nanotechnology, industrial hygiene, and the electric power industry s/eeifall2014/ih/webb.pdf ·...
TRANSCRIPT
Nanotechnology, Industrial Hygiene, and the Electric Power Industry
Paul J. Webb, CIH, CSP Colden Corporation
The Promise of Nanotechnology
“Nanotechnology will leave virtually no aspect of life untouched and is expected to be in widespread
use by 2020.”
- ASME.org
Source:
Top 5 Trends in Nanotechnology, by Nancy S. Giges, ASME.org
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 4
The Promise of Nanotechnology
Follow the money: 2015 U.S. Federal Budget provides more than $1.5
billion for the National Nanotechnology Initiative (NNI)
Global market for nanotechnology estimated to reach $3.3 Trillion by 2018
Sources: National Nanotechnology Initiative: http://nano.gov/ PRNewswire-iReach, December 3, 2012 Nano, IH, and the Electric Power Industry, Fall 2014 Conference 5
Advantages of Nano-scale Materials
Altering materials at a molecular level, creates materials that tend to be lighter, stronger, and more reactive than materials made with larger
size particles of the same material
This all sounds fantastic but…. Is this technology creating something that could end up being harmful to us, and/or the environment?
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 6
The Potential Risks
Title from a recent article in Forbes.com:
Doctors Claim New Evidence That Nanotechnology Can Make Workers Sick
by Robert Bowman, Forbes.com
Source:
http://www.forbes.com/sites/robertbowman/2014/08/14/doctors-claim-evidence-that-nanotechnology-can-make-workers-sick/
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 7
The Potential Risks
Litigation - NRDC sues EPA over allowing the use of nanosilver:
NRDC says no to nanosilver March 1, 2012 / Advanced Textiles Source / In the Industry
“Nanosilver penetrates organs and tissues in the body that larger forms of silver cannot reach, like the brain, lung and testes.”
“Nanosilver has potentially devastating effects when released into the environment and potentially damaging effects when
absorbed by humans.”
- Dr. Jennifer Sass, senior scientist, NRDC health program
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 8
Nanotechnology Current Themes, good and bad (maybe)
Lots of optimism about the future of nanotechnology
Although relatively new, nanomaterials are already widely used in the workplace and our society
Also some concerns:
Speculation about possible long-term health consequences
including comparisons with asbestos
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 9
Topics for Discussion
Introduction to Nanotechnology
Relevance to Health and Safety
Nanotechnology and the Electric Power Industry
Exposure Assessment Considerations
Evaluation Techniques
Summary and Additional Resources
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 10
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 11
Introduction to Nanotechnology
Nanotechnology
Nanotechnology is a cross-disciplinary field that involves the creation and application of novel materials, devices and systems by control and restructuring of matter at dimensions of roughly 1 – 100 nanometers in size
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 12
Nanomaterials
Structures greater than atomic/ molecular dimensions but less than 100 nanometers
Structures that exhibits physical, chemical and/or biological characteristics associated with its nanostructure
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 13
Nanomaterials
Nanomaterials is a term that includes all nano-sized materials including:
Engineered nanoparticles
Ultrafine particles: Incidental nanoparticles (formed as a by-product)
Welding fumes, fossil fuel combustion
Any nano-objects that exist in nature (sea spray or particles formed through erosion)
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 14
Nanoparticles
A nanoparticle:
Is a nano-scale material (nanomaterial)
Can be described by its shape and size
May have unique physical, chemical or biological properties
May be heterogeneous, consisting of a core, and outer shell or coating
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 15
Nanoparticles are Tiny
Compared to a diameter of 100 nanometers :
is
Beach sand , 90 micrometers (µm) in diameter
900 times larger
Human hair, 50-70 µm in diameter
500 times larger
Dust, pollen, and mold, < 10 µm in diameter
100 times larger
Red blood cell, 7.5 µm in diameter
75 times larger
Combustion products, <2.5 µm in diameter
25 times larger
Red Blood Cell
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 16
Engineering Nanomaterials (ENMs)
Engineered Nano-Scale Materials (ENMs) include: carbon nanotubes, fullerenes, titanium dioxide (TiO2), carbon black, cobalt oxide (Co3O4), and nickel (Ni)
ENMs present a significant exposure potential since they can readily enter the body
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 17
Other Types of Nanoparticles (Ultrafine Particles)
Ultrafine particles are:
Defined as those less than 100 nm and qualify as nano-sized particles
Not purposefully manufactured and vary in composition and size
The result of combustion or friction processes or natural processes in the air or water
Source: EPA
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 18
Relevance to Health and Safety
For ENMs:
EHS practice will increasingly require a working knowledge of their health risk
As awareness grows, all stakeholders will want to know their risks from ENMs
For Ultrafine Particles:
Traditional exposure assessment may not adequately define hazard
A different approach is necessary
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 19
Toxicity of Nanoparticles
Key issue – composition vs. size
• Example: carbon
Large particles – e.g., carbon black - relatively nontoxic
Nano-scale size particle (e.g., carbon nanotubes, fullerenes) – toxicity is unknown
Even more so for functionalized nanoparticles
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 20
Smaller Size, Larger Numbers
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 21
Source: Biswas and Wu (2005)
Toxicity: Key Points
Surface area and particle number become much more important as the particles become smaller, compared to mass
For toxicological end points, mass may be a less important exposure metric than exposure metrics that depend on surface area or number
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 22
Dermal Exposure
Nanoparticles may act more like a gas than a particle
Normal intact skin appears to provide a barrier for many nanoparticles, although the risk of entry increases for flexed or abraded skin
Gloves and other protective equipment may not offer adequate protection
Dermal contact may serve as a route of entry for certain nanoparticles
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 23
Particle Mobility (Once in the body)
As particles reach the nanometer size range, they may become more biologically mobile:
Cross cellular boundaries from the alveolar region into the circulatory system
Pass through the skin
Travel through the olfactory nerve to the brain
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 24
Toxicity Observations
1. Factors: Surface area, chemical composition, particle number and surface reactivity (free radical)
2. Nano-size particles cause greater adverse inflammatory response
3. Carbon nanotubes induce dose-dependent lung inflammation
4. Can go through cell membrane into circulatory system and translocate to other organs (brain, kidney, CNS). Persistence in neuronal tissue is unknown
5. Dermal penetration may be a route of entry for some nanoparticles
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 25
Carbon Nanotube (CNT) Toxicity
Many studies published in the recent years have focused on CNT toxicity
End point studied:
Fibrosis
Inflammation of lung and cardiac tissue
Mesothelioma
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 26
Do CNTs Cause Mesothelioma?
Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study,
Source: Poland et al., Nature Nano., 2008
Induction of mesothelioma in mouse by intra-peritoneal application of multi-wall carbon nanotube,
Source: Takagi, et al.,J. Toxicol. Sci, 2008
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 27
Do CNTs Cause Mesothelioma?
“Here we show that exposing the mesothelial lining of the body
cavity of mice, as a surrogate for the mesothelial lining of the chest cavity, to long multi-walled carbon nanotubes results in asbestos-like, length-dependent, pathogenic behaviour… Our results suggest the need for further research and great caution before introducing such products into the market if long-term
harm is to be avoided.” Source: Poland et al., Nature Nano., 2008
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 28
Nanotechnology and the Electric Power Industry
Sustainability Applications
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 29
Sustainability
Sustainability is a major trend affecting investment decisions within the electric power industry
The effects are already evident in increased funding of alternative energy sources and reduction targets in CO2 emissions
Nanotechnology is being applied across the value chain to improve power generation, delivery, and storage efficiencies
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 30
Key Benefits to the Electric Power Industry
Nanostructured materials are designed to be superior to conventional materials in the following ways:
Stronger and lighter
Different magnetic properties that can be controlled
Better di-electric properties
Better conductors of heat or electricity
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 31
Relevance to Electric Power
Advanced nano-engineered materials increase efficiencies in:
Electricity Generation
Electrical Transmission and Distribution
Electrical Energy Storage
Reference: 2014 Outlook on Power & Utilities My take: By John McCue, Deloitte LLP
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 32
Electricity Generation
Polymer nano-composites: addition of nanomaterial improves di-electric qualities and strength
Nano-lubricants: improves efficiency by reducing friction coefficients for conventional power generation turbines
Evolving nanotechnologies are expected to find applications in all parts of the industry
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 33
Electricity T&D
Highly conductive carbon nanotubes can substantially cut energy loss from transmission lines
System Diagnostics: nano-sensors will help utilities
detect operations issues in advance by monitoring current and voltage along the grid, detecting the condition of underground cables, and evaluating transformers and other equipment
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 34
Electricity Storage
Supercapacitors have fast charge and discharge capabilities over hundreds of thousands of cycles, and are used in electrical storage in power grid applications
Nanomaterials and nanostructured surfaces improve energy
storage capacity by controlling charge transfer processes in these materials
Nano-infused electrodes use materials like carbon nanotubes to produce supercapacitors
Benefits include lighter and more powerful batteries and
capacitors
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 35
Product Development Areas
Nano-designed dielectrics: engineered to an exact specification results in improved response to
changing electric fields Electrical equipment applications: cables, bushings, surge arresters and
insulating materials
Nano-structured sliding bearing (in development):
Electrical equipment applications: switchgear operation without oil Lower operating costs and less environmental impact
Source: ABB Research and Development http://www.abb.com/cawp/seitp202/d0384d7076c42f3ec1256eef0040a58a.aspx
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 36
Exposure Assessment Considerations
Challenges
Measurement options
Combining methods
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 37
Exposure Assessment Challenges
1. Exposure Levels at which particles produce adverse health effects are generally known whereas there is limited toxicological data and OELs for nanoparticles
2. Sampling and Analytical methods include
microscopic and mass-based measurement of known materials. Analysis of ultrafine particles relies on non-specific direct reading measurement
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 38
Exposure Assessment Challenges
3. Nanoparticle behavior: Nanoparticles behave differently than larger particles based on their unique size, shape and densities
4. Exposure Metrics: Debate continues over
what is the most appropriate method to measure exposure:
Total surface area? Mass concentration? Number concentration?
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 39
Exposure Assessment Challenges
5. Interpretation of results: Real-time
instruments can measure nanoparticles, but most have significant biases and are not specific to the particle of interest (e.g., condensation particle counters, surface area monitors, etc.)
Example: using a particle counter to measure welding fumes, but the work occurs in an area with other sources of nanoparticles
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 40
Nanoparticle Measurement Options
Screening for nanoparticles
Particle counters and simple size analyzers
Specific Characterization
Filter-based samples for electron microscopy and elemental analysis
Collected at the source and at personal breathing zone
Use of less portable aerosol sizing equipment
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 41
Combining Methods
One option is to combine analytical and sampling methods using a combination of lab-based protocols along with the use of direct reading instruments
For ultrafine particles (non-ENMs), the use of direct reading instruments (DRIs) can provide a quick measure of workplace conditions
Example: particle size distribution for welding fumes are most abundant in the range of 0.1 – 2.5 µm
Source: Sowards et al (2008)
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 42
Direct Reading Instruments (DRIs)
Advantages
Real-time feedback of airborne particle behavior
Helpful for evaluating equipment operation and short-term tasks, lasting seconds to minutes
Disadvantages/Pitfalls
Non-specific, measure all particles present and that are within the operational range of the equipment
All potential interferences must be identified in order to properly interpret the results
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 43
Optical Particle Counters and Photometers
Optical particle counters (OPCs) measure particle size and number concentration by detecting the light scattered from individual particles
Photometers use conventional light-scattering technology to closely estimate particulate mass concentrations (mg/m3)
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 44
Condensation Particle Counter (CPC)
Condensation particle counters first enlarge very small particles to an optically detectable size
Concentration measured in particles per cubic centimeter air (particles/cm3)
They are used to count particles in size ranges that are invisible to OPCs and photometers
Good choice for measurement of ultrafine particles
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 45
DRIs - Photometer
Measures aerosol concentrations corresponding to PM1, PM2.5, Respirable, or PM10 size fractions
Aerosol concentration range 0.001 to 150 mg/m3
Manual and programmable data logging functions
DustTrak™ II Aerosol Monitor 8532 Photometer
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 46
DRIs – CPCs
Particle size range of 0.01 to >1.0 µm
Concentration range of 0 to 100,000 particles/cm3
Battery-powered operation
Programmable data-logging capabilities
TSI Model 3007
Condensation Particle Counter (CPC)
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 47
Comparison of CPC and OPC ranges
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 48
1.0 nm 10 nm 100 nm 300 nm 1.0 µm 10 µ
CPC OPC
• OPC and CPC share the same size range between ~300 nn and 1.0 µm
• The NIOSH NEAT Method describes how both DRIs can be used together to determine number concentrations of smaller versus larger sized particles
NIOSH REL = 1 μg/m3 Analytical Method: NIOSH Method 5040, Total Elemental Carbon
Mass Concentration Analysis
Issued: April, 2013
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 49
Filter-Based Microscopic Analysis
Tubular/Fibrous: • High Aspect Ratio
(e.g., Carbon Nanotubes) Irregular Shapes:
• Generally More Surface Area
Than Compact Particles (e.g., Iron Powders)
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 50
Evaluation Techniques
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 51
Example: Welding fume evaluation protocol Combining laboratory-based analysis and DRIs to develop an exposure metric for welding fumes
Welding Fumes: Key Points
Welding fumes are classified as ultrafine particles
Traditional filter sampling based on mass does not adequately define health risk
Fume particles are present in higher concentrations than smaller particles and are most abundant in the range of 0.1 to 2.5 micrometers (Sowards et al, 2008)
DRIs, such as CPCs, can be used to assess exposure during short tasks and effectiveness of controls
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 52
Evaluation Protocol: Welding Fumes
Identify all sources of ultrafine particles prior to sampling
Collect baseline sampling using desired DRI
Identify all sources of ventilation: local exhaust, and other natural/mechanical sources
Identify all hot work consumables and metal surfaces to be welded
Do side-by-side filter/elemental sampling along with DRI sampling
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 53
Evaluation Protocol: Welding Fumes
When sampling using a DRI, identify specific locations where sampling will occur, describing the distance from the source and worker.
Spot-sample at the welder’s breathing zone, under the welding helmet and outside of helmet. Do not sample under the respirator if one is being worn
Filter cassette should be placed inside welding helmet per OSHA Technical Manual: if respirator used (i.e.: hooded PAPR) collect outside respirator device
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 54
Evaluation Protocol: Welding Fumes
Review lab results, DRI welding and background DRI levels
Compare background levels with DRI concentrations collected during task (During task/Background) = DRI factor
Compare lab results with OEL (Level during task/OEL) = hazard factor
Correlate hazard factor with DRI factor
Goal: To be able to use DRI data alone to predict risk
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 55
Evaluation Protocol: Welding Fumes
Risk Level Matrix
If there is good correlation between hazard and DRI factors, a risk level matrix can be established
Consider defining risk as either low, medium, or high based on the hazard factor and corresponding DRI factor as follows:
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 56
Risk Level Hazard Factor DRI Factor*
Low ≤ 0.20 20x or less
Medium 0.20 – 0.40 20x - 30x
High >0.40 >30x
*These values can be adjusted based on field data results and professional judgment
Evaluation Protocol: Welding Fumes
• Assume stainless steel welding, hexavalent chromium, PEL = 5 µg/m3 and Background DRI = 10 µg/m3
• Risk Level could be assigned low, medium, or high, based on correlation with hazard factor
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 57
Lab result (µg/m3)
Hazard Factor
DRI data (µg/m3)
DRI Factor
Risk Level
1 0.20 100 10 Low
3 0.60 300 30 Medium
5 1.00 500 50 High
7 1.40 700 70 High
Note: All values in table are hypothetical
Summary and Conclusions
Implications
References
Resources
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 58
Implications
The promise of nanomaterials has similar parallels that were associated with the rise of asbestos in the first part of the 19th Century
The use of nanomaterials is rapidly increasing
Neither the occupational nor the non-occupational exposure risk is well understood
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 59
Implications
Actual or perceived risk from nanomaterials poses a potential litigation risk to organizations that are involved at all stages of the value chain, from R&D to end users
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 60
References
Giges, Nancy S. (2013): Top 5 Trends in Nanotechnology, ASME.org
Bowman, Robert (2014): Doctors Claim New Evidence That
Nanotechnology Can Make Workers Sick, Forbes.com
McCue, John (2013): My take: 2014 Outlook on Power & Utilities, Deloitte LLP
Sowards, J. W. et al (2008): Characterization of Welding Fume from
SMAW Electrodes - Part I. Welding Research, April 2008, Vol. 87, pp. 106-112.
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 61
Industrial Hygiene Resources Nanotechnology Health and Safety
Good NanoGuide, http://www.goodnanoguide.org/HomePage
Dimitri, J., Rickabaugh, K., Webb, P., Shepard, M. Industrial Hygiene Practices for Assessing Nanomaterials Exposures (Nov, 2013), AIHA The Synergist, AIHA, pp24-27
Join the AIHA Nanotechnology Working Group
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 62
63
AIHA Nanotechnology Working Group (NTWG)
2014-2015 Leadership Team Chair – Jennifer Dimitri Vice Chair – Michele Shepard Secretary – Paul Webb Secretary-Elect – John Baker Past Chair – Candace Tsai AIHA Liaison– Thursa L. Pecoraro, [email protected]
Visit our webpage under Volunteer Groups @AIHA: www.aiha.org/insideaiha/volunteergroups/Pages/NTWG.aspx
Nano, IH, and the Electric Power Industry, Fall 2014 Conference
Questions?
For further information regarding this presentation, health risk assessments, or litigation support, contact:
Colden Corporation
Occupational and Environmental Health Science Group www.colden.com
Shannon Magari, ScD, MS, MPH
Paul J. Webb, MPH, MBA, CIH, CSP
Nano, IH, and the Electric Power Industry, Fall 2014 Conference 64