Biomedical Engineering Reference
In-Depth Information
TABLE 7.2
Common Environmental Contaminants Transformed by SPs
Inorganic Contaminants
Organic Contaminants
Ammonia (NH 3 ), azide ions
N ( ) , chromium (Cr)
species, copper (Cu),
cyanide ions (CN ), gold
(Au), halide ions (i.e.,
fluoride [F ], chloride [Cl ],
bromide [Br ], iodide [I ],
astatide [At ]), iron (Fe)
species, manganese (Mn)
species, nitrates NO
Chlorinated aromatics (e.g., chlorophenols, chlorobenzenes,
chlorobiphenyls, dichlorodibenzo- p -dioxin, chlorodibenzo-
p -dioxin, 2,4,5-trichlorophenoxyacetic, acid,
2,4-dichlorophenoxyacetic acid), polychlorinated biphenyls
(PCBs) (C 12 H 10 -x Cl x ), dichlorodiphenyltrichloroethane
(DDT) (C 14 H 9 C l5 ), chlorinated surfactants, chlorinated
ethenes (e.g., tetrachloroethene [C 2 Cl 4 ], trichloroethene
[C 2 HCl 3 ], cis -dichloroethene [C 2 H 2 Cl 2 ], trans -dichloroethene
[C 2 H 2 Cl 2 ], dichloroethene [C 2 H 2 Cl 2 ], vinyl chloride
[C 2 H 3 Cl]), Nitrogenous compounds (e.g., monuron,
nitrotolulene, picoline, piperidene, proline, pyridine,
simazine, theophylline, thymine, trietazine,
cyclophosphamide, ethylenediaminetetraacetic acid
[EDTA]), etc.
( ) and
nitrites NO ( ) , nitric oxide
(NO), ozone (O 3 ), palladium
(Pd), silver (Ag) and sulfur
(S) species, etc.
Source:
Modified after Hoffmann M.R. et al., Chem. Rev. , 95, 69, 1995.
of the nanotubes to destroy toluene was tested by Chen et al. [33] and the
results showed that they exhibit much higher destruction rates than the non-
nanotube material [33].
Along with the benefits associated with the utilization of TiO 2 for environ-
mental remediation, it is possible that TiO 2 NPs, injected in the underground,
can cause environmental problems and/or do harm to human health.
Currently, little data regarding the human and environmental exposure to
TiO 2 NPs, used for environmental remediation, are available and the associ-
ated risks are still largely unknown.
Several models describing how TiO 2 NPs behave in the environment have
been developed thus far, as most of them point out that it is very likely that in
situ applied TiO 2 particles reach surface waters [34,35]. According to Mueller
and Nowack [34], among all NPs, TiO 2 was of largest environmental con-
centration in the Swiss surface waters (i.e., 16 μg L -1 ). This was confirmed
by Boxall et al. [35], who suggested a nano-TiO 2 concentration of 24.5 μg L -1
in the British surface waters [35]. From the water, the TiO 2 particles can be
easily taken up by living organisms and enter the human food chain. Once
there, they might potentially cause adverse health effects in the exposed
populations. These effects, however, are still largely unexplored. To assess
the health risks of exposure to TiO 2 NPs, it is essential to investigate their
toxicity more deeply.
7.4.1.3 Polymeric Nanoparticles
Polymeric NPs are a very broad category of molecules and molecular aggre-
gates suitable for a variety of applications. They have amphiphilic properties,
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