Category: Nanotoxicology

EU logoAs various articles on this blog (Search: EU) have demonstrated over the past couple of years, the EU has been more proactive than the U.S. in targeting potential health and environmental risks posed to consumers by nanomaterials and seeking to generate and compile relevant and helpful information with an eye toward appropriate regulation.  The EU scientific panel is now calling for comments on opinions of the EU Scientific Committee on Consumer Safety (SCCS) on several nanosubstances used as sunscreens in cosmetics.

The opinions posted for comment indicate what is known about these substances and point to the gaps in the studies.  For example, with regard to dermal absorption of titanium dioxide nanoparticles, SCCS states, in part: 

            “[T]here is a body of open literature on this subject. The evidence from these studies supports the conclusion that TiO2 nanoparticles are unlikely to penetrate across the skin to reach viable cells of the epidermis. . . . Studies have also shown that TiO2 nanoparticles do not penetrate the (simulated) sunburnt skin.

            - Despite the extensive database showing a general lack of TiO2 nanoparticle absorption via the dermal route, there are a few gaps in the knowledge. For example, it is not clear whether TiO2 nanoparticles will be able to penetrate through cuts and bruises, or over repeated or long term applications of a sunscreen formulation.

            - A number of studies have indicated that TiO2 nanoparticle can enter the hair follicles and sweat glands, and that they may remain there for a number of days. This is a scenarioin which TiO2 nanoparticles are likely to get and remain in a close proximity to the living cells for a length of time. A photocatalytic nanoparticle in such a situation may cause . . . potential harmful effects when exposed to sunlight. . . . [M]ore data would be needed to justify the use of those TiO2 nanoparticles in skin applications that have a considerablelevel of photocatalytic activity.”  (Scientific Committee on Consumer Safety SCCS,Opinion on Titanium Dioxide (nano form), p. 97)

The document also indicates the need for study of the potential of these substances of the nano-related properties of the substances to be mutagenic or genotoxic.  (p. 97-98)

These few small examples of the more extensive information contained in the opinions gives a sense of where the SCCS’s attention is currently on nanosubstances in cosmetics, which is one of the most pervasive uses of nanosubstances in consumer use.  With study of such materials moving along in laboratories around the world, it is essential that the information be collected and evaluated to determine what risks, if any, may be presented to consumers by the nanoscale properties of the substances.  The EU is moving in the right direction.

All of the SCCS opinions are available at

http://bit.ly/hVulJJ

 

Lab beakerOne of the hallmarks of scientific knowledge is the ability of researchers to replicate results.  This has eluded scientists studying the health effects of exposure to nanomaterials for a variety of reasons.  Among the factors are:  the unavailability of standardized engineered nanomaterials for testing; differences among the many manufacturers of nanomaterials; lack of standard protocols; and variations in toxicity among particles due to the way the particles behave in certain situations. 

To attempt to resolve these problems, dozens of researchers from universities and NIOSH participated in what has been called the NanGo Consortium to conduct health studies on engineered nanomaterials using the same materials and developing standard protocols.  The program was developed by the National Institute of Environmental Health Sciences (NIEHS).

The inter-laboratory, multi-investigator Consortium defined some of the challenges it faced as follows:

“In addition to dose, there are multiple factors that influence the toxicity of ENMs, including surface characteristics, charge, and shape. Size alone is a major determinant as many bulk materials that are relatively inert become toxic when produced at the nanoscale. . . . Determination of which ENMs will present the greatest potential threat to human health depends on relative toxicity, and on the potential for exposure.”  (pp. 5-6)

The Consortium conducted two broad sets of studies.  The first involved rats and mice exposed to carbon nanotubes and titanium dioxide, and measured pulmonary inflammation.  The Consortium concluded:  “The results presented and discussed herein demonstrate that a standard protocol can be used across multiple laboratories to yield similar results in the pulmonary inflammatory response.” (pp. 6-7)  The researchers are optimistic that with this start, there will be opportunities to determine the impact that exposure to nanomaterials may have on human at the preventive stage.

The second study examined the effects of carbon nanotubes, titanium dioxide, and zinc oxide in vitro in laboratory container studies.  The Consortium noted:  “A significant finding of this study was that the development of harmonized in vitro assay protocols made it possible to achieve reproducible results among different laboratories.” (p. 16)  This study, the Consortium concluded, “provides new information on the relative in vitro bioactivity of a large group of diverse ENM that can be used to inform future strategies for in vitro testing and predicting in vivo outcomes.” (p. 6)

These studies move researchers in the direction of being able to replicate results and ultimately draw reliable conclusions about the potential health hazards of exposure to nanomaterials, leading to effective regulation.

The NIEHS NanoGo Consortium reports are available at

http://ehp.niehs.nih.gov/wp-content/uploads/121/4/ehp.1205693.pdf

http://ehp.niehs.nih.gov/wp-content/uploads/121/4/ehp.1306561.pdf

 

nano 3On November 30, 2010, the American Industrial Hygiene Association (AIHA), in commenting on the draft 2010 strategic plan of the National Nanotechnology Initiative (NNI), recommended that nanomaterial safety be incorporated in graduate curricula.  AIHA lamented that many recent American graduate school degree recipients are ill-equipped to effectively assess the industrial health and safety risks of nanomaterials in industrial settings.  And, as AIHA pointed out, many recent grads have already had significant exposures to nanomaterials.

 The beginnings of a solution are relatively simple.  AIHA has recommended that the consortium of federal agencies involved in implementing the NNI strategic plan develop guidelines for graduate research programs.  The draft plan itself contains suggestions for actions by the National Institute for Occupational Safety and Health (NIOSH), such as investigation of a broad spectrum of nanomaterials and recommendation of safe exposure limits.

 The full solution may be much more complex, however.

 This issue reminds me of a broader concern that receives news coverage from time to time.  Maybe not often enough.  We frequently hear that the United States continues to lag behind the rest of the developed world in student science performance.  The Organization for Economic Cooperation and Development (OECD), of which the United States is a member, keeps track of such things.  In the most recent rankings of science performance among OECD nations (updated rankings due soon), the United States continued to be below average and ranked 22.

 The bar is being set a little higher for science performance in the schools with the proliferation of nanotechnologies and their highly sophisticated use in many products and medical procedures.  AIHA has said that many newly minted scientists “are unaware of the fundamentals of nanomaterial safety.”  Beyond assuring that nanomaterial safety fundamentals are taught and implemented in graduate programs, nanotechnology and nanomaterial safety should become a part of the basic science curriculum at every relevant level of American education.

 Source:

Greg Hellman, Industrical Hygienists Say Nanomaterial Safety Should be Part of Graduate Curriculums, BNA Chemical Regulation Rptr, Nov. 30, 2010

 Some information on OECD rankings is available at

http://ourtimes.wordpress.com/2008/04/10/oecd-education-rankings/

Getty Images

Getty Images

The good news is that both the European Union and Australia are moving toward adopting definitions of “nanomaterials” that will be used for setting standards for and developing regulation of these substances.  The news that may give some people cause for thought is that the definitions are not identical.

 This post is an update to my original post on the subject and looks at two definitions.  Consider the following.

  The European Commission, in a draft recommendation currently available for public consultation, has defined “nanomaterial” as

 “a material that meets at least one of the following criteria:

- consists of particles, with one or more external dimensions in the size range 1 nm – 100 nm for more than 1% of their number size distribution;

- has internal or surface structures in one or more dimensions in the size range 1 nm – 100 nm;

- has a specific surface area by volume greater than 60 m²/cm³, excluding materials consisting of particles with a size lower than 1 nm.”  (Art. 2, Sec. 1)

 The European Commission’s draft also indicated that the definition will be used “as an overarching, broadly applicable reference term for any Union communication or legislation addressing nanomaterials.”  (Preamble, 12)  Moreover, the Commission has recommended that the definition be reviewed frequently and adjusted to reflect scientific advances.  (Preamble, 7)

The Australian government is using a different definition, however, in a new administrative process published by the National Industrial Chemicals Notification and Assessment Scheme (NICNAS).  The procedure requires new chemical manufacturers and importers to notify NICNAS of their intent to manufacture or import nanoscale chemicals and defines “nanomaterials” as

 “industrial materials intentionally produced, manufactured, or engineered to have unique properties or specific composition at the nanoscale, that is a size range typically between 1 nm and 100 nm, and is either a nano-object (i.e. that is confined in one, two, or three dimensions at the nanoscale) or is structured (i.e. having an internal or surface structure at the nanoscale”

 Further, the Notes to the working definition add that “where size distribution shows 10% or more of a substance (based on number of particles) is at the nanoscale, NICNAS will consider this substance to be a nanomaterial for risk assessment purposes.”

 The different definitions raise several issues:

 ●  The difference between 1%, per the European Commission, and 10%, per Australia’s NICNAS, could mean that many more substances would fall within the definition under EU standards than under Australia’s standards.

 ●  In an increasingly global economy, should manufacturers of nanomaterials be required to meet separate standards based upon definitions that vary from government to government?  One answer to this question is, Why not?  Manufacturers of chemicals and other products are frequently asked to meet different standards around the world, where some countries may be quite stringent and others lenient.  The tobacco industry moved a large segment of its business to Asia in response to litigation and regulation in the U.S., hoping to take advantage of a different regulatory climate.  Conversely, however, varying regulatory standards for chemicals can create difficulties and confusion for manufacturers and importers.

 ●  Nanotechnology is not only new to regulation as a discrete category, but will also be regulated in the international arena in the first instance.  Wouldn’t consistency, at least in the definition of nanomaterials, best serve this process?

 ●  Nanotechnology is widely viewed as beneficial with broad potential across all sectors of modern life.  Consistent definitions of what constitutes nanomaterials would assist firms in making business decisions going forward.

 Perhaps different definitions are only a step along the way toward ultimate agreement and consistency in the global arena.  Let’s hope so.

 The European Commission draft is available at

http://ec.europa.eu/environment/consultations/nanomaterials.htm

 The NICNAS processes are available at

http://www.nicnas.gov.au/Publications/Chemical_Gazette/pdf/2010oct_whole.pdf#page=14

http://www.techwall.org

http://www.techwall.org

The course of asbestos litigation is well known, as is the fact that there appears to be no end in sight.  Is nanotechnology producing the next asbestos?  Some groups are working to prevent nanoparticle litigation from following in the steps of asbestos litigation.

In 2009, the United Kingdom’s Institute of Occupational Medicine (IOM) issued a report asking the question whether High Aspect Ratio Nanoparticles (HARN) – most notably, carbon nanotubes – create some of the same health risks as asbestos fibers.  The fiber-like features of HARN, although man-made rather than naturally occurring, may or may not interact with the human body in asbestos-like ways. The importance of determining whether HARN raise similar health risks cannot be overstated.  These issues have yet to be resolved, with potential health risks lurking in the interim.  As is often the case, development of new technology has flown past the scientific community’s ability to determine and assess the technology’s risks.

Looking back at the history of asbestos litigation, some burning questions need resolution sooner rather than later.  For example:

●  Do HARN fibers remain in vivo or do they degrade before disease processes are initiated?

●  If HARN are shown to persist in the body, what is the likely impact on workers?  In the asbestos context, the impact was seen in thousands of workers who developed debilitating progressive obstructive lung disease and/or malignant mesothelioma.  Do HARN have the capacity to produce similar health problems?

●  Even if HARN do not appear to behave directly like asbestos fibers, could HARN cause other, unknown, adverse health effects?

●  What broader impact might HARN have outside the workplace, including consumer and environmental exposures?

Are we headed down the same litigation road with HARN that we traveled with asbestos?

The asbestos litigation debacle in the United States began modestly enough with workers’ compensation claims, which were first denied and eventually routinely paid.  When asbestos insulation workers successfully brought actions against the manufacturers of the products they used in the workplace, the litigation expanded exponentially and has continued to challenge the court systems.

How can we avoid another asbestos?  The answer begins with research, knowledge, and awareness.

Lab beakerThe New York Times recently published an article reviewing the state of research on the adverse health effects of the chemical bisphenol-A (known as BPA), which is found in plastic used for many consumer products.  BPA is a hot topic right now, both in the health and political arenas.  The reason is that BPA has been shown in some studies to mimic the hormone estrogen, which is considered an “endocrine disruptor” capable of causing harm to humans.  But whether BPA, in mimicking estrogen, actually causes harm has yet to be determined.

Some of the concerns about conducting and interpreting the health studies on BPA are instructive as we go forward with studies on the health effects of nanosubstances.

 Some particularly instructive observations in the article are:

 1.  Some scientists have noted the conflicting results in existing studies.  Some have suggested that the inconsistent results are, at least in part, a function of different laboratories studying the chemical in different ways:  “Animal strains, doses, methods of exposure and the results being measured – as crude as body weight or as delicate as gene expression in the brain – have all varied, making it difficult or impossible to reconcile the findings,” according to the article.

 2.  Even when experiments appear to be conducted identically, the interpretations may vary among scientists of different disciplines, using different standards.

 3.  In studying BPA and many other chemicals and substances (including nanosubstances), it is particularly important to be aware of the different ways the substance may act on adults, children, and fetuses exposed in utero.  Moreover, adverse impacts on fetuses include not just fetal development; a person born with fetal exposure could develop future exposure-related health problems during his or her lifetime.

 4.  Private laboratories tend to be the first to use new advances in research, while the government researchers tend to lag behind.  It is not clear which type is likely to yield the more accurate results – the new techniques or the tried-and-true techniques.

 In thinking about studying the health effects of nanotechnology-based substances, it is important to keep in mind these points.  Because nanosubstances are available for so many and varied uses, determining the actual health impacts will take time, money, and a coordinated effort among scientific disciplines.

Now is the time to move forward with just such a coordinated effort.

 The article on BPA is available at:

http://www.nytimes.com/2010/09/07/science/07bpa.html?th&emc=th

Wikimedia

Wikimedia

What do the Gulf oil spill, the attacks on the World Trade Center on September 11, 2001, and nanotechnology have in common?  On the surface, it would seem to be nothing.  But all three involve responses to potential health and environmental threats that are instructive about how we as a society respond to such threats.  Collectively, they raise some important issues regarding how our society views health and environmental risks in general.

 Don’t get me wrong.  In no way am I suggesting that nanotechnology is comparable to the disasters at Ground Zero or in the Gulf.  Rather, I am asking that you look at how government and funded research institutes manage long-term health and environmental effects that occur as a result of chronic low-dose exposures over time.  The potential health hazards of nanotechnology fall into the long-term category.  We don’t expect to see any acute health problems associated with nanotechnology, but we should be concerned about long-term exposures, and existing efforts to study the effects should be expanded.

 Let’s contrast what happens when there is a disaster.

 On August 19, 2010, administration officials reaffirmed their commitment to the recovery and restoration of the Gulf in the aftermath of the Deepwater Horizon oil rig explosion and the subsequent movement of oil into the waters and the ecosystems of the Gulf.  The media outlets have been full of video, photographs, and articles about the efforts of many organizations, companies, and governmental entities to clean up and minimize the potential harm to natural resources, the environment, and all forms of life.

 Not so long ago, something similar went on at Ground Zero in the aftermath of the collapse of the World Trade Center towers following the 9/11 terrorist attacks.  Early on, the focus of efforts at Ground Zero was on the search for survivors.  On September 29, the focus turned to recovery and cleanup, including removal of debris.  But even before that date, the federal, state, and local governments were engaged in managing the environmental disaster that resulted from the release of hazardous substances into the air, including asbestos, silica, lead, mercury, polycyclic aromatic hydrocarbons (PAHs), dioxin, polyvinyl chloride (PVC), Freon, and polychlorinated biphenyls (PCBs), to name a few.  Workers from FDNY, NYPD, Port Authority of New York and New Jersey, emergency medical personnel, and a host of volunteers worked at the site.

 It is easy to assign massive resources to the acute phase of a disaster, but much harder to sustain interest and funding as time goes on.  Eventually the media will move on to other stories now that the Macondo well is just about sealed, as it eventually did when the cleanup at Ground Zero was completed.  Funds have been established to make payments, lawsuits commenced.  But what lingers is the reality of long-term health effects that could emerge over time – ecosystem damage or cancer or other health risks.  Society has a certain myopia about such things.  Perhaps it is human nature to not want to think about the health problems that could arise years down the line.

 The protracted task of developing valid scientific studies on the health effects of any exposures, including nanoparticles, and interpreting the results is as essential as responding to the acute phase of a disaster.  Disasters like the Gulf spill and 9/11 suggest a kind of false dichotomy – that acute harms are more worthy of recognition in the law than chronic long-term harms.  The long-term harms may seem less urgent, but there is nevertheless an urgency about them as well.

 For example, following the Exxon Valdez oil spill in 1989, no concerted effort was made to assess the health effects of the cleanup on workers.  Years later, surveys told the story of respiratory and neurological illness.  This month, the National Institute of Environmental Health Sciences announced it would begin a study of the potential health effects of exposures of workers and residents as a result of the Gulf oil spill.  Even in the 9/11 context, where health screenings of Ground Zero responders have been ongoing since 2002, and a data base has been established, acceptable compensation has come nearly a decade after the disaster.  The law is slower to recognize the harms from chronic exposures, and slower to act to both compensate the injured and prevent further harm.  Clearly, some of this is a result of symptoms and other harms emerging over time.  But this is all the more reason to be vigilant and investigative from the start.

 Far from the spotlight of a high-profile disaster, and in the absence of a clearly exposed population to screen, studies on the health and environmental effects of exposures to substances about which we know little is essential.

 As mentioned, nanotechnology is not a disaster.  Far from it.  It is a means for creating better medical therapies, making some of our technology perform better, and offering consumers desirable features in everyday products such as textiles and cosmetics.  But this does not eliminate the need to make a concerted effort to study the long-term health and environmental effects of nanoparticles and nanomaterials.  No matter how long it takes; no matter how far out of the spotlight.

 For those interested in knowing more about the toxic aftermath of Ground Zero, see my article, Toxic Torts at Ground Zero, 39 ARIZ. ST. L.J. 383 (2007).

On the need for studies of the health impact of the Gulf spill, see

Gina M. Solomon & Sarah Janssen, Health Effects of the Gulf Oil Spill, J.A.M.A. (Aug. 16, 2010), available at http://jama.ama-assn.org/cgi/content/full/jama.2010.1254v1

Wikimedia

Wikimedia

Let’s face it:  Industry would just as soon be left alone.  But in this modern society, that’s simply not possible.  Government regulation is necessary to advance policy goals, which include the safety and health of the general public.  Industry recognizes this, of course, and wants to be able to undertake its activities knowing what the government requires (mandatory) and expects (voluntary) of it.  This is even more critical in the world of global commerce, where an industry may be subject to varying – and sometimes even contradictory – standards in different countries.  In the United States alone, separate state regulation of nanotechnology could lead to confusing and incompatible standards.

 Isn’t the nanotechnology industry entitled to a uniform set of definitions to be able to interpret and apply regulatory standards?

 This is the gist of an article that appeared recently in the BNA Daily Environment Report at

Pat Rizzuto & Bill Pritchard, Industry Developing Nanoengineered Goods Frustrated by Regulators’ Lack of Definitions, 93 Daily Envt. Rpt. (BNA) B-1 (May 17, 2010) (available by subscription)

In recent months, various bodies have been attempting to address this issue, but it is likely that nothing representing a consensus may emerge soon.  Yet, there may be some urgency to the task.  As reported in the article, one industry executive in a company developing electronics using nanomaterials said that regulatory certainty is necessary in determining whether to move its operations from the United States to China.  The article went on to discuss the efforts that many countries are making to develop standard definitions for nanomaterials.  This, of course, is only a precursor to regulation.  There is currently no agreement as to what the size of a particle means in the regulatory world and whether a workable definition should be based solely on size.

The International Organization for Standardization (ISO) hopes to have a set of definitions by the end of the year.  The article goes on to indicate that a coalition of businesses may become involved in developing standardized definitions.

 The European Commission’s Joint Research Commission (JRC) released a report July 2, 2010, emphasizing the need for a uniform definition of the term “nanomaterial” and providing “practical guidance for a definition for regulatory purposes.”  The report recommends the following criteria, suggesting that a definition:

  •  only concern particulate nanomaterials,
  •  be broadly applicable in EU legislation, and in line with other approaches worldwide,
  • use size as the only defining property.

European Commission, Joint Research Centre, Considerations on a Definition of Nanomaterial for Regulatory Purposes 5 (2010).

 The JRC report may be accessed at

 http://ec.europa.eu/dgs/jrc/downloads/jrc_reference_report_201007_nanomaterials.pdf

 Clearly, we have not yet arrived at the point of being able to speak the same nanolanguage around the world.  Every nanostep helps, however.  But time is of the essence.  And consensus is crucial.

www.h20technologies.com

www.h20technologies.com

In the ongoing effort to determine how best to regulate nanotechnology, the first and easiest suggestion is to use existing laws and regulations that were developed for chemicals.  Some observers believe that the labyrinth of existing regulations (through FDA, EPA, OSHA, and other agencies) is sufficient to regulate nanotechnologies and nanomaterials that may pose hazards to workers or the public.  In a recent report issued by the Government Accountability Office (GAO), the GAO noted that the “use of nanomaterials in products is growing faster than our understanding of the risks these materials pose to human health and the environment” (p. 49)

 U.S. Gov’t Accountability Office, Nanotechnology:  Nanomaterials are Widely Used in Commerce, but EPA Faces Challenges in Regulating Risk (2010) (report to the Chair, Senate Committee on Env’t and Public Works), available at

http://www.gao.gov/new.items/d10549.pdf

 The GAO report indicated that EPA believes it has the authority and ability to regulate manufactured nanomaterials through existing federal statutes, i.e. Clean Air Act, Clean Water Act, RCRA, TSCA, and FIFRA, and that it has the authority to manage cleanups of releases of nanomaterials that may be endangering human health or the environment, pursuant to CERCLA.  EPA is currently attempting to work within the structure of these laws to address the potential hazards of nanomaterials, but the GAO report observes that there are significantly greater difficulties in addressing the potential hazards of nanotechnology than in addressing the hazards of conventional chemicals:

 ●  The hazards of nanomaterials vary with the size and shape of the particle.

 ●  Nanomaterials may be more reactive with other chemicals.

 ●  EPA officials say that “it is difficult to assess the risk of nanomaterials that are released into the environment because these materials are so varied and it is difficult to make generalizations about how they will behave once they are released.”  (p. 28)

 ●  Only a limited number of studies have been conducted to date on the hazards of nanomaterials, and existing studies on a nanomaterial constructed in one manner may not be relevant to the same nanomaterial constructed in a different manner.  In other words, “studies of similar nanomaterials may not be comparable.”  (p. 29)

 ●  Many nanomaterials have not yet been studied.

 ●  The scientific community does not currently possess all of the necessary tools, “such as models or measurement technologies” (p. 30), to even characterize or describe the nanomaterials properly, let alone fully understand how the nanoparticles behave.

 ●  Some federal environmental statutes are better suited than others to address the potential hazards of nanomaterials.

 This brief summary of the obstacles to effective analysis of the hazards of nanomaterials – and, accordingly, to effective regulation of nanomaterials – raises an important threshold question for the legal, scientific, and regulatory communities:

 Will effective regulation come from addressing nanomaterials within the existing statutory framework, which was designed for chemicals and other conventional materials?

 This question must be raised, addressed, and vigorously debated.  Right now, there is no clear answer to that important question.  If a new approach, separate from the approaches used for conventional chemicals, is more likely to result in effective regulation sooner, rather than later, then common sense may dictate going that route.  The debate should begin now, not after another decade has passed.

www.singularityhub.com

www.singularityhub.com

Last week, the Organisation for Economic Co-operation and Development (OECD) issued its updated manual to support the safety testing of manufactured nanomaterials.  The OECD describes itself as follows:

 “ The Organisation for Economic Co-operation and Development (OECD) is an intergovernmental organization in which representatives of 31 industrialised countries in North America, Europe and the Asia and Pacific region, as well as the European Commission, meet to co-ordinate and harmonise policies, discuss issues of mutual concern, and work together to respond to international problems.”

 The United States is a member country of OECD.

 The Guidance Manual for the Testing of Manufactured Nanomaterials:  OECD’s Sponsorship Programme is a product of the Joint Meeting of the Chemicals Committee and the Working Party on Chemicals, Pesticides and Biotechnology of the OECD.

 One goal of the projects contributing to the manual was to determine whether test guidelines for the safety of traditional chemicals may be suitable for testing the safety of manufactured nanomaterials.  Researchers are particularly interested in the role that particle size and specific area may play in the resulting toxicity of the nanomaterials.

What strikes me here – and when reading other sources on the safety of nanomaterials – is the need to focus on particle size as a factor in determining the health and safety risks.  In some respects, this is reminiscent of asbestos research, in which the size, shape, and characteristics of the asbestos fibers, as well as the manner in which they are bonded to or contained in the product, define the health risks associated with asbestos exposure.  It took a half century of asbestos research to arrive at an understanding of the mechanisms by which the fibers cause illness, including malignancies, and other physiological changes that may not result in illness.

The hope for nanotechnology is that this discussion and investigation are taking place sooner, rather than later, and that there is a concerted effort internationally to coordinate and share research.  Although unregulated nanomaterials are in extensive use already, and many more uses of nanotechnology become available each day, it is worth recognizing the efforts being made to identify the risks at an early stage.

Perhaps the asbestos example taught us something after all.

The manual may be accessed at:

http://www.oecd.org/department/0,3355,en_2649_37015404_1_1_1_1_1,00.html