Various applications of nanomaterials are being developed for the benefit of society and the environment. For example, nanomaterials are being developed for reducing the emissions of greenhouse gases and for cleaning up polluted soils. However, the use of nanomaterials also results in the emission of nanoparticles into the air, water, and soil. So what then is the fate of these particles once they get into the environment? Do they result in risks for humans, animals, and plants? The rapid advance of nanotechnology requires answers to these questions.

Research on environmental risks

Research on the potential risks posed by nanoparticles for ecosystems is in full swing. We are now approaching the point where nano-specific adjustments of laws and regulations on substances and materials can be implemented. RIVMNational Institute for Public Health and the Environment is closely monitoring developments in the field of environmental research and is also adding its own knowledge by performing research on:

  • The processes determining the behaviour of nanoparticles in the environment;
  • The impacts of nanoparticles on ecosystems;
  • Predicting the exposure levels and effects of nanomaterials in the environment;

RIVM uses this knowledge to advise and support ministries in their policymaking on nanotechnology. At the international and European level, we contribute to integrating this knowledge in OECD test guidelines and in the regulatory framework for chemical substances in REACH.

Distribution and behaviour

We know by now that the nanoparticles ending up in the environment as a result of using nanotechnology-based products often have different properties than the particles originally present in these products. Nanoparticles behave differently in the environment compared to substances to which regulations generally apply. For example, nanoparticles can agglomerate or clump together to form larger particles. Particles can also dissolve and then form different particles. As a result of these processes, the distribution of nanoparticles in the environment differs from that of traditional chemicals and substances. Agglomerated particles, for example, lead to faster sedimentation in rivers or simply fall out of the air onto the ground. All this means that the models presently being used to assess the risks associated with various substances need to be modified and updated. This also initiated the specific development of the model SimpleBox4nano to predict the distribution of nanoparticles and the exposure of organisms to nanoparticles in the environment.

Impacts on ecosystems

Organisms may be exposed to nanoparticles through water, air or soil. Often, it is unclear whether this results in negative impacts. Studies involving earthworms, plants, and aquatic organisms such as fish and algae are needed to answer such questions. A next step is to study how potential effects on individual organisms can have consequences for complex ecosystems. Research carried out in recent years has shown that the short-term effects of the majority of nanoparticles on the ecosystem are rather limited. Nevertheless, there is still concern about the long-term effects. As relevant information in this area is currently lacking, new research efforts have been initiated into the chronic effects of nanomaterials.

What are the risks?

An important question here is whether the current environmental risk assessment methods in use for chemical substances are adequate for nanoparticles. As yet, no indications exist that this is not the case. However, nano-specific adjustments to laws and regulations are still needed. Examples of such adjustments were given above and include issues such as the stability of the particles and the environmental effects of the particles and their degradation products. RIVM aims to provide insight into these issues, in part by performing research itself but primarily by closely monitoring international developments in this area.