Nanotechnology: views of Scientists and Engineers
Health, safety, environmental and social issues
a) Overview
Following on from the technical sessions of the morning,
the afternoon sessions comprised of three interdisciplinary
groups which were asked to consider the following terms
of reference of the study:
- What health, safety and environmental
issues arise from developments in nanotechnology,
and what will be the benefits and risks?
- Is there a need for new regulation?
- What are the social and ethical issues
of nanotechnology?
- What other factors may influence the
development of nanotechnology?
Although a clear minority of attendees had direct health,
safety and environmental expertise, the majority of
participants felt that it was important to consider
and discuss these issues. This document represents a
summary of the discussions in all three breakout groups.
The issues raised will be followed up in subsequent
meetings and workshops that the working group is holding.
b) Health, safety and environmental
issues
The majority of participants raised nanoparticles
as a topic of discussion due to their potential (and
in some cases current) uses in the medical, cosmetic
and electronics industries. A key point was made that
although air breathing animals including humans have
been exposed to nanoparticles generated by combustion
throughout evolution, nanotechnology is now enabling
new families of small particles, such as carbon nanotubes,
which have potential applications across a wide spectrum
of industries. Possible benefits of nanoparticles highlighted
by the workshop included better targeted drugs and delivery,
highly sensitive nanosensors for the detection of diseases,
flat panel displays, sun creams, and ultra-strong, ultra-light
composite materials.
Numerous positive environmental aspects of nanotechnology
were discussed including applications under development
in solar energy, desalination, water purification and
bioremediation. The general point was also made that
nanotechnology has the potential to create minimal waste,
no solvent chemical processes with a much enhanced and
efficient use of materials.
It was noted that new nanoparticles might impact on
the environment during manufacture, use or disposal.
It was suggested that one reasonably close to market
application was the use of carbon nanotubes in displays
and the environmental impacts of this were discussed.
As discussed below, while some participants were keen
to discover if nanotubes may have similar properties
to asbestos, once they are fixed in materials and unable
to become airborne, it was thought they would not present
a risk. However, depending on the results of toxicity
studies, disposal or recycling of products containing
nanotubes may need to be carefully controlled to ensure
containment.
Although the majority of attendees were not toxicologists,
they were keen to discuss the issue of toxicity . They
were aware that there are important adverse health effects
of inhalation of asbestos fibres, and the similarity
at least in shape was noted with carbon nanotubes. It
was noted that in general, any long thin durable fibre
is likely to cause similar effects to asbestos, unless
it has an intrinsic property such as solubility in lung
fluid making it less inherently toxic. The participants
would like to see further study into the potential durability
and toxicity of nanotubes.
There was less discussion on non-fibrous nanoparticles,
although it was noted that such particles (generated
by combustion and photochemistry) may be responsible
for the adverse effects of air pollution. Such effects
are likely to be dose-dependant, and this gave rise
to discussion on the problems of measurement of nanoparticles
against the background concentration of many tens of
thousands in urban air. These problems will arise both
with monitoring of control measures and with assessment
of dose for toxicological studies. It was suggested
that a trans-national effort was required to study the
toxicology of nanoparticles.
The use of nanoparticles in skin preparations such
as sunscreens was noted. It was thought that there was
little knowledge at present on issues such as transport
through the skin and toxic effects on dermal cells,
and that appropriate toxicological studies were necessary.
Thin films of nanomaterials were generally considered
to be of much less concern to health, safety and the
environment due to the fact that they are attached to
a surface and hence are much less likely to relocate
to unwanted areas. Expected and current applications
of nano-thin films included self-cleaning windows, computer
disk drives, and smart coatings.
c) Regulation
Currently, dosage of particles for regulation purposes
is defined by mass per unit volume, however this does
not take into account particle size, which when approaching
the nanometre scale can significantly affect properties
such as absorption or reactivity. Hence it is clear
that agglomeration, particle size and surface reactivity
will now have to be taken into account when deciding
the regulation of nanoparticles.
The issue of whether entirely new regulations or merely
a modification of existing ones would be sufficient
for nanoparticles remained unresolved among the participants.
The point was made however that there are many types
of nanoparticles and that they should not be treated
as a general case when deciding regulation. To resolve
this issue, further toxicological studies must be performed
in order to effectively inform regulators.
The point was also made that regulations may differ
between locales e.g. in the USA sun creams are categorised
as drugs for regulation, while in the UK they are regulated
as cosmetics.
d) Social and ethical issues
A general point was made relating to the publics’
perception and media reporting of nanotechnology. It
was felt that in order to conduct a rational debate,
a realistic projection of the potential impacts (positive
and negative) of nanotechnology must be communicated
to the public. It was felt that hyped up reports from
some scientists or writers have only served to confuse
the publics’ perception of nanotechnology. This
has caused confusion between what is fact and what is
fiction, and may create unjustified fears. Key messages
that the group felt should be put in the public domain
were that nanoparticles are not new-very small particles
have always been around, and that nanotechnology is
multidisciplinary and an enabling technology rather
than a new discipline in its own right. The best solution
to these public fears was seen as better public understanding
at a scientific level through the provision of better
science information in school and university undergraduate
curricula. The participants believed that initial progress
in nanotechnology would likely be by small incremental
steps in existing technology and products rather than
by a series of dramatic breakthroughs. Similarly, the
publics’ perception that nanotechnology is different
from other technologies is incorrect. Nanotechnology
has however prompted the collaboration of scientists
from differing fields of existing technology on a scale
that probably has not been seen before.
d) Other factors
A point was raised relating to the
publics awareness of commercial research and development
into nanotechnology. It was felt that in general, major
corporations were becoming less open to engaging the
public, and indeed their own peers, in discussion about
their nanotechnology research programs. A national strategy
which included engaging the public, and encouraging
more open discussion between peers in industry was seen
as a worthwhile recommendation for the main study.
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