Environmental Engineering Reference
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withthenanoparticles(Table
5
).IncreasedSODactivityandaverageCAT(catalase)
levels and GSH-px (Glutathione peroxidase) activities occurred in worms treated
withtheNPs(Lietal.
2011
).
Earthworms(
E. veneta
) were chronically exposed to ZnO nanoparticles at con-
centrationsof250and750mg/kgofsoil.TheZnOnanoparticleswerelesstoxic
thantheirbulkcounterparts(Hooperetal.
2011
). Effects of different concentrations
(0.1, 0.5, 1.0 or 5.0 g/kg) of TiO
2
and ZnO NPs on earthworms (
E. fetida
) were
studiedfor7days.Biochemicalactivitiesofthreebiomolecules(viz.,SOD,CAT,
and cellulose) and the content of MDA were assayed after the acute toxicity studies
andDNAdamagewasassessed(Table
5
). No significant change in the SOD activity
was observed, whereas CAT activity decreased with the increasing NP concentra-
tions. MDA activity increase at lower doses of NPs but a sudden decrease was
observedatthehighestNPdose(5g/kg).DNAdamageoccurredathigherdoses
(i.e.,1and5g/kg).Ofthetwonanoparticlesstudied,ZnOaccumulatedintheearth-
wormsandcausedcellularandorganelledamage(Huetal.
2010
).
5.2.2
Fish
Oberdorster(
2004
) studied the sub-lethal oxidative effects of C
60
at a concentration of
0.5mg/Lonlargemouthbass.Lipidperoxidationoccurredfromthistreatmentinbrain
after48hofexposure.MarginaldepletioninGSHlevelsofgillswasalsoobserved,
and was attributed to bactericidal action on C
60
(Table
5
)(Oberdorster
2004
).
Zhuetal.(
2008
)performeda32-daystudyonjuvenilecarp(
Carassius auratus
)
with C
60
suspensions(0.04-1.0mg/L).Nomortalityoccurred.However,asignii-
cant reduction in mean total length was observed after C
60
exposureat0.2mg/L;
moreover,reducedbodyweightoccurredat1.0mg/L(Table
5
)(Zhuetal.
2008
).
Smithetal.(
2007
) used a system approach to understand the toxicity of SWNTs
in rainbow trout.A dose-dependent rise in gill pathology (edema, altered muco-
cytes, hyperplasia), ventilation rate and mucus secretion was observed, with SWNT
precipitationoccurringingillmucus(Table
5
). Levels of Cu and Zn in brain and gill
were altered from SWNT exposure, and occurred partly from a solvent effect. A
significant decrease in thiobarbituric acid reactive substance (TBARS) in gills,
brain and liver occurred, whereas an increase in total glutathione levels in gills
(28%)andliver(18%)wasobservedfromSWNTexposure.Apoptoticbodiesand
abnormalnucleardivisionwereobservedinlivercells(Smithetal.
2007
). Similarly
TiO
2
nanoparticles elicited a respiratory response from the fish and caused sublethal
effects(Table
5
)(Federicietal.
2007
).
EffectsofAgNPsondifferentdevelopmentalstagesofJapanesemedaka(
Oryzias
latipes
) were studied (Table
5
). The 48-h LC
50
value for Japanese medaka was
1.03 mg/L. Other abnormalities observed from exposure were edema and abnor-
malitiesintheheart,ins,brain,spineandeyes(Wuetal.
2010
). The authors of this
study concluded that theAgNPs were toxic to aquatic organisms.Asharani et al.
(
2008
) reported the results of a similar study, in which starch and bovine serum
albumin (BSA) capped AgNPs were tested in zebrafish embryos (
Denio rerio
).
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