EUROPEAN NANOETHICS WORKSHOP, UNIVERSITY OF AARHUS, NOV 07
‘Toxicological and Environmental Aspects of Nanotechnology’
Paper given by David Fieldsend, Manager, CARE for Europe
NANOTECHNOLOGY: GREAT POTENTIAL FOR GOOD & ILL?
1. Nanotech: 4th industrial revolution?
Great Expectations
1.1 Some $8.6bn1 annually of public research funding worldwide ($1bn each from the
US and Japan) is being invested in nanotechnology. Many “Fortune 500” companies have
now joined the race, alongside SMEs and research institutes to patent new
nanotechnology products and carve out for themselves new market segments based on
these. The market for nanotechnology products is estimated at $700bn by 2008 and $1
trillion by 20152. This is only happening because of the discovery that nanoparticles
(defined as objects less than 100 nanometres across, that is 100 thousand millionths of a
metre, down to atomic scale – approx 0.2 nm) often behave in a completely different way
to „larger‟ or more „normal‟ particles of the same substance.
Great Performance
1.2 This is because particles at nano scale have a relatively larger surface area in
proportion to mass than the same materials at „normal‟ scale – this can make them more
chemically reactive (including those that are normally inert, eg. gold - classically inert
but which becomes a useful catalyst at nanoscale) - insoluble substances can become
soluble, electric insulators can become conductors, the opaque transparent, and so on.
Below 50 nm the laws of classical physics cease to apply and the less easily predictable
world of quantum physics takes over. As physics Nobel laureate Horst Stoermer said in
19983 ‘nanotechnology has given us the tools….to play with the ultimate toy box of
nature – atoms and molecules. Everything is made from it…. The possibilities to create
new things appear limitless.’ One feature of this „playing‟ is the potential for products to
„self-assemble‟ from the right admixture of base components in a solution or gaseous
form.
1.3 Nanotechnologies also enable other technologies and connect diverse disciplines
such as physics, chemistry, genetics, ICTs and cognitive sciences thus offering the
foundation for the NBIC „nano-bio-info-cogno‟ convergence. Forecasters highlight likely
benefit for, inter alia4:
materials sciences
cosmetics
house-cleaning products
paints, varnishes & other coatings
chemistry
ICT
Biomedical applications
Environmental remediation tehcnology
Energy capture & storage technology
Agriculture
Food
Military technology
Textiles, surface finishings & lubricating agents
1.4 Indeed one of the most distinguished researchers in this field, the late Richard
Smalley, Nobel Laureate of Rice University, Texas considered that he had good
justification to state that ‘the impact of nanotechnology on health, wealth, and the
standard of living for people will be at least equivalent to the combined influences of
microelectronics, medical imaging, computer-aided engineering, and man-made
polymers’5. In short, a fourth industrial revolution.
2. Reaching the parts that others cannot
2.1 The great interest in nano is precisely because materials at this scale (atomic,
molecular and macromolecular) offer significantly different properties from those at a
larger „normal‟ scale. Nanomaterials can be constructed either from the „top down‟ by
producing very small structures from larger pieces of material (for example by etching to
create circuits on the surface of a silicon microchip) or by „bottom up‟ technology
constructing the product atom by atom or molecule by molecule.- this can be either
through self-assembly in which the component parts arrange themselves due to their
natural properties (such as crystals grown for the semiconductor industry or the chemical
synthesis of larger molecules ) or by positioning each atom or molecule individually
using high precision tools. (too laborious for industrial applications). Nanoparticles can
come in liquid, gas or solid form, usually applied as a paste, gel or coating.
In the Body
2.2 In medicine this means that is now possible for medications to reach the parts that
previous delivery methods have never been able to reach. In cancer treatments and
neurological disorders tiny targeted doses can be delivered where previously the whole
body, or large parts of it, had to be medicated in order for a small part of the dose to reach
its intended target, with inevitable unwished for side effects. Indeed such is the potential
that Andrew Von Eschenbach, head of the US National Cancer Instit, has been moved to
state that thanks to advances in nanomedicine we shall ‘eliminate suffering and death
due to cancer by 2015’6.
In the Chip
2.3 In ICT an exponential growth in the memory capacity of microchips is predicted.
The current manufacturing standard set in 2004 is 90nm, it is predicted that by 2016 this
will be reduced to just 22nm, enabling the postulates of Moore‟s Law7 to be completely
outstripped.
In the Environment
2.4 Environmental remediation is another sphere where research, especially in North
America, has indicated a useful potential for nanoparticles. Their small size makes
possible the achievement of a surface area of 1,000 sq m from just a gramme of particles.
This active surface can enter into a chemical reaction with toxic contaminants – whether
in the soil, ground water or air – and „neutralise‟ them. In theory the same technology
ought to be applicable to industrial processes making possibly the stripping out of waste
products and rendering them harmless before they leave the premises.
In the Gadget
2.5 Consumer products such as cosmetics and ultra strong sunscreen which are totally
transparent, self-cleaning drinking utensils and larger surfaces like whole windows that
keep themselves clean are possible with nanotechnology. The conductivity of carbon
nanotubes is likely to see them exploited in producing super efficient fuel cells. Also new
forms of organic lighting (inc the next generation of flat screen TVs) and solar cells
which can be simply sprayed onto buildings or applied as a dye coating a few nm thick to
clothing will become possible.
3. Vive la difference?
Nanoparticles can only do all this because they are different
This means risk potential is different too
3.1 But it is precisely these special qualities which make nanoparticles so attractive to
industry which give rise to predictions of risk. Their more mobile behaviour than their
larger „normal‟ particulate cousins means that they have almost unrestricted access to the
human body. The possibility of absorption through the skin is still being studied, whilst
entry into the bloodstream via the lungs has been demonstrated in laboratory animals 8 9
with carbon nanotubes proving more toxic to rats than quartz particles and inducing lung
granulomas.Entry into the body via the digestive tract is also feasible. Exposure of
laboratory rats to polystyrene nanoparticles via this route resulted in a X100 increaase in
the incidence of diabetes10. Once in the bloodstream the particles appear to be able to
travel freely around the body, and even the blood-brain11 barrier presents no significant
obstacle. Lab reports show that test particles can be detected in the brain even a short
time after administration. Particles have also been demonstrated to travel to the brain via
the nasal mucous membrane. Nanoparticles already in use medically include derivatives
of iron for magnetic marking purposes. Some of these may reach and accumulate in the
brain – considering that a range of brain disorders are thought to be related to disruptions
of the iron concentration there this must be of concern. Generally the body‟s defences are
not able to effectively identify and exclude or mark for excretion particles below
200nm12.
3.2 Once inside the body the potential for damage depends on the reactive qualities of
the particle which relate to the surface coating used. Chemical damage may be caused to
the surrounding tissue through the formation of „free radicals‟. Cell walls and idoplasm
are known to be susceptible to damage by free radicals – this is the mechanism by which
excessive exposure to the sun can trigger tumour formation.
3.3 Although the UK only currently has a „very small‟ nanotechnology sector
according to Government sources13 the Health & Safety Executive has estimated that the
number of people affected by workplace exposure to nanoparticles in universities and
nano companies could be as high as 2,000, with up to 1,000,000 exposed to lesser
degrees of risk with powders and the products of welding and refining that include
nanoparticulate matter14. A correlation has also been noted between the concentration
levels of airborne nanoparticles and so-called „sick building syndrome‟15.
3.4 Their environmental mobility is also a cause for concern. Specially manufactured
coatings can prevent them clumping together or being dissolved in water or otherwise
absorbed. This means that once airborne they can theoretically drift on almost endlessly.
They do not settle on surfaces as larger particles would and are only stopped when
inhaled or some other specific physical limitation on their dissemination is encountered.
The same properties hold true on land, in earth and in water. Once in geological strata
there would be nothing to hinder their entry into the public water supply as current
filtering techniques could not detect them.
3.5 It may be that the presence and accumulation of manufactured nanoparticles in the
environment, and especially in the human body where they may concentrate in certain
organs, is not a problem. However, the paucity of research to date means that we cannot
be sure and experiments with laboratory animals exposed to nanomaterials have got as far
as demonstrating the potential for risk16 – this has included investigation of the
pulmonary toxicity of single wall carbon nanotubes in the trachea of mice and rats. This
showed unique toxic properties for the tubes different from those of incidental particles
(eg. Carbon black).
3.6 The problem is we don‟t really know. Unless and until the necessary research has
been carried out to confirm their toxicology, or otherwise, we are working in the dark.
Regulatory regime is failing to respond
3.7 However, despite the obvious difference in properties from particles of „normal‟
size there are no special regulations for the testing, handling or dissemination of nano
materials which are almost universally considered by the regulatory authorities to be no
different to ordinary particles of their base materials (which is as true for the world
leaders in this field, the US and Japan, as it is for Europe.
3.8 It may be that these new artificially manufactured nanoparticles are totally benign
in their interactions with the human body and our environment and should be no cause
for concern for those responsible for the protecting the health of workers involved in their
manufacture, consumers making the use of these products and our environment in
relation to the effect of release of these particles both during normal product use and in
waste disposal at the end of the product‟s lifecycle. The truth is that at this stage of the
game we just do not know.
3.9 This would be less worrying if we were purely talking of possible future
developments for which we have the luxury of time to plan. In fact nanotech is no longer
future, it is very much present.
4. Not future tech, very much present tech
356 products already on the market
4.1 These revolutionary new products and processes are not just future hype or future
realistic forecast, they are happening already. At the end of 200617 356 products or
product lines (up 70% from the previous year) were on the market globally, ranging from
the latest 64FX processor to nanotea (enriched with selenium nanoparticles). These
products include scratchproof eyeglasses, crack-resistant paints, self-cleaning windows
and ceramic coatings for solar cells. Titanium dioxide nanoparticles are used in sun
cream; carbon nanotubes strengthen tennis rackets and fishing rods; gold, aluminium and
palladium nanoparticles are catalysts in fuel cells – as well as a cerium oxide based
catalyst which improves the efficiency of diesel engines and reduces CO2 emissions -
and paramagnetic nanospheres are used as drug delivery systems. Iron oxide
nanoparticles are also used to „mark‟ individual cells used in transplant trials so that their
progress can be detected by MRI scanning and nanotechnologically enhanced products
are also used in tooth and bone implants, disinfectant, adhesive plasters and bandages.
4.2 This gives us a concerning paradox. A wide range of products is out there,
inevitably escaping in some sort of quantities to the environment and hence able to access
people‟s bodies – but we do not yet have a complete picture of the full implications for
either human or environmental health of manufactured nanoparticulate substances.
5. Proportionate response? Paradoxical situation evokes varied reactions
Green Lobby
5.1 The response from some quarters (eg. Greenpeace & the Soil Association) is to
plead the precautionary principle and call for a moratorium on bringing to the market all
products making use of nanoparticles until research has been carried out which can
demonstrate the distribution routes and full potential impact on human health and the
environment of their release.
Insurance Industry
5.2 This uncertainty has also led some of those responsible for calculating the risk
involved for insurance purposes18 to search their files for precedents in recent history for
the introduction of novel technology involving microscopic particles and being somewhat
disturbed by what they have found – namely the worrying case of asbestos. This product
was very widely used – in fact specified as compulsory by the regulatory authorities
because of its fire retardant qualities – in the construction industry for many years before
the deleterious effects on the health of workers installing it - and later DIY devotees
coming across it in their homes and releasing the deadly particles with their power tools –
became apparent. More research (or more properly more publication of research) before
the product was pressed into widespread use should have uncovered the safety hazards
involved through the adverse reaction between asbestos particles and the lining of the
human lung. As the general rule is that the smaller the particle, the greater the reaction
that is triggered when contact is made with the lining of the lung a healthy scepticism in
relation to the safety implications of the nanotechnology revolution is understandable.
Science Establishment
5.3 The Swiss Re report concentrated on free nanoparticles released in products (for
instance cosmetics and sprays) where this was an expected component of use, or during
the manufacturing and end of life disposal stages. In a later Report19 the UK Royal
Society (the national academy of science for the UK) and the Royal Academy of
Engineering emphasised that in most products then in use particles were actually fixed or
embedded in the product during the manufacturing process (RS, p3) and so the risks
posed by free nanoparticles for human health and the environment were unlikely to be a
factor during the normal use of these products, but only at the beginning and end of their
life. They considered the calls for a moratorium but stated that (RS83) hey did not think
this „necessary on a precautionary basis. We have recommended measures that will
minimise exposure while the uncertainties about the hazards posed by nanoparticles and
nanotubes are being addressed’.
„Plug the gaps‟
5.4 What both the Swiss Re and Royal Society reports have in common is their
advocacy that these nanoparticles should have their own specific regulatory regime and
be separated from the treatment of larger particles of the same substance. The
introduction of products making first time use of any particular nanoparticles would
therefore be subject to novel product procedures and the necessary research into potential
safety hazards required to be undertaken and published. This would enable both
reassurance of the consumer and allow accurate risk assessment on the part of a
prospective insurer. This change is specifically advocated both the European
Commission‟s REACH (Registration, Evaluation, Authorisation and Restriction of
Chemicals) process for the evaluation of chemical products and the national regulatory
regime in the UK. The Royal Society report also called for an independent review to be
undertaken „in two and five years’ time’ on progress in taking action on its
recommendations.
5.5 The European Commission‟s scientific committee on emerging and newly
identified health risks (SCENIHR) makes much the same demands in its report of 10th
March 200620 on the appropriateness of existing methodologies to assess the potential
risks associated with engineered and adventitious products of nanotechnologies calling
(p55) for nanoparticles to be assigned a different CAS (Chemicals Abstract Service) code
from larger particles of the same chemical substance and review of the REACH tonnage
thresholds as inappropriate in relation to nanoparticles. Their report also calls for new
workplace standards for the handling of nanoparticles pointing out that current regimes I
relation to dusts are not adequate. Also exposure dose limits need to be redefined in terms
of the number of particles and/or surface area rather than purely mass.
5.6 The SCENIHR report also identifies current „knowledge gaps‟ which urgently
need to be filled before sound guidance can be given on acceptable exposure levels to
manufactured nanoparticles:-
* The characterisation of the mechanisms and kinetics of the release of
nanoparticles from a very wide range of production processes, formulations and uses of
the products of nanotechnology.
* The actual range of exposure levels, both to man and to the environment,
experienced during use of nanoparticle based products.
* The extent to which it is possible to extrapolate from the toxicology of non-nano
sized fibres, particles and other physical forms of the same substance to the toxicology of
nanosized materials.
* Toxicokinetic data following exposure at various portals of entry, so that target
organs can be identified and doses for hazard assessment determined. This includes dose
response data for the target organs, and knowledge of the subcellular location of
nanoparticles and their mechanistic effects at the cellular level.
* Information on the health of workers involved in the manufacture and processing
of nanoparticles.
* The fate, distribution and persistence (including bioaccumulation) of
nanoparticles in the environment.
* The effects of nanoparticles on various environmental species, in each of the
environmental compartments and representative of different trophic levels and exposure
routes.
6. Govt & EC – Policy Response
UK Government
6.1 The UK Government published its response to the Royal Society report in
February 200521. This stated that it would review regulations „to reflect the possibility
that nanoparticulate material may have greater toxicity than material in the larger size
range (para 22)’. It also stated that manufactured free nanoparticles should ‘undergo a
thorough safety assessment by the relevant scientific body before they are used in
consumer products’(para 24). Because of the high (for nanomaterials in any case)
threshold for applicability of the REACH evaluation process (one tonne per annum of
anticipated production) the British Government did not accept the recommendation of a
separate category within REACH for nanoparticles but instead considered that new
sector specific regulations – separate from REACH – might be required (para 25).
6.2 The UK Government response also accepted the need to minimise workplace
exposure until the possible risks posed by nanomaterials were better understood. It also
said that it was „strongly committed to filling gaps in knowledge through an immediate
programme of research aimed at reducing the uncertainties relating to toxicity and
exposure pathways for nanoparticulates, as well as developing instrumentation to
monitor these in the workplace and the environment’ and stated that it „would expect
substantial progress to have been made when the CST (Council for Science and
Technology) reviews progress after two years’.(para 15) The response also referred to
British participation in three European studies – investigating current exposure levels and
control measures in university labs and the behaviour of aerosol particles (both under the
auspices of Nanosh (Nanoparticle Occupational Safety and Health) and the Nanosafe2
project looking at measurement, health effects, procedures for safe handling and societal
issues.
6.3 A voluntary reporting scheme for industry (based in the Department for the
Environment, Food and Rural Affairs – DEFRA) to provide government with information
relevant to the understanding of potential risks in relation to free engineered nanoparticles
was also referred to, along with an agreement reached with industry not to go ahead with
the use of nanoparticles for environmental remediation until there had been further study
of the potential side effects.
European Commission
6.4 In May 2004 the Commission adopted a „Communication Towards a European
Strategy for Nanotechnology22. This called for „public health, occupational health and
safety, environmental and consumer risks’ to be addressed „at the earliest possible stage’.
In June 2005 this was followed up by „Nanoscience and nanotechnologies: An action
plan for Europe 2005-200923. In it the Commission committed itself, inter alia, to
doubling the budget for nano R & D in the new (7th) framework programme; ‘boosting
support for collaborative R & D into the potential impact on human health and the
environment‟ and called upon Member States to ‘take nanoparticles into account in the
enforcement of the new substances notification scheme’ and ‘support the adoption of
universally recognised CAS registry numbers and Material Safety Data Sheets for
nanomaterials’.
6.5 However, the European regulatory regime does not yet, as a general rule, consider
nanoparticles differently from „normal‟ particles of the same substance with the specific
exception of certain specific types of nanomaterials such as fullerenes (a generic term
which should include carbon nanotubes and buckyballs) which are classed as „novel
materials‟24. The one tonne general annual threshold also remains.
7. Govt & EC – Practical Response
UK Government
7.1 Earlier this year (March 2007) the requested two year review of action taken to
implement the UK Government‟s response was also published25. This stated that although
a number of individual departmental reviews had been carried out during 2006 and gaps
in regulatory provision identified, followed by an overarching review of regulatory gaps
published by the Department of Trade and Industry (DTI) in December 2006 26 no
regulatory changes had yet been introduced. The review notes that this means that „if a
nanomaterial is considered to be non-toxic and non-harmful in its bulk form it may not be
required to undergo a sufficiently rigorous safety assessment before being included in a
consumer product’.
7.2 The review also notes that despite the strong public support from industry for the
Voluntary Reporting Scheme only three organisations to date had submitted any data
(para 92). It also expresses concerns that the data supplied could be compromised by
negative results being withheld.
7.3 But the review is most scathing (‘CST is extremely disappointed by Government’s
progress’) (para 159) over the UK Government‟s pledge to give priority to research into
possible toxicology effects of free nanoparticles. There had been a £10M spend on
nanometrology to date, with only a further £3M27 to cover all other aspects of
dissemination and toxicology research. This did not compare favourably with the £40M
annually awarded for research into the development of new nanoproducts and £90M over
six years for their commercialisation. (para X). As far as nano safety was concerned „the
amount of activity in many areas of research has been unsatisfactory and with little
tangible advance in knowledge since February 2005.’ – The potential health and
environmental effects of many nanomaterials are still not well understood, nor has
instrumentation suitable to routinely monitor workplace exposure to free manufactured
nanomaterials been developed.’ It is recommended that at least £5-6M annually should
be devoted to research on toxicology, health and environmental effects of nanomaterials.
7.4 Three priorities were also identified for this research spending (out of 19 areas
identified as needing research by the NRCG)28 :
Urgently formulating short-term toxicity protocols, focusing on the types of
nanomaterials – including metals, metal oxides and carbon nanotubes –
currently on the market and being used by industry.
A longer term need for substantive research into the toxicology, health and
environmental impacts and long term environmental fate of nanomaterials.
Development of methodologies for life cycle assessment involving
nanomaterials and the carrying out of life cycle assessments themselves
would also be valuable, though this is of lower priority than the above.
European Commission
7.5 At European level the review notes that a dossier on the specific issue of
microfine zinc oxide (now extensively used in US cosmetics) was finally submitted to the
Scientific Committee on Cosmetic and Non-Food Products (SCCNFP) in February this
year – despite the Commission having drawn Member States‟ attention to the need for it
back in September 2005. However titanium dioxide nanoparticles (SR33) – which have
been observed to cause lung inflammation and epithelial damage in laboratory rats29
continue to be treated on the same basis as „normal‟ titanium dioxide powder and the
Material Data Safety Sheet for it continues to recommend that a dust respirator be worn,
even though this is totally ineffective against nanoparticles30.
7.6 When the Commission‟s Action Plan was debated in the European Parliament in
2006 various amendments, which we supported, were tabled by the Green Party to seek
to give a higher priority to safety research funding and calling for „manufactured
nanoparticles to be labelled, classified and tested for safety as if they were new
substances’. Unfortunately they were not adopted.
Necessary Delay? or „buying time for commercial advantage?
7.7 The introduction to the European Commission‟s 2005 Action Plan refers in
glowing terms to the commercial potential on nanotech „products ..are already in use and
analysts expect markets to grow by hundreds of billions of euros during this decade.
Europe must avoid a repeat of the European ‘paradox’ witnessed for other technologies
and transform its world class R & D …into useful wealth-generating products’.
Has this fuelled a reluctance to act in precautionary ways that might be interpreted as
slowing down the pace of development on this side of the Atlantic and giving a head start
to our US competitors?
8. Where do we go from here?
References
1
Lux Research, http://www.nanalyze.com/articles/foresight_oct_04/page3.aspx
2
The Scientific Committee on Emerging and Newly Identified Health Risks report on
“The appropriateness of existing methodologies to assess the potential risks associated
with engineered and adventitious products of nanotechnologies”, page 5
3
“nanotechnology: Shaping the World Atom by Atom”, www.nano.gov
4
The Scientific Committee on Emerging and Newly Identified Health Risks report on
“The appropriateness of existing methodologies to assess the potential risks associated
with engineered and adventitious products of nanotechnologies”, page 5
5
R Smalley
6
New Yorker March 13, 2006, 69
7
Martin Patriquin, “Small Matter Provokes a Major Debate”, Toronto Globe and Mail
(19 November 2003)
8
“Nanotechnology: Small matter, many unknowns”, Swiss Re 2004, p17
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17
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18
“Nanotechnology: Small matter, many unknowns”, Swiss Re 2004
19
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20
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21
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22
European Commission, COM(2004) 338
23
European Commission COM(2005) 243
24
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25
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26
http://www.dti.gov.uk/science/science-in-
govt/st_policy_issues/nanotechnology/page20218.html
27
UK Council for Science and Technology, “Nanosciences and Nanotechnologies: A
Review of Government‟s Progress on its Policy Commitments”, March 2007, para 40.
28
“Characterising the potential risks posed by engineered nanoparticles: UK Government
research – a progress report, Nanotechnology Research Co-ordination Group, October
2006.
29
Renwick LC, Brown D, Clouter A and Donaldson K. Increased inflammation and
altered macrophage chemotactic response caused by two ultrafine particle types. Occup
Environ Med 2004, 61, 442-446.
30
“Nanotechnology: Small matter, many unknowns”, Swiss Re 2004, p33