Part 7. Problems, issues (including hazards) and
implications associated with
Brown's Chemistry Revision Notes NANOCHEMISTRY
Nanoscience - Nanotechnology - Nanostructures
Alphabetical keyword index for
the nanoscience pages : Index of nanoscience pages
: boron nitride *
Buckminsterfullerenes-bucky balls *
carbon nanotubes * fat nanoparticles
* fluorographene *
graphene * health and
* liposomes *
nanoscale * nanoscience *
* nanotechnology *
problems in nanomaterial use *
silver nanoparticles *
safety issues * sunscreens-sunblockers *
general survey of materials - natural & synthetic, their properties & uses
chemistry revision notes science GCSE chemistry, IGCSE chemistry, O level
& ~US grades 8, 9 and 10 school science courses or equivalent for ~14-16 year old
science students for national examinations in chemistry for topics including
nanoparticles nanoscience nanochemistry uses of nanomaterials
Part 7. Problems, issues &
implications associated with
There is no doubt that
nanochemistry is providing materials scientists and chemists with incredibly
useful atomic and molecular structures with a wide range of ingenious
However, like all new
discoveries and their applications to the world of science and technology, their
very novel nature of these new materials raises various issues and examples
are discussed below, but not in any particular order.
Potential hazard issues include cell
damage in the body and unintended pollution-catalytic effects in the
The effect of nanoparticles
on the body is difficult to predict and not easily understood and the
long-terms effects on our health and well-being are quite unknown.
Therefore any new
nanomaterial must be carefully tested to ensure it is safe to use and
minimise the risks.
Therefore, should it not be
the duty of manufacturers to indicate on the label any product containing
nanoparticles? This allows consumer choice.
There is some concern the products
containing nanoparticles are being used in commercial products before being
thoroughly tested for health and safety issues.
Neither do we know what the long-term
effects might be.
Will nanoparticles be blown or washed
away into the environment? What might this affect?
Since the properties of
nanoparticles are not as well known or as easily predicted there are worries
that nanoparticles may have
undiscovered harmful side-effects if e.g. they breathed in or orally ingested,
so there way well be health and safety issues which are not yet fully
understood and how thoroughly are these new materials tested for unwanted
Nanoparticles have a very large
surface area compared to their volume, so they are often able to react very
quickly e.g. silver nanoparticles. This makes them useful as catalysts to
reactions BUT ...
However, there is also the possibility that they might speed up reactions in
in unpredictable ways, perhaps causing illness or death.
Silver particles kill bacteria,
but they may kill 'good' non-bacterial cells or 'good' bacteria if silver
nanoparticles are inhaled or ingested.
Breathing in ANY fine or
tiny solid particles can cause irritation in the lungs and potentially
cause lung damage and cancer e.g. coal miners, quarry workers etc. can all get
diseases like silicosis, emphysema, cancer from breathing in fine dust particles.
How safe are the new sunscreens that
Can the nanoparticles be absorbed by the
body i.e. through the skin and
cause irritation or other effects on cells?
We don't really know yet whether
nanoparticles can cause cell damage in or on your body?
Can nanoparticles washed away with
commercial products like suncreams cause any environmental damage and get
into food chains?
Nanoparticles of silver can be used in
deodorants, but can they do us harm if we breathe them in?
re-aggregate i.e. club together, so chemical/physical systems must be
devised to keep them apart to retain their nanoscale properties.
Nanomaterials are more
costly to produce compared to more traditional materials but as their variety of applications
and wider use increases,
greater quantities are produced, and, according to normal economic principles, their
unit cost of production should decrease, hence their price decreases.
So there are genuine risks and
uncertainties in using the 'fruits' of nanotechnologies which are usually presented in
a positive way in the media because of their exciting potential and novel
Therefore all the
benefits, risks and drawbacks of new developments in material science such
as carbon nanotubes should be carefully evaluated.
There are genuine health
concerns and toxicity regulations are difficult apply as the properties of
nanomaterials depend on the size
In truth, there must be unknown health effects because
ALL new materials have NEW health risks.
There is concern that the human immune system
may be defenceless against particles on
This poses responsibilities for the
nanotechnology industries, which in turn, raise political issues e.g. the for informed public education
and for the public to be involved in policy discussions (I see absolutely
no evidence of this at all in 2011 in the UK).
Who should decide whether particular directions in research are pursued
and associated research funding priorities.
Some problems associated with
Chemicals in the form of tiny
nanoparticles have been shown to spread throughout a crop plant and affect
growth and soil fertility.
The agricultural use of
nanoparticles is increasing in agriculture but their environmental impact is
not well understood and the effects are not just from the use of
nanoparticles in agrichemicals, but from other environmental sources too.
Nanoparticles present in exhaust
gases from motor vehicles and some fertilisers have been shown to affect
soybean growth and the health of soil the crops are grown in. Soybean is a
crop of huge commercial importance and is the world's 5th largest crop and
is the largest source of natural edible oil and plant protein.
Bacteria in the roots of soybean
(a legume) help the absorption and production of essential nutrients.
Zinc oxide and cerium oxide
nanoparticles have been shown to affect soybean plant growth, though the
effect is small in the presence of low levels of these nanoparticles.
Cerium oxide has been shown to
completely inhibit the plants ability to fix nitrogen in the roots.
Zinc oxide nanoparticles are
toxic to mammalian cells grown under laboratory conditions but their effects
on passing through food chains is unknown.
Zinc and cerium compounds can
build up in the plants with potentially damaging effects.
Zinc oxide is a common component
in the cosmetics industry and ends up as a contaminant in the solid waste
from sewage treatment and this product is used as an organic fertiliser.
Cerium oxide is used in some
diesel fuels to improve combustion efficiency and reduce carbon/hydrocarbon
nanoparticles have been shown to harm bacteria important for plant growth,
though their effects are relatively small, how the plant is affected is not fully understood.
In the agricultural science
community there is concern that widespread
long-term use of nanoparticle may spread into the environment with
unforeseen effects on plants
and animals (including implications for the health of humans too!)
NANOSCIENCE - NANOCHEMISTRY INDEX
Introduction to nanoscience,
nanoparticles, commonly used terms explained
Part 2. Nanochemistry - introduction,
uses & potential
Uses of Nanoparticles of titanium(IV) oxide (e.g. sun
cream), fat (e.g. cosmetics), silver (e.g. medical applications)
From fullerenes & bucky balls to carbon nanotubes -
structure, properties, uses
graphene oxide and
fluorographene - structure, properties, uses
Cubic and hexagonal boron nitride BN
Problems, issues and
implications associated with
see also INDEX
Smart materials pages
A general survey of materials - natural & synthetic,
their properties & uses
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