Environmental Engineering Reference
In-Depth Information
table .
aPeC nanometer Measurement interlaboratory 
Comparison studies for nanoparticles
Year
Characteristic
2005
Size/diameter
2006
Surface.area,.refractive.index,.light.absorption/relection
2007
Number.and.distribution,.conductivity,.dispersion
spheres.with.diameters.of.30,.50,.and.100.nm.to.participating.laboratories..The.study.
generated. a. total. of. 32. data. sets. from. 15. participating. laboratories.. Particle. size.
measurements.were.made.using.DLS,.SEM,.TEM,.and.SPM.instrumentation..The.
results.for.the.30-nm.particles.were.satisfactory.from.all.measurements,.while.two.
measurements.for.the.50-nm.particles.and.four.for.the.100-nm.sample.fell.outside.
three.standard.deviations.of.the.mean..Measurements.taken.by.TEM.for.the.30-nm.
and.100-nm.particles.were.signiicantly.below.the.expected.diameters.and.below.the.
results.from.the.other.techniques..Samples.were.distributed.for.the.2006.studies,.and.
16.laboratories.have.reported.results,.but.these.have.not.been.made.publicly.available.
at.the.time.of.writing.
5.5  s ummary
Reliable.and.accurate.measurements.of.nanoparticle.physical.and.chemical.proper-
ties.have.been.recognized.as.critical.elements.required.for.meaningful.assessments.
of.impact.and.risk..While.numerous.technologies.do.exist,.many.challenges.to.mea-
suring.engineered.nanoparticles.in.the.environment.have.yet.to.be.addressed..The.
combination.of.their.small.size.and.the.range.of.attributes.that.may.factor.into.their.
activity. requires. a. complex. matrix. of. complementary. analyses. and. methods,. for.
many.critical.parameters.have.yet.to.be.devised.for.nanoparticles.in.environmental.
settings.. Environmental. analyses. of. nanoparticles. are. far. from. routine. or. readily.
available.at.this.point,.but.the.increased.interest.and.focus.of.governmental.agencies.
and.research.organizations.allows.for.optimism.
ReFeRenCes
.
1.. Powers,.K.W.,.M..Palazuelos,.B..Moudgil,.and.S..Roberts..2007..Characterization.of.
the.size,.shape,.and.state.of.dispersion.of.nanoparticles.for.toxicological.studies.. Nano-
toxicology, .1:42-51.
.
2.. U.S..Environmental.Protection.Agency..2007.. EPA Nanotechnology White Paper ..U.S..
EPA.100/B-07/001.
.
3.. Burleson,.D.J.,.M.D..Driessen,.and.R.L..Penn..2004..On.the.characterization.of.envi-
ronmental.nanoparticles. J. Env. Science Health, 39:2707-2753.
.
4.. Durbin,.T.D.,.J.M..Norbeck,.D.R..Cocker,.and.T..Younglove..2004..Particulate.Matter.
Mass.Measurement.and.Physical.Characterization.—.Techniques.and.Instrumentation.
for.Laboratory.Source.Testing..Final.Report.ARB.Literature.Searches.
 
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