually I specialized in the effect of different nanomaterials on living organisms, which was a new topic as nanotechnology gained importance. For about 15 years I have been focused on the risks of nanomaterials and nanotechnology in relation to the natural environment and human health.
Does your position affect you at all? By that I mean do you avoid certain substances if you know what negative effects they can have?
Jana: Leaving aside nanomaterials and focusing on common substances, I try to limit the consumption of smoked meats, for instance, which are known to be potential carcinogens or even already proven to be so. Discussions with colleagues from the National Institute of Health show that some substances are perceived as so-called recognised or conscious risks. This means that the consumers are aware of their negative impact on health. That is why I try to avoid smoked meats and alcohol, because I believe that the joy of life can be found in other ways than through chemical substances.
In the context of different substances and their impact on health, what about nanoparticles? Given their extremely small size (less than 0.00001 cm), is there any general information on their effects on people?
Jana: The effect of nanoparticles on people is an awfully broad topic. If we talk about the health risks of nanomaterials and nanoparticles, it turns out that we still do not know a great deal, and there are still areas where we only suspect what the effects will be, especially with long-term exposure. There already are some studies on short-term exposure, which have all been done on cells, but these conditions are not comparable to the whole human body. So it’s more about caution and being careful about overuse. There was a man called ‘The Blue Man’, who overused colloidal silver. He was using it because he had digestive problems and eventually, he turned blue after using it for a while. That happened because he developed argyria as the silver started to deposit under the skin as a defence mechanism of the body. The doctors advised him to stop. His skin colour never got back to normal completely, it just changed shade 🙂. This was an obvious impact and other effects at the level of various physiological processes are proven, however, the field of nanotoxicology, which is a new science that has emerged within toxicology with the development of nanotechnology, is still full of unknowns. It is presented that the benefits are great, but this goes hand in hand with possible risks, and we still do not have well-defined conditions to handle nanomaterials safely.
How long have we known of nanoparticles? Why do we still not know much about them?
Jana: The extent of nanoparticles was already known in Ancient Rome, where they were used, although they were not called nanoparticles then. For example, they were added to glass, to alter the wavelength of light which changed the colour accordingly. So mankind has known about nanoparticles for quite a long time, even in terms of their applications and uses.
In recent decades, they have been intensively explored, especially with the development of experimental techniques such as electron microscopes, which allow us to better describe, visualise and manipulate these objects to create targeted structures. Thus, the awareness of what nanoparticles look like has been evolving primarily in the last 50 years, maybe even less.
“We still do not have well-defined conditions and recommendations to handle nanomaterials safely.”
What are the main pathways by which nanoparticles enter the human body and what is the difference between nanoparticles and ultrafine particles?
Jana: Nanoparticles, including nanoplastics, can enter the human body through various ways. Nanoparticles are generally distinguished into nanometric particles that can be released as by-products of anthropogenic activities such as transport or industry. These are distinguished from so-called ultrafine particles, which are not intentionally produced. Nanoparticles are considerably smaller than common particles monitored for air quality, such as PM 10 and PM 2.5. Unlike larger micrometric particles that are sedimented by gravity, nanoparticles and ultrafine particles remain in the air longer, increasing the likelihood of inhalation exposure. Inhalation is therefore the most prominent route by which nanoparticles enter the body. Other ways are ingestion (e.g. via foods containing nanoparticles such as pigments) and intravenous administration, which is more targeted, for example in pharmaceutical applications. Skin penetration is considered the least likely route of entry of nanoparticles into the body.
What impacts can be expected from nanoplastics and other nanoparticles that accumulate in animal tissue and what is our current knowledge of their behaviour and environmental impact?
Jana: In the last few years, various studies have begun to show that nanoplastics are released into the environment through the breakdown of microplastics. Yet we still do not seem to have complete and accurate information on how these types of particles behave. The problem lies in the detection of these particles and their characterisation in different environmental samples, be it water or soil. Recently, these types of particles, particularly microplastics, have been found for example in placentas, suggesting that we are probably all exposed to them in a number of ways. We have long been involved in the analysis of biological material specifically in terms of the detection of micro- and nanometric particles. For instance, we have analysed samples of amniotic fluid, where we have found various particulate matter of different compositions, which means that these particles have penetrated the placental barrier. This shows that, as with viruses, the placental barrier is not fully effective in dealing with nanometric particles. (Author’s note: a link to a study Microplastics and additives in patients with preterm birth: The first evidence of their presence in both human amniotic fluid and placenta can be found HERE.)
I’m afraid we still don’t have complete information about the possible impact of nanoplastics. During the last ten years of our collaboration with doctors from various clinics, such as the clinic of otorhinolaryngology or pathology, we have found that there are still many of what we call idiopathic diseases that are considered to have no apparent cause. Still, there is something the organism reacts to, unless of course it is psychosomatic. Over time, we have learned that it always depends on the limits of the methods we use, and this also applies to nanoplastics. The question is what effects nanoplastics can have on individuals. A recent study that came out in June this year showed that plastic-based particles, whether micro or nano, can be released when cutting food on a plastic cutting board. This was published in a reputable environmental science journal. Therefore, there are ways we can influence the level of exposure to micro- and nanoplastics, although consuming water is another matter.
You have been very interested in nanoparticles released from tyres and brake pads. What are the results of the research on nanoparticles released from tyres and brake pads when a car brakes?
Jana: Regarding particles released by abrasion from brakes or tyres of cars, we have been working on this issue for about 15 to 17 years, with the focus on particles produced by brake abrasion. Emissions from so-called non-combustion processes in transport, which are not measured during the state vehicle inspection, have been shown to be a significant source of pollution. Although electric cars are described as “zero emission”, this is not entirely true if they have friction brakes and tyres, which they all do. About 13 years ago, we were the first to describe the nanometric particles released during testing in detail. We tested real hardware, i.e. brake pads and discs on a mid-range vehicle, and found that particles appeared between 5 and 25 nanometers in size, mostly based on soot and various metal compounds. The goal of the research was to describe what is being produced, how we can sample it and characterize it. Another goal is to develop brake pad formulations that have lower emission rates of these nanometer particles, as well as microparticles. Every press of the brake pedal generates abrasive particles, and the goal is for these particles not to be in the sub-100 nanometer size range, but larger and deposited on the road surface rather than in the air.
Over the years, we have found that every time the brake pedal is pressed, abrasion particles are produced, either from the brake plate or from the brake disc. The nature of the emissions and what is released is greatly influenced by the driving style of the driver, not just the materials used in the vehicle. There are two basic scenarios: either you brake hard and larger particles are released, or you brake slowly and the disc does not recool, which increases the temperature and leads to the production of very small soot-based particles. We have provided these results to the various institutions involved in regulating emissions from cars, as emissions are not limited to exhaust gases, but also include emissions from non-combustion processes.
Nanoparticles are commonly released when materials such as plastics, metals, fabrics are used. Is there any material from which nanoparticles are not released, or do we not know of any yet?
Jana: That’s a tricky question. Particles may be released, but we may not be able to capture them with the methods we use. Often it is influenced by these methods, because someone can look at a chimney, see nothing and say that nothing is being released. However, nanometric particles are not visible to the naked eye and we should therefore use other tools to observe them. This also applies to the studies and analysis of different materials using different methods. It is essential to adjust the sensitivity of these methods so that it is precisely the very small particles that can be detected. It is debatable, but it could be possible that abrasion-resistant materials do not release such large amounts of particles. However, I believe that a completely zero release rate is very unlikely. It depends on the conditions in which the material is subjected to wear, because we are talking about wear here. If the material is just hanging in a place and in contact with the airflow, it is a different situation from a joint implant constantly rubbing against a different solid part with each step. This complicates the answer considerably.
In studies looking at nanoparticles (nanomaterial) of titanium dioxide and zinc oxide, which are commonly found in sunscreens, caution is urged because there are still not enough studies. If the nanoparticles of the substances mentioned are not present, then the product is assumed to be safe. Is it possible to say something along the lines of “the smaller the particle the bigger the problem”?
Jana: It is true that smaller particles can be a bigger problem, but it depends on their composition and how they are used. For example, in pharmacology there is a tendency to move away from traditional medicine to nanoforms. This means that the same active ingredient is converted to a nano-sized form, which may change the absorption rate or the behaviour of the drug in the body in a desirable way. In this case, smaller particles may not always be problematic. However, with sunscreens, the likelihood of smaller particles entering the body may be higher. Still, I would not be overly concerned with application to the skin. Of course, there is a difference between putting sunscreen on an adult’s back and putting it on a young child’s face, where even the thickness of the different layers of skin is different. Each case and application should be approached individually and specific materials and their use should be discussed rather than generalised.
As far as the effect on aquatic organisms goes, we are probably talking about freshwater organisms in our case. Titanium dioxide is insoluble, so its effect will be more indirect, for example through UV radiation, which can produce reactive oxygen radicals. These can inhibit the physiological functions of some organisms or, in the worst case, have lethal consequences (author’s note: lethal consequences are those that lead to death or are capable of causing death). For zinc oxide, which is soluble, zinc ions can be released. Zinc is essential and relatively harmless to terrestrial organisms and people, but it is toxic to aquatic organisms. We cannot therefore approach the problem from an anthropocentric point of view only, because us as people, too, are part of the ecosystem and the food chain. I recently read a study that looked at the most important organism for the ecosystem, and it turned out to be bees as pollinators. Therefore, we cannot think only of ourselves.
I was unpleasantly surprised to find that nanoparticles are being applied in nurseries, schools and the like to “kill” viruses and bacteria. Where children come into contact with toys and tools on a daily basis. As a parent, at the very least, I would want to be informed about this and would not approve of such treatment. What, where and how is it actually being applied? What are the risks?
Jana: The application of the nanoparticle sprays involved titanium dioxide in the form of anatase and it is important to distinguish between the different forms such as anatase, rutile or brookite as this affects the impact. According to the company that carried out the application, these nanoparticles were around 5 to 7 nanometres in size, which are very tiny particles. The aim was to achieve a new definition of hygienic cleanliness and to combat childhood morbidity, especially during periods of respiratory illness. We approached the City Council of Ostrava (CR), saying that it could not cope with the increasing number of such offers that came after or during the COVID period. They argued that by not applying these sprays we are not protecting the health of children. However, those who made the decision did not have sufficient information about the behaviour of nanomaterials and were persuaded that this would be the best for the children. Subsequently, the sprays were applied to tables, toys and other items in preschools in the belief that this would reduce sickness. This approach has been implemented in about thirty preschools in the Moravian-Silesian region, specifically in Ostrava.
We asked who authorized this and on what basis. Those who authorised it were unable to support their decision with arguments. We urged that these applications be kept out of the children’s environment because we did not know what the impact would be. Titanium dioxide is very stable and does not decompose, so we can assume it might have negative effects if it enters the body. We were challenged to prove the negative effects, which was difficult Our effort was to prevent the use in environments with children, which was ultimately successful, and the application was excluded from the city’s strategies. A recommendation was sent out to not use the sprays in environments with children. There is a difference in whether it is applied in a nursing home or a daycare, because the prospect of a child continuing to live with nanoparticles in their body is much longer than a nursing home client. We have also been challenged to prove that it can have an effect on the development of cancer, which is an extreme case. We do not have to discuss such extreme cases, but we can discuss the possible influence on the development of allergic reactions, which we also know nothing about. Who is going to prove it then, when such a reaction occurs in a child in primary or secondary school, when the nanoparticles suddenly trigger something after years of being deposited in the body?
The grounds for these sprays increased especially during the COVID pandemic. What is your opinion on that?
Jana: The use of nanotechnology in the fight against COVID-19 has its justification, as we have seen with nanofibrous fabric drapes or vaccines containing lipid nanoparticles. These applications make sense. However, the use of titanium dioxide nanoparticle sprays on tables and sanitary facilities as a prevention of respiratory disease seems less logical. Respiratory illnesses are usually transmitted via the droplet route, i.e. by inhalation of air, not by contact with contaminated surfaces. A study published in the Nature journal reports that the likelihood of getting infected from contact with a contaminated surface is only about five percent. In contrast, inhaling infectious particles, whether viruses or bacteria, is much more likely. From this perspective, it seems that the rational justification for using these sprays to combat respiratory disease is lacking, and the motivation behind their use may be different from addressing respiratory disease.
“Certainly there are applications of nanomaterials that are very beneficial, for example in the field of pharmaceutics. However, it is important to approach the development and use of nanomaterials with caution and consideration, rather than letting the market drive the field entirely.”
I have read that respirators and hoods release micro and nanoparticles when worn and when degraded in the environment . Given the amount of these disposables used and found in the seas and rivers, it is assumed that vast amounts of nanoparticles are released. How do nanoparticles affect the environment, where can they cause a problem?
Jana: The release of nanoparticles from facemasks is probably more a matter of nanofiber fragments than the nanoparticles themselves, unless it is nanofibers with nanoparticles deposited on the surface. It is important to distinguish between the two types. Unlike the titanium dioxide nanoparticles we discussed earlier, the materials used in the facemasks are usually organic in origin and are degradable. This means that they can degrade over time, unlike metal compounds, which are non-degradable. Thus, in the case of facemasks, respirators and nanofibers, this is a different scenario compared to titanium dioxide nanoparticles, mainly because of their chemical composition.
During the COVID-19 pandemic, huge quantities of disposable protective equipment were produced. Our faculty is looking at methods to recycle some of these materials, such as protective shields and other items, and put them back into circulation to reduce the amount of disposable waste. The aim is to prevent them from being incinerated or dumped in landfills. Although the problem of single-use waste is obvious, we do not foresee large quantities of nanoparticles being released from these materials. Nanofiber fragments may be emitted, but these should be able to degrade over time.
So is there any need to worry, is it even possible to control the emerging nanoparticles? Some nanoparticles are even beneficial, are they not?
Jana: Concerns about nanoparticles are well-founded, and that could be a topic for an entire semester of lectures. When we look at the different scenarios and processes in which nanoparticles are released into the environment and we are exposed to them, we find that there are nanoparticles, or ultrafine particles, that have been part of our environment since time began. Examples are the soot that is produced by forest fires, volcanic activity or any combustion process. Our organism is somehow prepared to fight them and has certain defence mechanisms. However, there are also nanoparticles that are completely new, arising in connection with the development of new chemicals and compounds for various applications. For example, silver-based nanoparticles have not always been part of our environment. If we were to start using socks and textiles with nanosilver on a massive scale, which are gradually released into waste waters, it could trigger the need for new technologies for wastewater treatment, as conventional treatment plants may not be able to deal with it effectively. This is one of the many aspects to be considered.
Of course, there are applications of nanomaterials that are very beneficial, for example in medicine. However, it is important to approach the development and use of nanomaterials with caution and consideration, rather than letting the market drive this area entirely.
An example of this can be the use of cars. Although car accidents are common, people still use cars, but with awareness of rules and safety precautions such as wearing seat belts and obeying traffic laws. For nanomaterials, however, there is a lack of clearly defined rules and recommendations for their safe use.
There is therefore a need for intervention by government institutions such as the Ministry of Health or the Ministry of the Environment and other relevant ministries to establish clear rules and recommendations for the safe use of nanomaterials. Such regulation is necessary to minimise the risks associated with the use of nanotechnologies.
But where exactly can nanoparticles help? I have read it can help a lot that in medicine and healthcare in general, what do you think about that?
Jana: Where can nanoparticles help? Certainly in healthcare, there is no doubt. There are also so-called environmental nanotechnologies, in which various nanocatalysts and nanoabsorbents are used to clean the air, water and to perform various decontaminations. These applications definitely make sense. However, there is still the risk that some applications may result in the uncontrolled release of these nanoparticles into the environment. So again we come to the matter of the conditions under which nanoparticles are safe to handle.
Is there anything you’d like to say in conclusion?
Jana: In conclusion, perhaps I would like to encourage not to judge nanoparticles and nanomaterials from only one point of view. There are two sides to this coin. We once talked about the risks, which can have negative effects and do not look very promising. However, there is another side to this coin, and that is the benefits. We were able to address the situation during the COVID pandemic with the use of nanomaterials, which shows that, if handled carefully, they can have a significant positive impact. Nanomaterials can indeed help mankind, but we must not use them recklessly, especially not with children, because we could be in for unpleasant surprises concerning their effects.
Thank you 🙂