Risk assessment of nanotechnology

Wesley E. Smith, Ph.D.Senior FellowCEEHhttp://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

http://www.nano.gov/html/facts/home_facts.html

CleanWater

variousnanomaterialshold the potential for the detection of impurities (pollutants, microbes, etc), as well as removal of them

What is special (scary) aboutnano?

Unusualphysical, chemical, and biologicalcharacteristics at nanoscale

Individualnanoparticleshavedifferentpropertiesthanbulksolution

Greatersurfacearea/volume-potentiallymorereactive

Ability to manipulateindividualparticles

Currentapplications of nanotech

Nano-Care® StressfreeKhakis-(Gap)

“NanoémulsionPeauxSensiblesCalming 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 (UFPs) generallycausemoretoxicity in lungmodels

Reactivity of someparticlesincreases as surfacearea-volumeratioincreases

Represents a veryimportantneed for research.

Key Words of Toxicology

Hazard X Exposure = Risk

Individual Susceptibility

Dose / Response

Key Words of Toxicology

Hazard X Exposure = Risk

Individual Susceptibility

Dose / Response

Who is at risk?Humans

Workers

Consumers

Susceptible: elderly and children

WildlifeAquatic life

Terrrestial life

EcosystemFlora

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 DocumentStrategy 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 researchWho 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

Hazard X Exposure = Risk

Individual Susceptibility

Dose / Response

Research at the UW

Toxicology of Quantum Dots

Kavanagh (DEOHS)

Gao (BIOE)

Multiple in vitro cell lines

Transgenic miceVarious routes of exposure

Applications of Qdots

Medical imagingCancer

Diagnostics

Therapeutics

Biological imaging agent

“Tag” proteins

Monitor cellular uptake

Gao, Nature,

Why are Qdots special?

Why examine the liver?

http://www.flickr.com/photos/mitopencourseware/

Primary site of xenobiotic metabolism

Common site of toxicity Resident macrophages

sequester bacteria from gut

Architecture of liver sinusoid

http://www.flickr.com/photos/mitopencourseware/

Experimental setup

Dose-response relationships evaluated:

1. Uptake2. Viability (MTT)3. GSH levels4. 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