Risk assessment of
nanotechnology
Wesley E. Smith, Ph.D.
Senior Fellow
CEEH
http://thereadingroom.epsilonfoundation.com.au/technology/nano-tech-godzilla/
Outline
What is nanotechnology?
What is the state of nanotechnology risk
assessment?
What is happening at the UW?
What is nanotechnology?
How big is a nanometer (nm)?
A humanhairdivided 100,000X
Sheet of paper is about 100,000 nmthick.
Blondhair is probably 15,000 to 50,000 nmin
diameter, butblackhair is likely to bebetween 50,000
and 180,000 nm.
Thereare 25,400,000 nmin an inch.
A nanometer is a millionth of a millimeter (10-9)
http://www.nano.gov/html/facts/whatIsNano.html
http://www.nano.gov/html/facts/The_scale_of_things.html
What is nanotechnology?
“Nanotechnology is the understanding and control of
matter at dimensions between approximately 1 and
100 nanometers, where unique phenomena enable
novel applications”
Involves multiple disciplines, including science,
engineering and technology
“Wet” –involving aqueous systems
“Dry”-surface chemistry, semiconductors
Computational-modeling nanosystems
Nanosized particles (NSPs)
Promises of Nanotechnology
Clean, secureaffordableenergy
prototypesolarpanelsoffer the possibility of
beingmoreefficient.
Likewise,
nanotechnology is beingemployed in
fuelcelldevelopment
CleanWater
variousnanomaterialshold the potential
for the detection of impurities
(pollutants, microbes, etc), as well as
removal of them
http://www.nano.gov/html/facts/home_facts.html
What is special (scary) aboutnano?
Unusualphysical, chemical, and
biologicalcharacteristics at nanoscale
Individualnanoparticleshavedifferentpropertiesthan
bulksolution
Greatersurfacearea/volume-potentiallymorereactive
Ability to manipulateindividualparticles
Currentapplications of nanotech
Nano-Care® StressfreeKhakis-(Gap)
“NanoémulsionPeauxSensibles
Calming Emulsion”-(Chanel)
“The Samsung 65-nm 8-Gbit NAND
flash (K9G8G08U0M)”-(Apple)
 Public inventory:
http://www.nanotechproject.org/inventories/consumer/
Where is nanotechnology?
http://www.nanotechproject.org/maps/mappage.html
What is the state of
nanotechnology risk
assessment?
Donanomaterialspresent a risk to
human and environmentalhealth?
The verysamephysical and chemicalcharacteristics of
nanomaterialsthatgivepromise, alsohave the potential for
peril.
Effectsarenotwellcharacterized.
Ultrafineparticles
lungmodels
(UFPs)
generallycausemoretoxicity
Reactivity of someparticlesincreases
volumeratioincreases
as
Represents a veryimportantneed for research.
in
surfacearea-
Key Words of Toxicology
Dose / Response
Hazard X Exposure = Risk
Individual Susceptibility
Key Words of Toxicology
Dose / Response
Hazard X Exposure = Risk
Individual Susceptibility
Who is at risk?
Humans
Workers
Consumers
Susceptible: elderly and children
Wildlife
Aquatic life
Terrrestial life
Ecosystem
Flora
Fauna
Biodistribution
Federal oversight
NNI has provisions for funding for environmental,
health, and safety studies (EHS)
Under the Nanoscale Science, Engineering, and
Technology subcommittee (NSET), Nanotechnology
Environmental Health Implications working group
(NEHI WG) functions as an interagency forum on
understanding potential risks of nanotech.
NNI EHS Document
Strategy for Nanotechnology-relatedEnvironmental, Health,
and SafetyResearch
In FY2006, $68 millioninvested into 246 projects at 7
agencies.
Summarizesprimaryresearchcategories:
– Instrumentation, Metrology, and AnalyticalMethods
– Nanomaterials and Human Health
– Nanomaterials and the Environment
– Human and EnvironmentalExposureAssessment
– Risk Management Methods
Strategy for Nanotechnology-related
Environmental, Health, and Safety research
Who is responsible?
1
National Institute for Standards and Technology (NIST)
 Instrumentation, metrology, and analytical methods
2
National Institutes of Health (NIH)
 Nanomaterials and human health
3
Environmental Protection Agency (EPA)
 Nanomaterials and the environment
4
National Institutes of Occupational Safety and Health (NIOSH)
 Human and environmental exposure assessment
5
Food and Drug Administration (FDA)
 Risk management (also EPA)
Role of nanotechnology-related EHS research in risk
management of nanomaterials
Key Words of Toxicology
Dose / Response
Hazard X Exposure = Risk
Individual Susceptibility
Research at the UW
Toxicology of Quantum
Dots
Kavanagh (DEOHS)
Gao (BIOE)
Multiple in vitro cell lines
Transgenic mice
Various routes of
exposure
Applications of Qdots
Medical imaging
Cancer
Diagnostics
Therapeutics
Biological imaging agent
“Tag” proteins
Monitor cellular uptake
Gao, Nature,
Why are Qdots special?
Why examine the liver?
 Primary site of xenobiotic metabolism
 Common site of toxicity
 Resident macrophages sequester
bacteria from gut
http://www.flickr.com/photos/mitopencourseware/
Architecture of liver sinusoid
http://www.flickr.com/photos/mitopencourseware/
Experimental setup
Dose-response relationships evaluated:
1.
2.
3.
4.
Uptake
Viability (MTT)
GSH levels
Cell death
Disposition of Qdots in cultured human
hepatocytes
Summary and conclusions
Qdots are sequestered by a subpopulation of cells in human
hepatocyte cultures
Stable Qdots have no effect on viability of human
hepatocytesin vitro
Thus far, this preparation of Qdots does not appear to be
hepatotoxic