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Overview of Nanotechnology: 

Risks, Initiatives and Standardization

 

By

Jolinda Cappello

 

 

Table of Contents

Introduction

What is Nanotechnology?

Products and Applications

Health and Safety Risks of Nanoparticles

A. Nanoparticles and the Human Body

B. Nanoparticles in the Workplace

1. Effects of Nanoparticle Exposure

a. Respiratory Exposure

b. Exposure Through Ingestion

c. Dermal Exposure

2. Effects of Environmental Exposure

What Can Be Done to Protect Workers?

A. Current Initiatives

B. Suggested Initiatives

Current Efforts Toward

Nanotechnology Standardization

A. ANSI Nanotechnology Standards Panel

B. ASTM International

Conclusion

Works and Websites Consulted

Introduction

Many believe that nanotechnology will be the next industrial revolution and the key to a future filled with new opportunities and applications. In recent years, nanotechnology’s possibilities have received global attention, and worldwide government investment in nanotechnology has increased greatly since the mid-1990s.

The information in this paper is adapted from recent print and online resources to provide an overview of:

 

·        Nanotechnology and its products and applications

·        The health and safety risks of nanoparticle exposure in the workplace

·        Current and suggested initiatives and activities to protect workers in nanotechnology industries

·        Current efforts toward nanotechnology standardization

What is Nanotechnology?

Nanotechnology is often considered engineering at the atomic scale. A nanometer is one billionth of a meter, and the term “nanotechnology” refers to engineered structures, devices and systems that have a length scale of 1-100 nanometers. At these length scales, materials begin to exhibit distinct properties that affect their physical, chemical and biological behavior.

The nanometer length scale is unique because it makes it possible to change the fundamental properties of materials without altering their chemical composition. Particles at the nanoscale, or nanoparticles, have very high surface areas, and their behavior and mobility can be changed. This creates unlimited possibilities for products and applications.

Numerous existing technologies depend greatly on processes that take place on the nanometer scale. Important nanomaterials used commercially include:

·        Carbon tubes

·        Titanium dioxide

·        Silicon/germanium

·        Calcium oxide-based materials

·        Metal-cored coated particles

·        Proteins or DNA

Nanotechnology allows scientists to specifically analyze, organize and control matter on many length scales simultaneously.

Products and Applications

Nanotechnology is divided into the following three approaches, which in turn give way to specific products and applications:

Top-Down—A given bulk material is reduced in size to produce nanometer-scale particles, which are then either systematically inserted into larger structures or used as an admixture to other materials.

Bottom-Up—Larger structures are built up atom by atom or molecule by molecule or are allowed to grow through self-assembly.

Self-Assembly—Components spontaneously assemble, usually by moving in a solution or gas phase, until a stable structure of minimum energy is reached. A living cell is the most successful “nanofactory” known to humankind.

Nanoparticles are currently used in the electronic, magnetic, optoeletronic, biomedical, pharmaceutical, cosmetic, energy, catalytic and materials industries. Areas that produce the greatest revenue for nanoparticles include chemical-mechanical polishing, magnetic recording tapes, sunscreens, automotive catalyst supports, biolabeling, electroconductive coatings and optical fibers.

Nanoparticles are also used in the medical field to aid in drug delivery and medical imaging, and it is predicted that nanotechnology will contribute to new cancer therapies, new treatments for infections and brain diseases and new drugs with fewer side effects.

Advanced nanotechnology, or that which works with artificial intelligence, nanorobots and self-assembly, is expected to increase significantly.

Nanotechnology is also expected to play a major role in environmental protection. Nanoparticles may be used in contaminant neutralization, magnetic techniques, special filtering and cleaning methods, environmental decontamination, energy conservation and in the production of energy-efficient devices.

Health and Safety Risks of Nanoparticles

Although nanotechnology’s infinite potential is encouraging, the health and safety risks of nanoparticles have not been fully explored. The omnipresence of nanoparticles is not a threat, but it is critical to weigh the opportunities and risks of nanotechnology in products and applications that involve human contact or that may affect the environment.

As particles decrease in size, the more reactive they become. As reactivity increases, so may the harmful effects of a substance. Therefore, nanotechnology can make normally harmless substances assume hazardous characteristics. Nanoparticles’ large relative surface area also enables them to exert a stronger effect on their environment and to react with other substances.

A. Nanoparticles and the Human Body

It is known that nanoparticles can enter the human body by:

·        The bloodstream by inhalation through the lungs

·        The digestive tract

·        The blood-brain barrier

Evidence also shows that nanoparticles may be able to enter the body through the skin. However, in order to learn how these nanoparticles behave in the human body, studies must be carried out on test individuals, and at this point in nanotechnology development, that is an unrealistic prospect.

B. Nanoparticles in the Workplace

Nanotechnology presents many workplace health and safety concerns. More than two million U.S. workers are exposed to nanoparticles on a regular basis, and that figure is expected to double as nanotechnology-related industries increase worldwide. This raises fears that the growth of nanotechnology may outpace the development of appropriate safety precautions.

Several monitoring and protective strategies are already in place to safeguard U.S. workers, but experts believe that more research is needed to determine the effects of nanoparticle exposure.

Existing toxicology studies from known ultrafine particles and incidental nanoparticles give some clues as to how manufactured nanoparticles might behave. However, their behavior and other attributes must be characterized to see if they have different toxicological effects.

Since the occupational health risks associated with manufacturing and the use of nanomaterials are not completely understood and since no one can predict the future of nanotechnology, it is imperative for the industry to take action now to assess the risks involved.

1. Effects of Nanoparticle Exposure

Nanoparticle exposure during manufacturing and use may occur through:

·        Inhalation

·        Ingestion

·        Dermal contact

Minimal information is available on dominant exposure routes, potential exposure levels and material toxicity. Existing information comes primarily from the study of ultrafine particles.

a. Respiratory Exposure

Ultrafine particles are proven to be ten to 50 times more damaging to lung tissue than other particles. Pollution from power plants, incinerators, cement kilns and diesel engines all contain ultrafine airborne particles that contribute to thousands of pollution-related deaths each year. Ultrafine particle exposure may cause lung inflammation, lung fibrosis, asthma, breathing problems and possibly even Alzheimer’s disease.

The level of damage these ultrafine particles cause to lung tissue and how deeply they penetrate the lungs depends on their size. Studies show that smaller particles cause a stronger reaction in lung tissue, as surface reactivity can harm the surrounding tissue through chemical activity. Even large particles that normally do not cause damage to lung tissue can cause damage when they are crushed to nanoscale.

Most inhaled particles are exhaled, but particles that penetrate the lungs more deeply, such as nanoparticles, enter into the pulmonary alveoli. Cells called phagocytes are responsible for absorbing foreign substances in the lungs and eliminating them, but if phagocytes absorb nanoparticles, a large amount of nanoparticles could be deposited in the lung tissue without being exhaled again. As the pulmonary alveoli exchange oxygen with blood, the nanoparticles could enter the bloodstream and be absorbed by blood cells. Some believe that the inhalation of carbon nanotubes, a specific type of nanoparticle, may cause illness similar to asbestosis because the nanotubes resemble asbestos fibers in shape.

Studies have also shown that when inhaled, some nanoparticles can enter directly into the brain through the nasal mucous membrane, thus bypassing the blood-brain barrier.

b. Exposure Through Ingestion

Nanoparticles may be ingested through drinking water, food additives, atmospheric dust on food, toothpaste and dental fillings and implants. Ingested nanoparticles can then be absorbed through “Peyer’s Plaques” or small nodules in intestinal tissue that are part of the immune defense system. If nanoparticles enter the digestive system and proceed into the bloodstream, they could move throughout the body and cause damage.

Nanoparticles may also accumulate in certain organs, disrupt and impair biological, structural and metabolic processes and weaken the immune system.

c. Dermal Exposure

It is possible that nanoparticles can penetrate the skin and be absorbed into the bloodstream, but further research is needed to determine if this is true.

2. Effects of Environmental Exposure

Many of the nanoparticles that occur in nature are soluble in water, but scientists claim that manufactured nanoparticles could adversely affect the environment.

Nanoparticles tend to agglomerate and change into larger microparticles, which are less reactive, less mobile and less well-distributed. To prevent agglomeration, manufacturers will often coat commercially available nanoparticles. This makes them reactive and highly mobile in the environment.

If these nanoparticles are released into the water or air, they could contaminate soil and groundwater. Pollutants could spread globally if these nanoparticles enter into the water cycle. If plant roots were to absorb nanoparticles, the human and animal food chain could become contaminated through crop consumption.

Artificially manufactured nanoparticles used in disposal items could also contaminate soil and groundwater if they are not properly recycled or removed as waste.

What Can Be Done to Protect Workers?

Since workers within nanotechnology-related industries have the potential to be exposed to uniquely engineered materials at levels far exceeding ambient concentrations, it is critical to confirm the health and safety effects of nanoparticle exposure and to establish standards and regulations for the nanotechnology workplace.

A.     Current Initiatives

1.      Researchers continue to investigate how nanoparticles affect biological processes that may lead to specific health effects.

2.      The National Institute for Occupational Safety and Health’s (NIOSH) Nanotechnology and Health & Safety Research Program is a five-year multidisciplinary study that explores a range of toxicity and health risks associated with workplace nanoparticle exposure.

3.      The National Toxicology Program of the U.S. Department of Health and Human Services has several nanotechnology studies in progress.

4.      Industry specialists are conducting research in the following areas:

·        Carbon nanotubes

·        Monitoring nanoparticle exposures with respect to aerosol surface area concentration

·        Risk assessment for nanoparticle exposure

·        Bypass leakage and nanoparticle recirculation in the workplace

·        Surface activity of inhaled particles

·        Evaluation of occupational nanoparticle exposures

·        Characterization and control of beryllium ultrafine aerosols

·        Characterization of metallic nanoparticles from diesel combustion

·        Ultrafine particle intervention in automotive plants

B. Suggested Initiatives

1.      Protective measures should be taken in conjunction with a continuing program of risk analysis.

2.      The insurance industry should evaluate and calculate the risks associated with nanotechnology.

3.      Safety, health and environmental (SH&E) professionals in existing or potential nanotechnology industries should begin to develop their health and safety strategies.

4.      Workers in nanotechnology industries should be made aware of the confirmed and potential health effects of nanoparticle exposure.

Although it will be some time before nanotechnology regulations are firmly established, steps must be taken now to reduce nanoparticle exposure in the workplace and to ensure that workers are adequately protected.

Current Efforts Toward Nanotechnology Standardization

The American National Standards Institute (ANSI) and ASTM International have both created groups that are responsible for developing nanotechnology standards. Each organization’s purpose and standardization goals are outlined below.

A. ANSI Nanotechnology Standards Panel

ANSI established the ANSI Nanotechnology Standards Panel (NSP) at the request of the Office of Science and Technology Policy (OSTP) of the Executive Office of the President of the United States.

The purpose of the ANSI-NSP is to serve as the cross-sector coordinating body for developing standards including nomenclature/terminology, materials properties, testing, measurement and characterization procedures in nanotechnology. The ANSI-NSP will provide the framework within which stakeholders can work cooperatively to promote, accelerate and coordinate the timely development of voluntary consensus standards that are intended to meet identified needs related to nanotechnology research, development and commercialization.

The panel plans to:

1.      Coordinate and provide a forum to define needs, determine work plans and establish priorities for updating standards or creating new standards.

2.      Solicit participation from nanotechnology-related sectors and academia that have not traditionally participated in the voluntary standards system and work cooperatively to achieve the ANSI-NSP’s mission.

3.      Facilitate the timely development and adoption of standards that are responsive to identified needs in nanotechnology in general and to nomenclature/terminology specifically.

4.      Facilitate collaborative efforts among standards-developing organizations to establish work plans and to develop joint and/or complementary standards.

5.      Obtain agreements from standards developers to initiate the development standards in a timely manner.

6.      Establish and maintain liaisons with other national, regional and international standards efforts that address nanotechnology issues so as to create identical standards or to harmonize existing standards.

7.      Establish and maintain an online database of nanotechnology standards that is capable of generating updates, notices and reports.

8.      Identify any impediments that prevent the timely adoption of needed American National Standards.

9.      Make widely available the results of the ANSI-NSP’s work.

ANSI-NSP also released a series of recommendations that provide a broad framework from which nanotechnology standards can be approached.

The recommendations identify the following four standardization topics, which are to be addressed within a one-year timeframe:

·        General terminology for nanoscience and technology, including the definition of the term “nano,” the impact on intellectual property and sensitivity to existing conventions.

·        Systematic terminology for materials composition and features, including composition, morphology and size.

·        Toxicity effects, environmental impact and risk assessment, including environmental health and safety, reference standards for testing and controls and testing methods for toxicity.

·        Metrology, methods of analysis and standards test methods, including particle size, shape, number and distribution.

B. ASTM International

ASTM International established a new technical committee, Committee E56 on Nanotechnology, that is to develop standards and guidance for nanotechnology and nanomaterials and to coordinate existing ASTM standardization with respect to nanotechnology needs. Committee E56’s membership roster represents twelve countries.

The committee is divided into these six technical subcommittees:

·        Terminology and Nomenclature

·        Characterization

·        Environmental and Occupational Health and Safety

·        International Law and Intellectual Property

·        Liaison and International Cooperation

·        Standards of Care/Product Stewardship

Committee E56 currently plans to develop terminology that will create a “language” for the industry. This is the committee’s first step in its commitment to developing a series of nanotechnology standards that will serve as the global documents of choice. The committee believes that once a common language exists to describe the chemical compositions and physical forms of nanostructures, then technical communication and public outreach will improve.

To facilitate the development of this terminology, ASTM recently signed partnership agreements with the Institute of Electrical and Electronics Engineers (IEEE), the American Society of Mechanical Engineers (ASME) and NSF International. These agreements will help to eliminate redundant resource allocation among standards organizations, group technical experts in a single standards development venue and help to create a global terminology document in terms of input and application.

Conclusion

As nanotechnology continues to emerge, SH&E professionals, regulatory agencies and the insurance industry must combine their efforts to reduce the health and safety risks of occupational and environmental nanoparticle exposure. Thorough standardization and risk analysis of nanotechnology will allow this new science to reach its full potential.


Works and Websites Consulted

Delaney, Helen. “How to Make Your ASTM Standard the Standard the World Uses,” ASTM Standardization News, April 2005, p. 21.

Parsons, Jim. “Small Wonders, Big Questions,” The Synergist, American Industrial Hygiene Association, 2004.

Reynolds, Glenn Harlan. “Forward to the Future: Nanotechnology and Regulatory Policy,” Pacific Research Institute, 2002.

“Nanotechnology: Small Matter, Many Unknowns,” Swiss Reinsurance Company, 2004.

http://www.ansi.org

http://www.astm.org

http://www.cdc.gov/niosh/topics/nanotech/

http://www.hazards.org/nanotech/safety.htm