Biomedical Engineering Reference
In-Depth Information
TABLE 26.1
Phytoxicity.of.Various.Nanoparticles.on.Plants
MWNT
Aluminum
Alumina
Nano-Zinc
Nano-ZnO
10-20
nm
diameter
60nm
20nm
18nm
35nm
Seed
Root
Seed
Root
Seed
Root
Seed
Root
Seed
Root
Radish
+
+
+
+
+
+
+
50.mg/L
+
50.mg/L
Rape
20.mg/L
20.mg/L
+
+
+
+
+
+
+
+
Ryegrass
2.g/L
20.mg/L
20.mg/L
+
+
+
+
+
+
+
Lettuce
+
+
+
2.g/L
2.g/L
+
+
+
+
+
Corn
2.g/L
2.g/L
2.g/L
+
+
+
+
+
+
+
Cucumber
2.g/L
2.g/L
+
+
+
+
+
+
+
+
Note:
. MWNT.=.multiwalled.carbon.nanotubes,.+.=.no.observed.toxicity,.numerical.value.=.IC
50
.
In.a.relatively.early.publication.appearing.in.2007,.Lin.and.Xing.reported.a.study.of.ive.
types.of.nanoparticles.in.six.different.plant.systems.
17
.Phytotoxicity.studies.of.multiwalled.
carbon.nanotubes.(MWNTs),.as.well.as.nanoparticle.aluminum,.alumina,.zinc,.and.zinc.
oxide,. on. seed. germination. and. root. growth. of. six. plant. species. (radish,. rape,. ryegrass,.
lettuce,.corn,.and.cucumber).were.examined.(Table 26.1).
Most.nanoparticles.showed.little.effect.in.these.systems,.except.for.nano-Zn.and.nano-
ZnO.
17
.Seed.germination.was.not.affected,.except.for.the.inhibition.by.nano-Zn.on.ryegrass.
and.nano-ZnO.on.corn.at.2,000.mg/L..On.the.other.hand,.inhibition.of.root.growth.var-
ied. greatly. among. nanoparticles. and. plants.. The. 50%. inhibitory. concentrations. (IC
50
). of.
nano-Zn.and.nano-ZnO.were.estimated.to.be.near.50.mg/L.for.radish.and.20.mg/L.for.
rape.and.ryegrass..These.results.suggested.signiicant.environmental.effects.could.result.
from.inappropriate.use.and.disposal.of.such.engineered.nanoparticles.
A.more.recent.study.reported.a.comprehensive.survey.of.a.number.of.different.nano-
particle.materials.in.comparison.with.its.non-nano.bulk.material.
18
.This.study.compared.
some. data. from. ive. typical. nanoparticles. using. three. different. test. systems. to. evaluate.
toxicity..The.irst.test.examined.the.effects.on.zucchini.seed.germination.of.the.presence.
or.absence.of.test.compounds,.using.both.the.nanoparticles.and.the.corresponding.bulk.
materials. (Table 26.2).. In. data. from. the. paper,. a. wide. variation. was. observed. when. the.
nanomaterials.were.dispersed.using.a.surfactant..There.seemed.to.be.more.of.an.effect.on.
the.surfactant.sodium.dodecyl.sulfate.(SDS).than.on.the.compounds.tested,.and.dificulty.
in.testing.water-insoluble.materials.
A.second.test.involved.effects.of.test.materials.on.root.growth,.with.few.effects.observed.
for. any. material.. The. inal. test. used. overall. biomass. to. assay. effects. on. plant. growth..
These. data. were. somewhat. dificult. to. assess. quantitatively. because. of. the. dificulty. in.
determining.the.concentrations.of.nanoparticle.metals,.compared.with.metal.ions..One.
interesting.result,.however,.is.shown.in.Figure 26.3,.wherein.the.effect.of.multiwall.carbon.
TABLE 26.2
Effect.of.Nanomaterials.on.Plants:.Percent.Zucchini.Seed.Germination.of.Bulk.vs..Nanomaterials
Water
Control
Activated
Carbon
ZnO
Powder
ZnO
5nm
ZnO
10nm
Si
Powder
Si
100nm
Cu
Powder
Cu
50nm
Ag
Powder
Ag
100nm
MWNT
90
60
40
67
86
67
40
0
40
53
67
33
