Nanotechnology
-- or nanotech, for short -- is a new approach to industrial production, based
on the manipulation of things so small that they are invisible to the naked eye
and even to most microscopes.
Nanotech
is named for the nanometer, a unit of measure, a billionth of a meter, one one-thousandth
of a micrometer. The Oxford English Dictionary defines nanotechnology as "the
branch of technology that deals with dimensions and tolerances of less than 100
nanometers, especially the manipulation of individual atoms and molecules."
Nanotech deals in the realm where a typical grain of sand is huge (a million nanometers
in diameter). A human hair is 200,000 nanometers thick. A red blood cell spans
10,000 nanometers. A virus measures 100 nanometers across, and the smallest
atom (hydrogen) spans 0.1 nanometers.
In
the realm below 50 nanometers, the normal laws of physics no longer apply, quantum
physics kicks in and materials take on surprising new properties. Something that
was red may now be green; metals may become translucent and thus invisible; something
that could not conduct electricity may now pass a current; nonmagnetic materials
may become magnetized; insoluble substances may dissolve. Knowing the properties
of a substance in bulk tells you nothing about its properties at the nano scale,
so all nano materials' characteristics -- including hazardous traits -- must be
learned anew by direct experiment.
Nanotechnologists
foresee a second industrial revolution sweeping the world during our lifetimes
as individual atoms are assembled together into thousands of useful new products.
Few deny that new products may entail new hazards, but most nanotechnologists
say existing regulations are adequate for controlling any hazards that may arise.
In the United States, nanotech is not now subject to any special regulations and
nano products need not even be labeled. Furthermore, no one has developed a consistent
nomenclature for nano materials, so rigorous discussion of nanotech among regulators
and policymakers is not yet possible. Without consistent nomenclature, standardized
safety testing lies in the future.
No
one denies that nanotech will produce real benefits, but, based on the history
of nuclear power, biotechnology and the chemical industry, skeptics are calling
for a precautionary approach. The resulting clash of philosophies -- "Better
safe than sorry" versus "Nothing ventured, nothing gained" or even
in some cases "Damn the torpedoes, full speed ahead!" -- may offer a
major test of the Precautionary Principle as a new way of managing innovation.
"WORLD
PEACE, UNIVERSAL PROSPERITY"
The
pressure for rapid development of nanotech is enormous. The surprising properties
of materials at the nano scale have opened up a new universe of industrial applications
and entrepreneurial dreams. Largely unnoticed, hundreds of products containing
nano-sized particles have already reached the market -- metal surfaces and paints
so slick they clean themselves when it rains; organic light-emitting diodes for
computer screens, digital cameras and cell phones; sub- miniature data storage
devices (aiming to hold the Library of Congress in a computer the size of a sugar
cube); specialty lubricants; long-mileage vehicle tires; nano-reinforced plastics
for stronger automobile fenders; light-weight military armor; anti-reflective
and scratch-resistant sun glasses; super-slippery ski wax; powerful tennis rackets
and long-lasting tennis balls; inkjet photographic paper intended to hold an image
for 100 years; high-contrast MRI scanners for medical diagnosis; efficient drug
and vaccine delivery systems; vitamins in a spray; invisible sunscreen ointments
containing nano particles of titanium or zinc; anti-wrinkle cosmetic creams; and
so on.
And
this is just the beginning. Nanotech wasn't possible until the invention in the
1980s and early 1990s of ways to arrange individual atoms under software control.
Nano particles, nanotubes and carbon nano crystals called Bucky Balls (after Buckminster
Fuller) are now being manufactured in ton quantities for industrial use. Currently
technologists are working feverishly to coax nature's most successful nano factory,
the living cell, to grow useful new nano assemblies. It is no exaggeration to
say that the field of nanotech is gripped by something approaching a gold rush
mentality. Worldwide, governments are spending an estimated $3 billion per year
on nanotech research, and the private sector is thought to be spending at least
that much. The U.S. government alone will spend at least $3.7 billion on nano
R&D during the next four years. The global market for nano products is expected
to reach $1 trillion in 10 years or less. Any day of the week you can check in
at http://nanotech-now.com and catch a glimpse of the gold rush in action.
But
for some prominent proponents of nanotech, this is about more than money -- it
is about reinventing the entire world, including humans, as they now exist. According
to the U.S. National Science Foundation, nanotechnology is the foundation stone
of NBIC -- a revolutionary convergence of nanotech, biotech (manipulation of genes),
info tech (computers), and cogno tech (brain function). In a report sponsored
by the National Science Foundation and the Department of Commerce, the technologists
and politicians who are promoting this revolution say it is "essential to
the future of humanity" because it holds the promise of "world peace,
universal prosperity, and evolution to a higher level of compassion and accomplishment."
They say it may be "a watershed in history to rank with the invention of
agriculture and the Industrial Revolution." The ultimate aim of this revolution
has been an explicit human goal for at least 400 years -- the "conquest of
nature" and the enhancement of human capabilities.
Whatever
else it may offer, the nanotech revolution entails a radical new approach to industrial
production with the potential to change every existing industry, plus create new
ones. Typical manufacturing today -- even construction of the tiniest computer
circuit -- relies on "top-down" techniques, machining or etching products
out of blocks of raw material. For example, a common technique for making a transistor
begins with a chunk of silicon, which is etched to remove unwanted material, leaving
behind a sculpted circuit. This "top-down" method of construction creates
the desired product plus waste residues.
In
contrast, nanotech makes possible "bottom-up" construction in which
atoms are arranged under software control -- or in ideal cases they will self-assemble,
just as living cells self-assemble -- into the desired configuration with nothing
left over, no waste. Instead of cutting trees into lumber to make a table, why
not just "grow" a table? Thus nanotech seems to offer the possibility
of waste-free manufacturing and therefore a cleaner environment. Furthermore,
nanotech may help remediate past pollution. U.S. Environmental Protection Agency
(EPA) is funding research on releasing nano particles into the environment to
detoxify mountains of toxic waste remaining from the 20th century's experiment
with petroleum-based chemistry.
INSURING
A NANOTECH FUTURE
Nevertheless,
without denying plausible benefits, critics want nanotech's potential problems
brought into the open:
**
Unless nanotechnology is shared generously, it may create a "nano divide"
similar to the "digital divide" that exists now between those with ready
access to computers and those without.
**
Humans given enhanced mental or physical capabilities may gain great advantage
over normal people. On the other hand, some people may be coerced to accept dubious
or unwanted enhancements.
**
Inequalities within and between nations may be exacerbated if individuals and
corporations gain monopoly control of nanotech by patenting the building blocks
of the universe -- a precedent set in 1964 when Glenn T. Seaborg was issued a
patent on an element he discovered and named Americium.
In
the longer term, some leading technologists like Ray Kurzweil, inventor of the
first reading machine for the blind, and Bill Joy, one of the founders of Sun
Microsystems, fear that nanotech will give individuals -- inadvertently or intentionally
-- destructive potential greater than the power of atomic weapons. As Joy wrote
in 2000, "I think it is no exaggeration to say we are on the cusp of the
further perfection of extreme evil, an evil whose possibility spreads well beyond
that which weapons of mass destruction bequeathed to the nation-states, on to
a surprising and terrible empowerment of extreme individuals."
Others,
such as the insurance industry, have more mundane concerns about nanotech -- chiefly,
the potential health and environmental hazards of tiny particles. In May of 2004,
Swiss Re, the world's second-largest reinsurance firm, issued a report calling
for the Precautionary Principle to guide nanotech development. Swiss Re itemized
a host of potential problems that it says need to be resolved before nanotech
products are fully deployed, including these:
**
One of the new properties of nano-sized particles is their extreme mobility. They
have "almost unrestricted access to the human body," Swiss Re points
out, because they can enter the blood stream through the lungs and possibly through
the skin, and seem to enter the brain directly via olfactory nerves. Once in the
blood stream, nano particles can "move practically unhindered through the
entire body," unlike larger particles that are trapped and removed by various
protective mechanisms.
**
If they become airborne, nano particles can float for very long periods because
-- unlike larger particles -- they do not readily settle onto surfaces. In water,
nano particles spread unhindered and pass through most available filters. So,
for example, current drinking water filters will not effectively remove nano particles.
Even in soil, nano particles may move in unexpected ways, perhaps penetrating
the roots of plants and thus entering the food chains of humans and animals.
**
One of the most useful features of nano particles is their huge surface area.
The smaller the particle, the larger its surface in relation to its mass. A gram
of nano particles has a surface area of a thousand square meters. Their large
surfaces give nano particles some of their most desirable characteristics. For
example, drug-coated nano particles may one day transport pharmaceuticals directly
to specific sites within the human body. Unfortunately, their large surface also
means that nano particles may collect and transport pollutants.
Furthermore,
their large surface means nano particles are highly reactive in a chemical sense.
As Swiss Re noted, "As size decreases and reactivity increases, harmful effects
may be intensified, and normally harmless substances may assume hazardous characteristics."
Nano particles may harm living tissue, such as lungs, in at least two ways --
through normal effects of chemical reactivity, or by damaging phagocytes, which
are scavenger cells that normally remove foreign substances. Phagocytes can become
"overloaded" by nano particles and cease functioning. Worse, overloaded
phagocytes retreat into deeper layers and so become unavailable to protect against
foreign invaders. Successive particles are then able to do their full reactive
damage, and other invaders, such as bacteria, may penetrate unhindered. The surface
reactivity of nano particles gives rise to "free radicals," which are
atoms containing an "unsatisfactory" number of electrons (either too
few or too many for stability). Free radicals swap electrons with nearby atoms,
creating further instabilities and setting off a cascade of effects. Free radicals
give rise to inflammation and tissue damage, and may initiate serious harm, such
as growth of tumors. On the other hand, some free radicals are beneficial, destroying
invaders. So the role of nano particles in producing free radicals remains to
be clarified.
**
Nano particles would normally tend to clump together, forming larger, less dangerous
particles -- but nanotechnologists take pains to prevent clumping by adding special
coatings. As a result, nano particles in many commercial products, sprays and
powders remain reactive and highly mobile.
**
Whether nano particles can pass through the skin into the blood stream is the
subject of intense debate. Different experiments have yielded conflicting results,
presumably because test protocols have not been standardized. Some believe that
nano particles may slip between the layers of outer skin and penetrate through
to the blood below. Others believe that hair follicles offer a direct route for
nano particles to penetrate from skin to blood. No one knows for sure. Despite
this knowledge gap, sun screens, skin lotions and baby products containing nano
particles are already on the market. Clearly this is a problem for insurance firms
providing liability coverage. Swiss Re says, "Considering the wide variety
of products already on the market, the need for a solution is urgent."
**
Ingested nano particles can be absorbed through "Peyer's plaques," part
of the immune system lining the intestines. From there, nano particles can enter
the blood stream, be transported throughout the body, "and behave in ways
that may be detrimental to the organism," Swiss Re notes. While in the blood
stream, nano particles have been observed entering the blood cells themselves.
**
Once in the body, nano particles can enter the heart, bone marrow, ovaries, muscles,
brain, liver, spleen and lymph nodes. During pregnancy, nano particles would likely
cross the placenta and enter the fetus. The specific effects in any given organ
would depend upon the surface chemistry of particular particles, which in turn
would be determined by their size and surface coating. "It is likely that
in the course of its entire evolution, humankind has never been exposed to such
a wide variety of substances that can penetrate the human body apparently unhindered,"
Swiss Re says.
**
The brain is one of the best-protected of all human organs. A guardian "blood-brain
barrier" prevents most substances in the blood from entering the brain (alcohol
and caffeine being two well-known exceptions). However, nano particles have repeatedly
been shown to pass into the brain, where their effects are unknown. Will they
accumulate and, if so, to what effect?
**
Nano particles may disrupt the immune system, cause allergic reactions, interfere
with essential signals sent between neighboring cells, or disrupt exchanges between
enzymes, Swiss Re says. Some of these characteristics may be harnessed for benefit
-- for example, in experiments a carbon nano crystal has been able to disrupt
one of the processes that allows the AIDS virus to multiply.
**
Nano particles in disposable products will eventually enter the environment. In
the environment, nano particles represent an entirely new class of pollutants
with which scientists (and nature) have no experience. Swiss Re speculates that,
"Via the water cycle, nano particles could spread rapidly all over the globe,
possibly also promoting the transport of pollutants." Swiss Re asks, "What
would happen if certain nanoparticles did exert a harmful influence on the environment?
Would it be possible to withdraw them from circulation? Would there be any way
of removing nanoparticles from the water, earth, or air?"
**
Turning to workplace hazards, Swiss Re asks whether nano particles will become
the next asbestos. To protect workers, effective face masks are "not a very
realistic prospect at present, since the requisite design would render normal
breathing impossible." New designs may be possible but remain unproven.
PRECAUTION
ON A SUPER-SMALL SCALE
Swiss
Re notes that, in the past, the drive toward rapid technological innovation has
"prevented the introduction of the Precautionary Principle in relation to
new technologies for more than 20 years." But now, "in view of the dangers
to society that could arise out of the establishment of nanotechnology, and given
the uncertainty currently prevailing in scientific circles, the Precautionary
Principle should be applied whatever the difficulties," Swiss Re asserts.
"The Precautionary Principle demands the proactive introduction of protective
measures in the face of possible risks, which science at present -- in the absence
of knowledge -- can neither confirm nor reject."
What
would precaution look like in a rapidly developing field like nanotech? The British
Royal Society and the Royal Academy of Engineering issued a nanotech report in
July 2004 recommending a series of precautionary actions, with the following chain
of reasoning:
**
"The evidence we have reviewed suggests that some manufactured nanoparticles
and nanotubes are likely to be more toxic per unit mass than particles of the
same chemicals at larger size and will therefore present a greater hazard."
**
"There is virtually no evidence available to allow the potential environmental
impacts of nanoparticles and nanotubes to be evaluated."
**
Therefore, "the release of nanoparticles to the environment [should be] minimized
until these uncertainties are reduced."
**
And, "until there is evidence to the contrary, factories and research laboratories
should treat manufactured nanoparticles and nanotubes as if they were hazardous
and seek to reduce them as far as possible from waste streams."
These
recommendations reverse the traditional approach to industrial materials, which
have historically been assumed benign until shown otherwise.
The
Royal Society puts the burden of producing information about safety on industry,
not on the public: "A wide range of uses for nanotubes and nanoparticles
is envisaged that will fix them within products.... We believe that the onus should
be on industry to assess ... releases [of nano particles from products] throughout
a product's lifetime (including at the end-of-life) and to make that information
available to the regulator." From such a recommendation, it is a very short
step to the European Union's precautionary proposal for industrial chemicals,
called REACH (Registration, Evaluation and Authorization of Chemicals), which
is often summarized as, "No data, no market."
The
Royal Society recommended that the use of zinc oxide nano particles and iron oxide
nano particles in cosmetics should "await a safety assessment" -- in
other words a moratorium on these products is recommended. Likewise, "the
release of free manufactured nanoparticles into the environment for [pollution]
remediation (which has been piloted in the USA) should be prohibited until there
is sufficient information to allow the potential risks to be evaluated as well
as the benefits."
The
Precautionary Principle is sometimes called the foresight principle. Importantly,
the Royal Society's report fully embraces foresight for nanotechnology (and all
other new technologies): "Our study has identified important issues that
need to be addressed with some urgency" and so it is "essential"
for government to "establish a group that brings together representatives
of a wide range of stakeholders to look at new and emerging technologies and identify
at the earliest possible stage areas where potential health, safety, environmental,
social, ethical and regulatory issues may arise and advise about how these might
be addressed." The group must provide "an early warning of areas where
regulation may be inadequate for specific applications of these technologies."
And, finally, "The work of this group should be made public so that all stakeholders
can be encouraged to engage with the emerging issues."
Thus
nanotech is sparking not only a new industrial revolution but demands for a reversal
of traditional approaches to managing innovation and a turn toward precautionary
action. Whether the momentum gathering behind the precautionary approach can redirect
the charge behind nanotech -- a confluence of government and technophile advocates
in alliance with an emerging industrial lobby -- remains uncertain.
Note:
This article originally appeared in The Multinational Monitor Vol. 25, No. 9 (September,
2004), pgs. 16-19, under the title, "Welcome to NanoWorld: Nanotechnology
and the Precautionary Principle Imperative."
RACHEL'S
ENVIRONMENT & HEALTH NEWS Environmental Research Foundation P.O.
Box 160 New Brunswick, N.J. 08903 Fax (732) 791-4603; E-mail: erf@rachel.org
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