Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles
Posted: Jun 16th, 2009
Approaches to safe nanotechnology
(Nanowerk Spotlight) New technologies are always polarizing society – some only see the inherent dangers, others only see the opportunities. Since these two groups usually are the loudest, everybody else inbetween has a hard time to get their message across and with objective information and facts. Nanotechnologies are no different. The nay-sayers call for a total moratorium everytime scientific research with concerning conclusions is published while opportunistic hypsters are only interested in selling more products or reports and ridicule even the faintest objections and concerns as uninformed panicmongering.
From a risk and safety point of view it is impossible to draw any definite conclusions as far as today's nanomaterials are concerned. Although gaining steam, nanotoxicological research is still scarce; standards are just emerging; and scientific findings can be contradicting each other because the underlying assumptions and methodologies vary. If you want to delve deeper into this issue, we have written several dozen Nanowerk Spotlights on this topic of nanotechnology risks.
One initiative that tried to shed light on this issue is a recently completed global review of completed and near completed environment, health and safety research on nanomaterials and nanotechnology. The resulting EMERGNANO report (pdf download, 1.2 MB) is a unique attempt to identify and assess worldwide progress in relation to nanotechnology risk issues.
The review doesn't provide any new data or conclusions but is offeres a fairly comprehensiv identification, stocktaking and analysis of of research carried out worldwide on nanotechnology safety, including that relating to hazard, exposure, risk assessment and regulation.
The EMERGNANO project, conducted under the umbrella of the SAFENANO initiative, identified more than 670 projects from around the world, and after careful selection assessed more than 260 unique, relevant projects completed, close to completion or in progress since 2004. The final report provides a comprehensive listing of projects, alongside detailed evaluation of their outputs. The authors caution, though, that they "were unable to identify significant output from many of the studies involved in the programme, including studies which had already been completed. We accept, in relation to this, that we have not captured all of the information available on these studies and it is quite likely that there is some information that we have not been able to identify by the various routes through which we attempted to do so."
The approach used in this review and analysis was to:
Develop a comprehensive and categorised list of potentially relevant studies, active since 2004;
Compile information about status, duration, funding, objectives, methods and output relating to these studies through dialogue with project leaders;
Based on preliminary review, allocate (map) the studies to the 19 ROs being considered;
Through a multidisciplinary panel of expert reviewers (the authors of this report), chosen to cover the range of scientific disciplines represented in this activity, carry out an appraisal of the contribution of each study in relation to 19 ROs, the extent to which the RO is likely to be met, and the gaps remaining;
Undertake a risk assessment appraisal identifying the need for control or management of risk, including an appraisal of whether there is sufficient information to invoke the precautionary principle for one or more nanomaterials;
And through a workshop and dialogue reach a consensus view about the remaining gaps and future priorities.
With regard to the research objectives, the assessment reveals some important progress made across the four main thematic areas of characterisation, exposure, toxicology and ecotoxicology spanned by the 19 ROs. This includes:
For characterisation and reference materials, identification of candidate materials and minimum characterisation specifications for development of reference nanoparticles for toxicological and other investigations is underway. Some commercial reference materials are now beginning to emerge.
For exposure assessment and control, recent research has conclusively shown that filters, such as those used in respiratory protective equipment and in air cleaning systems, are highly effective in removing nanoparticles from the air.
For toxicology, lack of mass balance toxicokinetics for any nanoparticle and the patchy nature of the published toxicokinetic data has proven a severe impediment to identifying extra-pulmonary hazards. In addition, testing to date has focussed on a very limited number of particle types and sizes, making it impossible to know whether all NP behave in the same way toxicokinetically, or whether (as seems more likely) a structure activity relationship will emerge that highlights certain sizes and surface chemistries as factors enhancing or limiting potential of any nanoparticle to translocate or be toxic;
In ecotoxicology, work to date has improved understanding of kinetics of nanoparticle uptake in invertebrate and vertebrate models, and has related this to toxicity. In addition, recent studies which focus on microbial organisms help to provide information on nanoparticle effects at both an individual organism and greater community level.
Currently, EMERGNANO represents the best available picture available of current strategic nanorisk research. As such, the review presents an excellent basis for assessing progress of these and other studies in the future.
Impressive as this study's scope is, the crucial statement by the authors is this: "After assessing study quality and completeness, we did not identify a sufficient body of evidence to make a qualitative risk assessment feasible for any category of nanomaterial." Given the speed of nanotechnology commercialization, this is scary. It should prompt regulators and other governing bodies to seriously step up their funding for relevant research.
In the meantime, the shouting match between the prophets of doom and the hypemeisters will continue...