At its 3-year mark, NanoFATE identified Five Big Questions current in ecotoxicological risk assessment for engineered nanoparticles (ENPs). Replies to these questions, identified by our focussed work packages, are the concentrate of NanoFATE methodological development and testing.
The resulting Advice Notes are useful for researchers but also for regulators. They point the way to further research, and flag issues that regulators should attend to when setting assessment guidelines and regulatory practice. The NanoFATE Advice Notes below are downloadable two-page documents containing links to the supporting NanoFATE research in deliverables and peer-reviewed papers (which are also accessible via our library).
Below the Five Big Questions are listed with associated rules-of-thumb distilled from the detailed Advice Notes. Interested readers can identify in this way the Advice Notes they wish to consult, and right-click to open the pdf notes in a new tab as available.
We continue to refine these notes as further results are analyzed - at publication time of our Newsletter 6, the Advice Notes 6, 8 & 9 are intentionally not available. We will alert our mailing list when these come online.
Q1 - What are the effects of coatings on fate, behaviour and toxicity of NPs?
NanoFATE has demonstrated an effect of coating on the behaviour and toxicity of zinc oxide (ZnO) NPs in regard to springtails.
Advice note 2 - NanoFATE has demonstrated (confirmed) a need for case-by-case consideration of coating effects on NP behaviour and toxicity.
Q2 – Are there examples of metal nanoparticles acting through a different mechanism and/or being more toxic than the ionic forms?
Advice note 3 - NPs and ions have different toxicokinetics leading to differing internal levels of metals. Ionic Ag is more toxic than AgNP based on mass calculations.
Advice note 4 - NanoFATE has demonstrated that protective genes, biochemical pathways and sequestration mechanisms are largely similar in the case of exposure to NPs or to the ionic form of the metal.
Q3 - What is a workable way of proving / analysing whether nanoparticles are present in tissues or media (cf. EU Definition)?
Advice note 5 - Given the right resources we have the methodology to find NPs inside tissues. Some of the identified particles are of an environmental rather than a manufactured origin.
Advice note 6 - Compared to human health studies, it is not as important to find NPs inside tissues in order to be able to demonstrate their risk to the environment or understand their mechanisms.
Q4 – Given that particles differ in their properties, what determines if particles can be grouped for risk assessments, and when is a case-by-case approach necessary?
Advice note 7 – NanoFATE has demonstrated that for zinc oxide (ZnO) particles, properties like coating and size do importantly differentiate the ENPs in terms of their fate and toxicity.
Advice note 8 – ENPs can be treated as "the same" if properties fall within the range seen in already investigated ENPs.
Q5 – Is the accuracy of today's risk assessment for 1st generation NPs sufficient to assess the risk that these materials may pose?
Advice note 9 - The following components are needed to improve risk assessment:
- Good data on production volumes and use patterns
- Broader selection of well-characterised test particles in sufficient amounts
- Assessment of uncertainty in scenarios and estimation of risk quotients
Advice Note 10 - For both zinc oxide and silver the risk assessment for ionic forms would most often be adequate for ENPs.