Overview of Nanoscience in the Environment - Environmental and Human Health Impacts of Nanotechnology - page 10

• Combining nanotechnology with biotechnology will enable repair or replace-
ment of defective cellular components such as protein signalling receptors (Roco
and Bainbridge, 2003 ).
• Establishment of direct links between neuronal tissue and machines that would
allow direct control of mechanical, electronic and even virtual objects as if they
were extensions of human bodies by brain - to - brain and brain - to - machine inter-
faces (Roco and Bainbridge, 2003).
• Continuous health monitoring and semi-automated treatment using small and
cheap sensors and other implantable devices (Roco and Bainbridge, 2003).

1.8 Potential Adverse Effects of Nanomaterials

Nanotechnology can be used for harmful, as well as for benefi cial, purposes and
examples include in weapon construction (Glenn, 2006). Apart from the direct use
of nanomaterials for harmful purposes, the rapid growth of nanotechnology indus-
try will inevitably increase the concentration of nanomaterials in the environment,
with potential consequence for human and environmental exposure. There are few
studies on the effect of nanoscale materials on the environment or health, in part
because of our inability to reliably quantify the concentration of nanoparticles in
the environment (Chapter 6). Results are still inconclusive and the gaps in our
knowledge of the environmental, health and safety implications associated with
nanomaterials are large (Royal Society and Royal Academy of Engineering, 2004).
Hence, it is not yet possible to draw any broad conclusions about which nanoma-
terials may pose hazard and/or risk. Nanomaterials may affect the environment and
human health in different ways, as described below.

1.8.1 Environmental

Although less studied than human health, there is also cause for concern regarding
environmental impacts, and areas such as ecotoxicology, environmental chemistry
and fate and behaviour are areas of intense current research. Nanomaterials may
potentially impact the environment in three possible ways: (i) direct effect on
micro - organisms, invertebrates, fi sh and other organisms; (ii) interaction with con-
taminants, that may change the bioavailability of toxic compounds and/or nutrients;
and (iii) changes to non-living environmental structures.

1.8.1.1 Toxicity of Nanomaterials

The majority of current studies of the toxicity of nanomaterials have been per-
formed on a limited number of nanomaterials and aquatic species, usually at high
concentration and over short exposure periods (Nowack and Bucheli, 2007). There
are few, if any, chronic, full life cycle or multigenerational studies available. An early
study of fullerenes (C 60 ) has shown that they induce oxidative stress in the brain of
juvenile largemouth bass without a clear concentration dose- response relation
(Oberdorster, 2004). Nanoclusters of C 60 have been shown to generate reactive
oxygen species in water under UV and polychromatic light. Fullerenol (C 60 (OH) 24 )