Nanotechnology and nanomaterials use tiny particles of the nanometre (millionth of a millimetre) size and have immense potential to improve our quality of life. However, as with any new technology or development, there are potential drawbacks. A report by GreenFacts (1).
L’One of the challenges posed by nanomaterials is to determine the differences between their biological, chemical and physical properties and those of traditional materials and how these differences impact on possible adverse effects. In concrete terms, new scientific methods need to be developed, as current methods may not be able to test nanomaterials.
Do we currently have the necessary tools to assess the potential risks of nanomaterials?
New nanomaterials are constantly being developed for a multitude of products. At the same time, our scientific knowledge and skills to explain and describe the observed properties of nanomaterials are improving, but remain limited. More importantly, our knowledge of the potential harmful effects of nanomaterials is progressing more slowly than technological developments.
Scientific research is progressing, but has not yet succeeded in establishing general descriptive models; more concrete data and knowledge on mechanisms are needed to support this process.
Can nanomaterials be harmful and do they present a risk?
In order to determine whether nanomaterials can be harmful - whether they present a danger - it is essential and important to observe that nanomaterials and nanoparticles are in the order of size of our machines used in biology. Therefore, nanomaterials are a class of components that is toxicologically "new" because they can interact with biological systems in a way that we know only partially today. However, size is not the only parameter responsible for a potential toxic effect of a given nanoparticle.
Inhaling certain nano-sized particles may cause local inflammation of the lungs, allergic reactions or adverse effects on genes. Specific types of nano-fibres can cause asbestos-like reactions, including chronic inflammation. Other concerns relate to internal exposure, as some particles can enter the bloodstream and accumulate in organs such as the liver and spleen. Nanoparticles can enter cells, which in turn can lead to direct and indirect genotoxic effects.
In addition, new generations of complex and sophisticated nanomaterials are specifically designed for bio-interactions or have a self-assembling nature. These nanomaterials can have complex dynamic behaviours, which fundamentally complicates the scientific research process. This new category of nanoparticles includes nano-capsules that have been designed for use in food products and are already used for medical purposes.
For the risk assessment of exposure to nanoparticles under real-world conditions, the generally used methods also need to be adapted due to the special properties of some nanomaterials. This remains a considerable and time-consuming effort. For workplace exposure, pragmatic approaches have been developed to help assess and subsequently control exposure to nanoparticles.
What are the environmental risks of nanoparticles?
The diversity of data on impact and on nanomaterials prevents conclusions on the environmental risks of certain nanomaterials.
Most of the available information concerns the aquatic environment and almost no information exists on the hazards of nanoparticles in soils and sediments. Increasing attention is being paid to the potential adverse effects of transformation products that are formed after introducing a nanomaterial into the environment.
Models that describe the release of nanoparticles, their distribution in the environment and the exposure of living organisms to them remain scarce, as do the data to validate these models. There is a need to advance the development of analytical tools and methods to identify and measure nano-characteristics in complex media to obtain data on the presence of and exposure to nanomaterials.
An assessment of the risks to the environment of metallic zinc particles has pointed out that the gap between effect levels and exposure levels is relatively large, so that no risk to organisms in Community waters is yet anticipated. However, a similar assessment for nanosilver particles does not exclude the possibility of adverse effects on the environment.
What are the main gaps in knowledge?
Progress must be made in the following four areas:
Firstly, we seriously need data - i.e. specific data on nanomaterials and nanoparticles, but also information on the use of nanomaterials/particles in products and their release from these products.
Secondly, we must improve our scientific knowledge of nano-toxicological behaviour in order to progress along the path of generalisation and abstraction.
Thirdly, we need to look not only at existing simple nanomaterials, but also to monitor and evaluate the development of new generations of nanomaterials.
Fourth, we need to look at risk governance aspects and how to manage the difference in pace between nanomaterial innovations and our scientific and regulatory capacity to assess uncertainties and risks, and how to deal with these potential risks and uncertainties.
Government, society at large, the scientific community and business need to work together to find ways to manage the innovative and fundamentally new development of materials and risks. This would enhance data availability and mutual knowledge.
Overall, the European Commission concluded that the current European legislative framework covers, to a large extent, the potential risks related to nanomaterials. However, there may be a need to revise the current legislation in the light of remaining gaps and new information, in particular with regard to threshold values.
(Source : www.rivm.nl/en)
TO BE FOLLOWED : Day NanoLille on March 10, 2017: "The production, activities and uses of nanos: the conditions of trust". - This discussion day is aimed at all actors involved in nanotechnologies or interested in their development and their social and economic implications. It aims to provide a particularly well-informed overview of the available knowledge and gaps in each of the fields concerned by the development of nanomaterials and nanotechnologies, and to promote collective reflection capable of setting out the prerequisites for the sustainable and responsible development of these new technologies.
References:
Assessing health and environmental risks of nanoparticles: Current state of affairs in policy, science and areas of application
Assessing health & environmental risks of nanoparticles - An overview
(1) The GreeenFacts initiative is a non-profit project with an independent scientific committee and a policy of impartiality. Their mission is to make complex scientific reports on health and the environment accessible to non-specialists. GreenFacts is an editorial partner of UP'magazine.
