Environmental Engineering Reference
In-Depth Information
nanomaterials.into.solution.also.eliminate.the.self-purifying.mechanisms.of.natural.
waters.such.as.adsorption,.complexation,.precipitation,.and.deposition..These.nano-
materials.may.tend.to.agglomerate.or.oxidize,.particularly.over.time,.which.further.
affects. bioassay. results.. In. the. review. of. the. references. cited. in. Table.8.1,. it. also.
becomes.clear.that.nanomaterials.may.become.contaminated.with.byproducts.that.
are.generated.in.their.production.
Based. on. traditional. laboratory. aquatic. bioassays,. the. relative. hazard. of. the.
nanomaterials.tested.thus.far.appears.to.be.in.the.“low.to.moderate”.range..Given.
that. environmental. conditions. are. certainly. not. uniform. in. the. ield,. the. bioassay.
results.suggest.that.the.subset.of.nanomaterials.including.carbon-based.fullerenes,.
single-.and.multi-walled.nanotubes,.carbon.black,.and.titanium.dioxide.will.pose.a.
relatively.low.hazard.to.native.aquatic.organisms..One.exception.to.this.may.be.col-
loidal.silver,.which.is.both.soluble.in.water.and.contains.silver,.a.known.toxicant.to.
aquatic.organisms.
. ReCoMMendations FoR Managing the Risks oF
FutuRe nanoMateRials and theiR PRoduCtion
As.the.research.described.in.this.chapter.shows,.some.nanomaterials.may.be.toxic.to.
ecological.receptors,.but.the.hazard.is.anticipated.to.be.limited.by.fate.and.transport.
processes.that.restrict.exposure..Economics.also.may.limit.the.release.of.nanomate-
rials.to.the.environment.during.manufacturing,.as.manufacturers.seek.to.minimize.
product.losses.during.production..The.use.of.known.toxics.to.produce.nanomaterials.
may.present.other.concerns,.however,.as.discussed.further.in.Chapter.11.
Although.many.scientists.are.concerned.about.the.containment.and.the.potential.
risks.associated.with.both.current.and.future.nanomaterials,.it.is.possible.that.these.
risks.can.be.managed.using.existing.technology..But.the.oft-quoted.phrase.“those.
that. ignore. history. are. doomed. to. repeat. it”. may. hold. true. if. there. is. little. to. no.
communication.between.scientists.(particularly.between.toxicologists.and.industrial.
hygienists.with.research.scientists.who.are.inventing.these.materials.at.a.rapid.rate),.
regulators,.and.the.public..It.would.be.prudent.to.treat.each.new.nanomaterial.in.the.
same.way.society.treats.each.new.chemical.compound,.and.the.only.way.to.do.that.
is.through.the.use.of.a.carefully.selected.battery.of.tests.and.bioassays..That.said,.
it. also. will. be. important. to. ensure. that. an. industry. standard. is. used. for. the. mass.
production.of.the.more.commonly.used.nanomaterials.so.that.testing.regimes.and.
results.from.laboratory.to.laboratory.can.be.compared.with.conidence.
ReFeRenCes
.
1.. Treverton,.G.F..2007..Risks.and.riddles..In.“People.and.Culture,”.
Smithsonian Maga-
zine
..http://www.smithsonianmagazine.com/issues/2007/june/presence-puzzle.php.
.
2.. Knight,. T.,. V.G.R.. Chada,. S.S.. Wise,. et. al.. 2007.. Cell-based. assay. for. cytotoxic. and.
pro-inlammatory.effects.of.gold.nanoparticles..
NSTI-Nanotech 2007
,.2..http://www.
nsti.org/procs/Nanotech2007v2/7.
.
3.. International.Agency.for.Research.on.Cancer.(IARC)..1996..Summaries.and.Evalua-
tion:.Carbon.Black.65:149..http://www.inchem.org/documents/iarc/vol65/carbon.html..
(Accessed.September.29,.2007)
