Civil Engineering Reference
In-Depth Information
Table 7.2
Continued
Nanomaterial
Observed toxicological effects
SiO
2
nanoparticles
Antibacterial
ROS toxicity
Cell enlargement in microorganisms
Reduction in photosynthetic pigment content
Infl ammatory and immune responses
Apoptosis
Up-regulation of tumor necrosis factor (alpha genes)
Nanoclays
Intracellular ROS formation in human cells
Cell membrane damage
Enhanced numbers of multinucleated
macrophage-agglomerates
Quantum dots
Bacterial toxicity due to metal release
Lipid peroxidation
Oxidative stress
Transmembrane activity and proteolysis involving
proteasome activation and ubiquitin-mediated
processes
Particle uptake
DNA damage
Multiple organelle damage
Metal accumulation in liver, kidneys, and spleen
in construction. The reader should keep in mind that the fi eld is very much
in fl ux and thus our tables are unlikely to be comprehensive. We discuss
some of the nanotoxicological issues of individual classes of MNMs in order
to demonstrate the range of different toxicity paradigms that can be encoun-
tered when dealing with different MNM classes.
7.2.1 Carbon-based nanomaterials
Frequently used MNMs containing primarily carbon atoms enclosing a
hollow interior include carbon nanotubes (CNTs) and fullerenes such as
C
20
, C
60
, and
C
60
derivatives. Specifi cally, carbon nanotubes, C
60
fullerenes,
and C
60
derivatives are currently raising health concerns as they have been
shown to have adverse effects on bacterial, mammal and human cells (Jia
et al.
, 2005; Park
et al.
, 2010). CNTs are frequently contaminated with heavy
metals, which is due to their particular production process. This brings up a
common issue of MNMs: MNMs can be contaminated with other elements
that might have toxicological relevance. Stringent quality control of the
nanomaterials for such contaminations is essential.
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