Environmental Engineering Reference
In-Depth Information
Field.low.fractionation.also.has.been.applied.to.the.analysis.of.nanoparticles.in.
soil.and.sediment.systems..Engineered.zinc.nanoparticles.have.been.separated.from.
larger.soil.particles.through.the.preparation.of.suspensions.that.are.then.shaken.and.
allowed.to.settle.gravitationally..The.supernatant,.containing.the.less.than.1-µm.par-
ticle.fraction,.was.then.separated.by.ield-low.fractionation.for.further.analysis.[50].
Analyses. of. engineered. nanoparticles. directly. in. soil. or. sediment. matrices. by.
SEM. or. TEM. imaging. techniques. is. possible. when. the. material. has. some. unique.
property,.such.as.luorescence.or.light.absorption,.or.contains.a.rare.metal.or.unique.
organic. compound. [51].. Nanoparticles. of. natural. origin. are. ubiquitous,. and. the.
detection.of.engineered.particles.against.background.using.these.techniques,.which.
are.at.best.time-consuming.and.costly,.is.not.likely.to.be.a.practical.means.of.routine.
environmental.assessments.
. nanoteChnologY MeasuReMent
ReseaRCh and FutuRe diReCtions
Both.within.the.United.States.and.internationally,.private.and.governmental.organi-
zations.have.recognized.the.need.for.improved.analytical.tools.for.nanotechnology..
The.American.Society.for.Testing.and.Materials.(ASTM) Committee E56 on Nano-
technology was formed in 2005 to develop standards and guidance for nanotechnol-
ogy and nanomaterials. The irst ASTM standard, published in July 2007, precisely.
deines.the.language.for.nanotechnology.[52]..This.should.allow.more.consistent.and.
effective.technical.communication.within.the.diverse.ields.involved.in.nanotechnol-
ogy.and.with.the.public.
In. late. 2005,. the. International. Organization. for. Standardization. (ISO). estab-
lished.a.new.technical.committee,.ISO.T/C229.Nanotechnologies,.with.three.working.
groups..The.United.States.is.represented.on.the.Measurement.and.Characterization.
Workgroup,. WG2.. The. Draft. Business. Plan. for. T/C229. [53]. details. the. high-pri-
ority. needs. and. strategies. for. this. group.. A. limited. number. of. standards. relating.
to.nanoparticle.measurements.have.been.published,.with.several.more.in.progress..
ISO/TR.27628:2007.contains.guidelines.on.characterizing.occupational.nanoaerosol.
exposures,.with.a.discussion.of.applicable.measurement.terms..Speciic.information.
is.provided.on.methods.for.bulk.aerosol.characterization.and.single-particle.analy-
sis..Other.standards.currently.near.completion.include.N.270.TS:.Terminology.and.
deinitions.for.carbon.nanomaterials;.N.271.TS:.Format.for.reporting.the.engineered.
nanomaterials.content.of.products;.and.N.272.TR:.Guide.to.nanoparticles.measure-
ment.methods.and.their.limitations.
5.4.1 u
nited
s
tates
... niosh
In. the. United. States,. the. National. Institute. for. Occupational. Safety. and. Health.
(NIOSH).established.the.Nanotechnology.Research.Center.(NTRC).in.2004.to.coor-
dinate.and.facilitate.research.on.the.impact.of.nanotechnology.in.the.workplace..The.
NTRC.recognized.that.in.order.to.evaluate.risks,.accurate.measurement.data.would.
