Nanotechnology in Food & Agriculture - denix

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than 100nm. However given the evidence
of nano-specific biological behaviour
and related toxicity risks associated with
particles a few hundred nanometres in
size, Friends of the Earth urges regulators
responsible for assessing and managing
the health and environmental risks of
nanoparticles to require particles up
to 300nm in size to be subject to nanospecific
safety testing and regulation prior
to being permitted for commercial use in
food and agricultural products.
Manufactured vs. incidental
nanoparticles
‘Manufactured’ nanomaterials are those
which are produced deliberately. They
include nanoparticles (e.g. metal oxides
such as zinc oxide and titanium dioxide),
as well as structures created through
nanotechnology such as nanotubes,
nanowires, quantum dots, dendrimers and
carbon fullerenes (buckyballs), among
others (see glossary).
In comparison, ‘incidental’ nanoparticles
are nanoparticles which are not
manufactured deliberately, but either
occur in nature or as a byproduct of
industrial processes. Sources of incidental
nanoparticles, also called ultrafine
particles in the study of air pollution,
include forest fires and volcanoes, and
high-temperature industrial processes
such as combustion, welding, grinding
and exhaust fumes of cars, trucks and
motorcycles (U.K. HSE 2004). Although
humans have historically been exposed
to small numbers of these incidental
nanoparticles, until the industrial revolution
this exposure was quite limited.
The emerging field of nanotoxicology
(the study of the risks associated with
manufactured nanomaterials) is being
informed by our understanding of risks
associated with incidentally produced
nanoparticles. For example, we know
that exposure to large levels of incidental
nanoparticles in urban air pollution causes
increased incidence of disease and even
death among vulnerable sections of the
population (Yamawaki and Iwai 2006).
| NANOTECHNOLOGY IN FOOD & AGRICULTURE
In this report, Friends of the Earth focuses
on manufactured nanomaterials used
in food and agriculture. However we
recognise that the presence of incidental
nanomaterials in foods, for example as a
result of the wear from food processing
equipment, could also pose new health
risks which warrant consideration by
regulators.
The need to investigate the health and
environmental implications of other
small particles
Preliminary evidence suggests
that although these particles may
be thousands of times larger than
nanoparticles, small microparticles around
1-20µm in size (1,000 – 20,000nm) may
also pose health risks. Microparticles
do not have the same bioavailability
of nanoparticles and they cannot be
taken up by individual cells. They are also
comparatively less chemically reactive
and bioactive than nanoparticles, and
bioactive than nanoparticles. However
the reactivity and bioavailability of
microparticles remain far greater than
that of larger particles (Sanguansri and
Augustin 2006). Studies using rats have
demonstrated gastrointestinal uptake of
particles measuring up to 20µm in size,
mainly via Peyer’s Patches in the small
intestine (Hagens et al. 2007). Pathology
studies also suggest that microparticles up
to 20µm in size are taken up through the
human gastro-intestinal tract, translocated
through the body, and accumulate in
secondary organs where they may be
associated with long-term pathological
damage, for example the development
of granulomas and lesions (Ballestri et al.
2001; Gatti and Rivassi 2002). Granulomas
and lesions can have serious longterm
health effects, leading to chronic
inflammation and even cancer. Beyond
the need for nanotechnology-specific
regulation for nanomaterials in foods and
food contact materials, Friends of the
Earth therefore also urges regulators to
investigate the need for appropriate new
safety assessments of small microparticles.