Page 5. Section 3a, last paragraph.
The sentence on possibly including the effects of dimensionality on health and safety issues is intriguing.I would suggest that a good definition of nanotechnology, nanomaterialsand nanodevices should be independent from the possible health andenvironmental impacts, thus focusing the definition on the technologyitself. It is then much easier to explore potential health and environmental impact based on material and device properties within the generally accepted definition. There seem to be a number of loose definitions for nanotechnology floating around, but one that I'm finding useful at the moment from a health standpoint is 'technology that deals with engineered nanometer-length scale devices, structures and surface layers' This is broad enough to encompass (from the inhalation exposure standpoint) individual nanometer particles, collections (agglomerates) of nanometer particles, and nano-devices (such as biomechanical constructs) that may inadvertently enter the body.
Page 6 Section 3c, para 1.
Straying from my original aim to comment on health aspects, I assume something is missing here, but I was interested in the statement that '... Applications for the young would be most important, ...'!
Page 6 Section 3c, para 5.
Straying again, the concern that there is no strategic view on the development of nanotechnology in the UK is a recurring theme in the report. This is a vitally important point, and should be emphasized very strongly indeed. It is becoming very clear that this level of technology requires a high tech approach to evaluating health risks, including the development of new and novel risk models, and the development/adoption of cutting edge research tools and techniques. The only way that a relevant health and environmental impact framework can be formulated for nanotechnology is by the coordinated, parallel development of health and environmental impact-based research programs. This in turn will only be achieved within the context of a strategic view on the development of nanotechnology. Bottom line - you will not be able to address health and environmental impact of such a rapidly developing technology without strategic planning and coordination at the national (and international) level.
Page 7 Section 3e, first para.
Nanomaterials may be the most obvious area where health and safety issues will manifest themselves. However, consider that nanotechnology aims to exploit the unique properties of nanometer-scale devices and structures, forming products that are better at achieving specific ends than those previously available, or enabling previously unattainable goals to be attained. The questions need to be asked of these materials and devices: What will their impact be when introduced to systems outside the original design parameters, and what will be the impact of initially unforeseen activity/behaviour? Both questions are pertinent to health and safety issues, and are not restricted to nanomaterials alone.
Page 7 Section 3e, first para.
PM10 particles are NOT similar to nanoparticles, although nanoparticles make up a subset of PM10. Comparing the largest particles in the PM10 aerosol fraction – 10 micrometers - with nanometer-diameter particles up to 5 orders of magnitude smaller is clearly inappropriate. We still know very little indeed about the toxicity of particles in the PM10 range. Nanoparticles associated with nanotechnology will have unique physicochemical attributes previously unencountered by humans, and can not be simply lumped together with particles we feel we know something about. Carbon nanotubes are receiving increasing attention in toxicity and exposure studies. Given the material's physicochemical attributes, it can be speculated that the material will be highly toxic if sufficient exposure levels are reached, although our research has indicated that inhalation exposures at least remain low when handling the material. I am not aware that sufficient regulations exist to control the release of hazardous materials where the hazard is unknown. Airborne nanotubes is a good, and topical, example: To my knowledge, no-one has verified that emission control technologies can totally eliminate the release of airborne nanotubes - either during production, processing, or during the use of nanotube-containing materials and devices. Thus we have to assume that some level of particles are entering the workplace/environment, and people are being exposed to them. Does this constitute a health or environmental hazard? Who can tell without relevant toxicology models and data. There will be more complex materials being developed and used than carbon nanotubes in the future, that will present even greater challenges.
Page 11 Section 4d i)
This is a good start, but gives very brief coverage to dealing with hazards in order to facilitate the use of nanomaterials in products. Reducing exposure of the workforce to hazardous materials to acceptable levels will be essential - particularly in the light of current public concerns. However determining acceptable levels requires an in-depth understanding of the potential toxicity of the materials produced and the potential exposure routes. Without this knowledge, it is difficult to design commercially viable control systems. Sure, you can use clean-room or bio-safety containment conditions, but the cost will cripple industry if this level of containment is unnecessary. In the absence of clear guidelines and regulations, the most appropriate approach will be to use common sense control systems to reduce exposure levels as far as is practicable, pending further information on associated health risks.
Page 12 Section 4d vi)
The point that people have been exposed to nanoparticles since the dawn of time [my words] is a good one, and should be emphasized. The analogy with asbestos is good, although remember that it took much too long for the workforce and general population to be protected adequately, leading to a lot of unnecessary deaths. The statement that the toxicity of nanoparticles will depend on particle size, concentration and surface area is not accurate, and should be modified. For insoluble particles, we know that particle size, shape and surface area are important. However surface activity must also play a key role. Therefore it essential to know the surface chemistry and biology of the particles. You can not afford to underplay the importance of surface and bulk physicochemical properties in nanoparticles - these are what drive the desired unique properties of engineered nanoparticles, and by inference what will also drive the undesired properties!
Page 16 Section 5d
Regulator issues - regulations impacting on exposure and emission monitoring and control in fabrication and processing industries may also play a role here.
Page 18 Section 6.
I can't see any coverage of health and environmental impact in this section. However surely the fusing of mechanical and biological technologies will lead to materials and devices with unique properties that will have the potential to interact with biological environments in unpredictable ways. This is one of the areas where I think nanotechnology has the potential to lead to a major technological jump, and also the area where the health and environmental impact is most unpredictable (in my opinion). Possibly more than in any other area of nanotechnology, the questions need to be asked: What will the impact of materials and devices be when introduced to systems outside the original design parameters, and what will be the impact of initially unforeseen activity/behaviour?
Page 22 Section 7b para 3.
The point that the potential impact of nanotubes is reduced when held in a matrix is well made. However, attention must be placed on their release from materials during use and secondary processing (compare to the release of asbestos fibers during asbestos abatement).
Page 23 1st para.
A number of studies into nanotube toxicity are at various stages of planning or completion in the US.
General notes on section 7 of report
This section of the report is somewhat short, and focused on the physical aspects of nanoparticles. I think though that as nanotechnology continues to develop at an increasing pace, we need to avoid getting caught up in a narrow view of what may or may not be important from health impact standpoint. The development and use of unique materials and devices will present unique challenges to minimizing adverse health impacts. The only way that we can begin to approach the challenge is to develop a coordinated framework within which emerging health and environmental concerns can be addressed, and to build in health and environmental risk components to research and development programs. This will require national and international coordination.
As a final comment, emerging nanotechnologies have the potential to impact on society in a positive way, and it would be unfortunate if the positive impact was diluted or thwarted through ignorance arising from insufficient attention being paid to quantifying the true nature of adverse health and environmental impacts.
Hope these are of some use. Looking forward to seeing the final report.
Dr Andrew Maynard
Senior Service Fellow
National Institute for Occupational Safety and Health
Robert A Taft Laboratory