What are the main properties of nanomaterials

Health and environmental risks of nanoparticles and nanomaterials

introduction

Nanotechnologies and materials use tiny nanometer-sized particles (millionths of a millimeter) that can go a long way in improving our quality of life. However, like any new technology or development, they also have potential disadvantages.

One challenge for nanomaterials is to determine to what extent their physical, chemical and biological properties differ from those of conventional materials and how this influences possible harmful effects. In practice, new scientific methods are needed because current methods may not prove to be adapted for testing nanomaterials.

Do we now have the tools to assess the potential risks of nanomaterials?

New nanomaterials are constantly being developed for a range of products. However, our scientific understanding and our ability to explain and describe the observed properties of nanomaterials are growing, but are still relatively limited. More importantly, our knowledge of the possible harmful effects of nanomaterials is making slower progress than technological developments.

Scientific knowledge is increasing, but is not yet able to provide general descriptive models; more practical data and an understanding of the mechanisms are needed to facilitate this process.

Can nanomaterials have a harmful effect and do they pose a risk?

When assessing whether nanomaterials can have a harmful effect, whether they pose a risk1 a fundamental, important consideration is that the size of the nanomaterials and nanoparticles corresponds to that of our biological machinery. Therefore, nanomaterials are a class of substances that are toxicologically “new” because they are in one with biological systems.

Interact in ways that we currently only partially understand. However, the size is not the only decisive factor for a possible toxic effect of a particular nanoparticle

Inhaling certain nanoparticles can lead to local pneumonia, allergic reactions or harmful effects on the genes. Some specific types of nanofibers can cause reactions similar to asbestos, including chronic inflammation. Particles that enter the bloodstream and could build up in organs such as the liver and spleen are an additional concern. Nano can penetrate cells and thus directly or indirectly affect the genetic material of the cell.

New generations of complex nanomaterials are now being developed specifically for biological interactions or with self-organizing properties. These nanomaterials can behave in complex, dynamic ways, which fundamentally complicates the process of scientific evaluation. This new class of nanoparticles includes in particular nano-encapsulations, which were developed for use in food and feed and are already used for medical purposes.

In order to assess the risk of exposure to nanomaterials under real conditions, the methods commonly used must also be adapted due to the specific properties of some nanomaterials. This is time consuming and still requires considerable effort. For exposure to the workplace, pragmatic approaches have been developed in order to facilitate the assessment and subsequent monitoring of exposure to nanoparticles.

What are the environmental risks of nanoparticles?

Due to the variety of impact data and nanomaterials, it is difficult to draw conclusions about the environmental risks of certain nanomaterials.

Most of the information available relates to bodies of water and there is largely a lack of information on the hazards of nanoparticles in soils and sediments. If a nanomaterial gets into the environment, it can be transformed. Increasing attention is paid to possible harmful effects of these conversion products.

There is still a lack of description models for the release of nanoparticles, their distribution in the environment and how living things are exposed to them. Model-supporting data are also still rare. A further development of the analysis tools and the methods for the determination and measurement of the properties of nanoparticles in complex environmental conditions are required in order to better understand their distribution and the burden on living beings in the environment.

An environmental impact assessment for zinc metal particles has shown that the scope between the levels of impact and exposure is relatively large, so that no risk to living organisms in EU waters is currently to be expected. But a similar assessment for nanosilver does not rule out the possibility of damaging effects on the environment.

What are the most important knowledge gaps?

Progress needs to be made in four main areas:

First we need Data - i.e. specific data on nanomaterials and nanoparticles as well as information on their use in and their release from products.

Secondly we need ours scientific understanding improve nano-toxicological behavior to enable the move towards generalization and abstraction.

Third we not only have to evaluate existing nanomaterials, but also monitor and assess new and emerging generations of nanomaterials.

Fourth we need to consider aspects of risk management, such as dealing with the tempo difference between nanomaterial innovations and our scientific and legal capacity to assess the uncertainties and risks, and ways to deal with these potential risks and uncertainties.

Government, society in general, scientists and business circles must work together to find ways to deal with fundamentally new and innovative developments in both materials and risks. This would create a solid foundation for more data availability and mutual understanding.

In general, the European Commission concluded that the EU legal framework largely covers potential risks related to nanomaterials. Nonetheless, current legislation and limit values ​​may need to be adjusted in the future in view of existing gaps and new knowledge, ...

1 To explain the main difference between a “hazard” and a “risk” in this context, you can watch the short GreenFacts video on this topic: www.youtube.com/watch?v=PZmNZi8bon8