The instigators of these new nanotechnologies (scientists and engineers) must navigate a delicate balance between technological advancement and social awareness. In addition to providing superior efficacy, products containing nanomaterials must be energy efficient, safe and environmentally friendly. Moreover, the introduction of our engineered nanomaterials into the natural world is an inevitability, rather than a worst-case-scenario. Therefore, above all else, they must also be reliable and perform their function in a predictable way.
The majority of nanomaterials engineered have no naturally occurring analogue, or are artificially modified to induce specific functionality. This introduces a certain degree of unpredictability, since we are presented with a range of untested materials that are (literally) unique on an atomic scale, with no historical data to guide our assumptions regarding the possible risks. Not surprisingly, the preliminary discussions on potential nano-hazards and toxicity associated with nanomaterials are maturing into an independent discipline.
Numerous (government and non-government) reports are widely available summarizing the current knowledge in this field, and highlighting areas requiring attention. Reading these reports, it is easy to see that the integrity of future nanodevices, our ability to manage the toxicological and environmental impacts when the devices are used in certain environments or are discarded, all require a detailed understanding of the stability of pure and functionalized nanomaterials under a full range of environmental conditions.
Unfortunately, scientists are producing such a wide variety of engineered nanoparticles at such a rapid pace, that the task of systematically measuring the stability of all possible compositions, sizes and shapes in different environments has already become impractically large. We can of course focus our efforts on those nanomaterials that are most prevalent or ubiquitous, or those that are perceived to be the most hazardous. However, this is simply not enough, because history has taught us that low probability events may still be catastrophic. We need to know how nanomaterials form, evolve, behave and change. The last on the list ensures that all of our knowledge pertaining to the other three remains relevant as nanomaterials move from one environment to another, or are perturbed by unexpected external stimuli.
Fortunately this is an area where theory and simulation can be used to see a path through the complexity, and tread the path that experiment cannot. Theory and simulation can control individual, physical or environmental parameters independently, while keeping all others constant. This allows for the systematic testing of structure–property (or structure–toxicity) relationships, to see which ones are responsible for undesirable instabilities. Together, via strategic collaborations between theory, simulation and experimentation, it is possible to rapidly sample this multi-dimensional parameter-space, while still focussing detailed investigations in the areas that need them most. Given the more specific knowledge we will be ready to build predictive models capable of protecting nanomaterials from the environment as much as they protect the environment (and us) from them.
It is important to point out, that investigations of this type are not merely a search for potential problems, but are a search for reassurances. The recent announcement by the Continental Western Group (CWG) that it will no longer issue insurance coverage for research and development work on carbon nanotubes until their toxicity of these materials has been determined, shows that our activities are under scrutiny by the greater society and others are keenly seeking these reassurances too. We should see this announcement as a great opportunity. It highlights that investigations of this type are not intended to play the role of watch dog, but to work in partnership with innovation activities and help to identify the best possible version of new discoveries to be pursued commercially. It is likely that the vast majority of nanomaterials that eventually reach the market will fulfil all of the requirements in terms of efficacy and safety, but assurance comes when consideration of toxicity and environmental impacts go together with innovation.
It is irresponsible for us to build an industry based on nanomaterials that is not sustainable, either economically, environmentally or socially. Ultimately the economically sound choice of attributes for any nanomaterial-based product are those that are desired by consumers (and will be purchased) and not necessarily those that provide the statistically optimal balance between cost and efficacy. The path to economically and environmentally sustainable nanotechnology is more than just a multi-disciplinary problem. It is a multi-field problem. An efficient strategy considering the needs of stakeholders and members of the public, will be as much an exercise in knowledge sharing and personal relationships as it will in scientific discovery. Using knowledge gained from inter-disciplinary scientific collaborations we can deliver the right information to those in a position to act upon it, and do so in a format that is accessible to and assessable by those outside of the scientific community.