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“There’s Plenty of Room at the Bottom” – but is is safe to go there?

“There’s Plenty of Room at the Bottom” – but is is safe to go there?. Larry Gibbs, CIH Associate Vice Provost Environmental Health & Safety Stanford University. Overview. Nanotechnology – background and growing importance Assessing, managing and communicating about nanomaterial risk

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“There’s Plenty of Room at the Bottom” – but is is safe to go there?

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  1. “There’s Plenty of Room at the Bottom” – but is is safe to go there? Larry Gibbs, CIH Associate Vice Provost Environmental Health & Safety Stanford University

  2. Overview • Nanotechnology – background and growing importance • Assessing, managing and communicating about nanomaterial risk • Recommendations to address risks

  3. Nanotechnology vision “There’s plenty of room at the bottom.” -Richard Feynman, December 29, 1959 “Plenty of room at this bottom” -Topless Humans Organized for Natural Genetics (THONG), October 6, 2004 http://www.zyvex.com/nanotech/feynman.html

  4. Why is Nanotechnology Important?

  5. Mercedes CLS-class Hummer H2 Wilson Double Core tennis balls Wyeth Rapamune immuno-suppressant 3M Adper Single Bond Plus dental adhesive Samsung Nano SilverSeal Refrigerator Laufen Gallery washbasin with Wondergliss Eddie Bauer Ruston Fit Nano-Care khakis Kodak EasyShare LS633 camera Smith & Nephew Acticoat 7 antimicrobial wound dressing NanoOpto subwavelength polarizing beam splitter/combiner What kinds of nanomaterials (nanoproducts) are currently in commercial production or use?

  6. Potential biomedical applications of some nanoparticles (adapted from G.L. Prasad, Biomedical Applications of Nanoparticles, Safety of Nanotechnology, 2009) Typical configurations utilized in nano-bio materials applied to medical or biological problems. Salata Journal of Nanobiotechnology 2004

  7. Appetite Control Bone Replacement Cancer Chemical Substitutes Cholesterol Diagnostic Tests Drug Development Hormone Therapy Imaging Immunosuppressant Medical Tools Over 20 already commercialized products Used by researchers involved in drug discovery Physicians in need of better imaging techniques Prescriptions to treat particular types of illness Current Medical Applications – Commercialized (FDA approved) http://www.nanotechproject.org/inventories/medicine/apps/

  8. Nanotechnology – new field and rapidly growing • 2007 world-wide public and private investment in nanotech >$13.9 billion1 • From 2001 through 2009 ~$10 billion in US funds in NNI • Estimated that by 2014 ~16% of global merchandise will contain nanomaterials or be manufactured using nanotechnology2 1www.nano.gov/PCAST_NNAP_NNI_Assessment_2008.pdf 2 www.oecd.org/dataoecd/37/19/37770473.pdf

  9. Nanotechnology Development - Opportunity and Unknown Risks • Opportunity goes hand in hand with risk • The global marketplace already has been challenged by a variety of risks posed by widely used materials • Risks carry with them the potential for far-reaching effects on market cycles, manufacturing, and the safety, security, and well-being of consumers • Nanotechnology adds an entirely new and largely unexplored realm of risks spread across the entire spectrum of modern commerce

  10. Nanotechnology Business Trends • “A technology without a product” – a ‘big’ product of many better products? • “Just one more tool available to us” – a decentralized approach • EHS issues remain the top challenge to commercialization • Looking to external innovators: Universities, government labs, and start ups • Nanotechnology needs to move out of the lab and into the marketplace Lux Research: Report on Nanotechnology Corporate Strategies 2008

  11. Business Driver for Better Understanding and Assessment of Nanotechnology EH&S Risks • In late 2008, Continental Western Insurance Group announced it would exclude nanotechnology and nanotubes from coverage • “Best-in-class risk assessment with proper controls, oversight, and documentation for this emerging area will be looked upon favorably by underwriters willing to insure nanotechnology risks.” Germano, C, Managing the Emerging Risks of Nanotechnology” The John Liner Review v22 No. 2 Summer 2008 • Swiss Re: “Only those who have a clear picture of the risk landscape can be reliable partners in the risk business itself.” Nanotechnology: Small matter, many unknowns, Swiss Re 2004 (www.SwissRe.com)

  12. EH&S Key Questions • Do these new nanomaterials present new safety and health hazards and risks? • Greater biological activity and mobility • Different exposure pathway(s) • How can the benefits of nanotechnology be realized while proactively minimizing the potential risk?

  13. Risk Analysis: Just as nanotechnology development is still in its infancy, so is the research into the potential risks • Possible Risks to Employees • Possible Risks to Consumers • Nanoparticles in the Outdoor Environment • Nanoparticles in the Food Chain • Unintended Consequences

  14. The three interconnected components of traditional Risk Analysis – risk assessment, risk management, and risk communication Risk management RISK ANALYSIS Risk assessment Hazard identification 1 Hazard characterization 2 Risk communication Exposure assessment 3 Risk characterization 4 European Commission Report 2004

  15. Traditional Risk Assessment: 4 Step process Risk Assessment Nanotoxicology What do we know? Are there trends? Hazard Identification Is there reason to believe this could be harmful? 1 How and under what conditions can it be harmful? Hazard Characterization 2 Exposure Assessment Will there be exposure in real world conditions? Exposure Can it be measured? Where is it Occurring? Metric? 3 Risk Hazard x Exposure Risk Characterization Is substance hazardous and will there be exposure? 4

  16. Nanoparticles Are Not a Recent Discovery Naturally occurring Engineered nanoparticles Man-made by-product

  17. Risk Assessment Step 1: Hazard Identification We already know a lot about pulmonary toxicity of some small particles and fibers in humans • Quartz • Related to surface area and surface activity • Asbestos • Particle length and diameter • Surface activity and durability • Air pollution • Medical applications

  18. Risk Assessment Step 2: Hazard Characterization But what is DIFFERENT about NANO-sized particles? • Total surface area is larger • Chemical reactivity is higher • Physical dimensions of the particle • Solubility • They may be more persistent (less biodegradable)? • Additional influence of exotic/unique properties? • Possible synergistic effects from composite materials and structures?

  19. Current Focus for the Workplace: unbounded engineered nanoscale particulate matter: nanoparticles • Not firmly attached to a surface • Not part of a bigger item (microchip, cell wall, composite material) • Can result in exposure via inhalation, skin absorption or ingestion

  20. Characterizing Hazard: Different Nanoparticle Types Merit Different Levels of Caution Weight Single-walled carbon nanotubes Multi-walled carbon nanotubes Nanoclay particles Cadmium-selenide quantum dots Zinc oxide nanoparticles Titanium dioxide nanoparticles Dendrimers Fullerenes Nanocrystalline drug formulations Silicon nanowires 35% Evidence of toxicity? Yes Nanoparticle more reactive than bulk? 15% Somewhat Bulk material toxic? 5% No Resists biodegradation? 10% Tends not to agglomerate? 5% High Readily purified and characterized? 10% Medium Evidence for specific bodily harm/mobility? 10% Low Evidence for environ- mental harm/mobility? 10% Potential hazard: Type of nanoparticle Characteristic Used with permission:. A Prudent Approach to Nanotech Environmental, Health and Safety Risks” Lux Research Inc 2005

  21. Risk assessment Step 3: Exposure assessment Royal Society Report July 2004

  22. Where will earliest exposure occur? Potential contact with unbounded nanoparticles peaks in production or use Least is known about material To Be Determined Occupational Non-Occupational

  23. Nanoparticles Have Almost No Mass Edge of a single 10 micron particle Relative size of 10 nanometer particles for comparison A 10 mm particle weighs the same asone billion 10 nm particles Large particles will bias filter weight

  24. Standard 37mm filter cassette 3. Exposure Assessment: Sampling for Nanoparticles Large Particles Bias Mass Measurements (Filter) “If you’re carrying a grocery bag full of cantaloupes, you’re not going to notice a handful of grapes”

  25. Condensation Particle Counter: Principle of Operation • Advantages: • Real-time output • Portable • Relatively inexpensive • Disadvantages: • Not-size resolved • Non-specific detection Airflow Saturator 40 ºC Alcohol-soaked wick Condenser 10 ºC Optics Number concentration dp < 1 µm Airflow Exit

  26. Condensation Particle Counters (CPCs) Courtesy of TSI Courtesy of TSI Courtesy of GRIMM Courtesy of TSI

  27. + + A Diffusion Charger: Principle of Operation Faraday Cup • # of ions attached ~ particle surface area + + + + + + + + + + Ion source + + + Current meter + +

  28. Surface Area Measurement: Diffusion Chargers Courtesy of EcoChem Courtesy of TSI • Advantages: • Real-time output • Portable • Surface area may be relevant to health hazards • Disadvantages: • Not-size resolved • Non-specific detection • Susceptible to bias from large particles (> 100 nm)

  29. Mass and Size MOUDI – Micro-Orifice, Uniform Deposit Impactor Range of 56 nm to 18 um in 10 stages Mass and elemental analysis

  30. Number and Size Scanning Mobility Particle Sizer (SMPS) This is a combination particle classifier and detector that provides real time size distribution. The SMPS system measures particles from 2.5 to 1000 nm and display data using up to 167 actual size channels

  31. Summary of Nanoparticle Measurement Techniques 1 µm 1 nm 10 nm 100 nm 1000 nm Increasing $$ Passive sampler and microscopy CPCs Diffusion charger Low Pressure Impactors Scanning Mobility Particle Sizer Number based Surface Area based Mass based

  32. Risk Assessment Step 3: Assessment of Exposure to Nanoparticles • We can measure nanoparticle concentrations in real-time (CPC, diffusion charger, cascade impactor) • Non-specific for particle material • Not size-resolved • Lower size limitations (10 – 20 nm limits) • To date, only research-grade equipment can measure size-resolved nanoparticles in real-time: • Scanning Mobility Particle Sizers (SMPS) • Particle non-specific

  33. Exposure Assessment: The problem of specificity • Concentration data does not provide information on particle composition • Not only do we need to be able to detect nanoparticles, we need to be able to identify their source. • Also need to measure personal exposures to nanoparticles

  34. To assess risk, a Life Cycle Approach is needed Knowledge of Hazard Needed to assess Risk Research Laboratories Low Start Up/Scale Up Operations Manufacturing/Production Incorporation in Products High Consumer/Environmental Use ??? End of Life/Disposal ??? Recycle Adapted from Geraci, NIOSH 2009

  35. Life Cycle Risk Assessment: Variation on Theme • Nano Risk Framework (EDF/Dupont 2007) • Nano-LCRA (Shatkin 2008) • Comprehensive Environmental Assessment (Davis, 2007)

  36. Risk assessment Step 4: Risk characterization Matching hazard to applications • Combining hazard characterization with exposure assessments • Risk calculations • Susceptibility • Extrapolation models • (high-low) • (animal-human_ • Value of mechanistic data from in vitro studies

  37. Cautions for Reading nano Reports • Consider original sources • Look for appropriate qualifiers • Look for issues of scale • Ensure exposures were to nano-size particles and individual nanomaterials • Do not generalize form one study to another • Don’t assume that experimental results can be extended to actual biological systems or the environment • Probe possible other reasons for toxicity • Don’t assume common sense macroscopic physics holds at the nanoscale T. Bell, “Understanding Risk Assessment of Nanotechnology” 2006 http://www.nano.gov/Understanding_Risk_Assessment.pdf

  38. The three interconnected components of traditional Risk Analysis – risk assessment, risk management, and risk communication Risk management RISK ANALYSIS Risk assessment Hazard identification 1 Hazard characterization 2 Risk communication Exposure assessment 3 Risk characterization 4 European Commission Report 2004

  39. Risk Management Assessing and Controlling Risk To control risk, it is the responsibility of the nanotechnology professional to understand the potential hazards of the materials and processes involved by: • Identifying Hazard • Reducing hazardous properties • Substitute less hazardous substance for more hazardous where possible • Reducing probability of exposure • Engineering and procedural controls to limit worker exposure • Limit release of material to environment • Interrupt pathways to a receptor

  40. Exposure Exposure Exposure routes Exposure routes Characterization Characterization Dose Dose Risk Risk Control Control Reduced risk/impact Reduced risk/impact Health Effects Health Effects Knowledge Level Poor Good Toxicity Toxicity Risk assessment/control map with knowledge levels of variable risk areas NIOSH: Maynard, 2005

  41. Risk Perception: An additional component to the traditional risk analysis model Risk perception Risk management RISK ANALYSIS Risk assessment Hazard identification 1 Hazard characterization 2 Risk communication Exposure assessment 3 Risk characterization 4

  42. More Nanotechnology Revenue is Exposed to Perceptual Risk than Any Other Class of Risk Used with permission:. A Prudent Approach to Nanotech Environmental, Health and Safety Risks” Lux Research Inc 2005

  43. Nanotechnology Risk Communication Challenges • Public attitudes towards technological risks • Public perceptions • Media • Trust E. Schuler, Rice University, Texas “A prospective look at Risk Communication in the Nanotechnology Field.” 2004

  44. Perception and Regulations • Lack of sufficient risk information • Technology has outpaced government regulation • Companies develop own principles and procedures

  45. Nanotechnology Regulatory Landscape – U.S. EPA • EPA is very “plugged in” both internationally (e.g. ISO; OECD) and domestically (e.g. California DTSC activities) • EPA Nanotechnology White Paper • http://www.epa.gov/OSA/pdfs/nanotech/epa-nanotechnology-whitepaper-0207.pdf • Two basic, primary authorities: TSCA & FIFRA (plus more…) • http://www.epa.gov/oppt/nano/ • http://www.epa.gov/pesticides/about/intheworks/nanotechnology.htm

  46. California: Newly-Enacted Green Chemistry Legislation • In September 2008, California adopted first-in-the-nation Green Chemistry legislation, described by Governor Schwarzenegger as leading to “comprehensive” regulations to “reduce or eliminate” hazardous chemical “in our products” and the environment. • By January 2011, DTSC must adopt regulations designed to (1) identify and prioritize chemicals in consumer products considered “chemicals of concern,” (2) identify potential hazards and alternative to such chemicals, (3) develop “multimedia lifecycle evaluation”, and (4) propose appropriate chemical-specific regulations to prevent adverse effects.

  47. Highlights of January 2009 California Department of Toxic Substances Control (DTSC) CNT “Call-In” Letter • Sent by DTSC to 26 companies and universities thought to be “manufactures” of carbon nanotubes (CNTs). • “Manufacturers” include “persons . . . that produce carbon nanotubes in California or import carbon nanotubes into California for resale.” Agency specifically indicated this applies to universities. • Potential application to others that are identified through call-in • Exercises mandatory authority under Cal. H&S Code to require recipients to provide “any or all information, with supporting references,” concerning six specific questions within 365 days.

  48. January 2009 DTSC Letter Poses Six Questions for “Initial Phase” of Data Call-In for carbon nanotube users • What is the value chain for the company? • What sampling, detection and measurement methods are you using to monitor (detect and measure) the presence of your chemical in the workplace and the environment? • What is your knowledge about the current and projected presence of your chemical in the environment that results from manufacturing, distribution, use, and end-of-life disposal? • What is your knowledge about the safety of your chemical in terms of occupational safety, public health, and the environment? • What methods are you using to protect workers in the research, development and manufacturing environment? • When released, does your material constitute a hazardous waste under California Health & Safety Code provisions?

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