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EurekAlert! Nanotechnology Portal

Past Transcripts:

Environmental Impact of Nanotechnology

Nanotechnology and Medicine

The Science of Nanofabrication


Dr. Phil Szuromi (moderator):

Good morning, and welcome to EurekAlert's on-line chat on the environmental impacts of nanotechnology. I’m Phil Szuromi, and I will be moderating our discussion with our two experts, Mark Wiesner and Nancy Monteiro-Riviere. Mark Wiesner is the Director of the Environmental and Energy Systems Institute at Rice University in Houston, Texas. He is one of the pioneers in applying membrane processes to environmental separations and water treatment. He has studied not only how nanomaterials can be used to improve membranes, but also what happens to nanomaterials once they enter the environment. Nancy Monteiro-Riviere is a toxicologist at North Carolina State University Center for Chemical Toxicology Research and Pharmacokinetics, in Raleigh, North Carolina. She has worked with a number of in vitro models to mimic human skin, including perfused porcine skin flaps. In particular, she looks at how the exposure of skin (both toxicity and absorption) to nanomaterials may impact occupational safety. Mark, Nancy, welcome.



Dr. Mark Wiesner:

Hello.



Dr. Nancy Monteiro-Riviere:

Hi.



Dr. Phil Szuromi (moderator):

We will get to the submitted questions in a moment, but I’d like to open by giving you both a chance to briefly give us an overview of what you see as the most important environmental and safety problems that we have to address right now. A lot has been said about “potential impacts” of nanotechnology, but what impacts are already out there in the lab, the workplace, and the environment?



Dr. Mark Wiesner:

From my perspective, independent of any risk that nanomaterials or nanotech may or may not have, the immediate environmental concern is making sure that the nanomaterials industry evolves as one that is environmentally benign, so it may not have anything to do with the nanomaterials themselves, but rather the environmental impacts of the production of nanomaterials. That would be my primary near-term concern. In addition, there is, of course, a need for good scientific information on how nanomaterials may move in the environment and what their effects may be on health or ecosystems. Neither are well understood.



Dr. Nancy Monteiro-Riviere:

I'd like to address the importance of nanomaterials as far as relevant studies need to be conducted before the industry progresses too far. In other words, the toxicology of nanomaterials is not fully understood at this time. There are too many unknowns to investigate nanomaterials in terms of exposure. We need to investigate how nanomaterials are exposed to the environment and the workplace. My concern is workplace environment and occupational exposure.



Marie Powers, NanoBiotech News, mpowers655@aol.com:

Of the types of nano drug delivery systems (heat-activated nanoparticles, Quantum dots, gold nanoshells, nanoengineered silicon, etc.) now in development, does one have a greater potential environmental impact than others? Why or why not, and in what way?



Dr. Mark Wiesner:

Many quantum dots are made from heavy metals, and those heavy metals are a known environmental concern. Any medical waste would need to be managed.



Dr. Nancy Monteiro-Riviere:

I think that right now it's in the pilot stages.



Charles Q. Choi, New York:

What preventative measures could nanotech require that are unique from other pollutants and toxins -- e.g. is the fact they are so small mean they can escape filters? What makes nanoparticles toxic in a way unique from other materials? Or do many of the considerations that apply for toxic molecules apply for nanoparticles as well?



Dr. Nancy Monteiro-Riviere:

We first have to understand if there is a potential risk to toxicity. Like any unknown toxin, you want to proceed with caution. Because nanomaterials have such unique properties, they may react very differently from a chemical perspective. They may result in unique toxicity.



Dr. Phil Szuromi (moderator):

So Nancy, in the United States, the FDA or EPA doesn't regulate nanomaterials?



Dr. Nancy Monteiro-Riviere:

I think the EPA and FDA haven't set any guidelines yet because they are not sure of the specific toxicology caused by these materials.



Dr. Nancy Monteiro-Riviere:

The problem with this one is that nanoparticles don't fall under a specific drug category, so they sort of fall through the cracks. Nanoparticles will be regulated based on what therapeutic goal they are targeting.



Dr. Mark Wiesner:

I think the question really addresses the two important elements of risk. When we evaluate any new material, we need to look at exposure and effect. The first part of the question has to do with mobility of nanomaterials and therefore their ability to create exposure in the environment. And in that regard, as with toxicity, you can't speak about nanomaterials or nanoparticles as a uniform group of materials. Every one is likely to be different. Also, just because they're small doesn't mean they will escape filters or be mobile, in fact small sometimes means things are less mobile. What will often define mobility is actually the surface chemistry of the particles. As to the toxicity, I think that in Nancy's comments, the operative word is "may". For the most part, all we have is speculation on toxicity. Some materials are likely to be toxic and some are likely to be completely benign, but we don't know.



Dr. Mark Wiesner:

Finally, to address Phil's question about the FDA and EPA, what's interesting about regulating these nanoparticles is that we have neither the technology to regulate them nor the nomenclature to designate them. So that confounds our ability to regulate them.



Dr. Mark Wiesner:

Talking about the technology, it's not to regulate them but rather to measure them. So, in other words, if you knew that a given nanomaterial should be regulated, because you discovered that it was both toxic and had a high potential for exposure, information which, by the way, is completely lacking right now. But, if we had this information, then you would want to be able to measure it so you could enforce a regulation, and you would want to be able to describe it so that you could mention it in a regulation, but we have neither the system of nomenclature for nanomaterials or, in all cases, the technology for measuring these materials in practical terms.



Dr. Nancy Monteiro-Riviere:

My point on the FDA and EPA is that nanoparticles will be regulated by their potential use, not just by their size. That is, for a cosmetic versus a cardiovascular drug. To effectively regulate nanomaterials, guidelines for defining unique toxicological properties would have to be instituted consistently across FDA and EPA centers.



Natasha Loder, The Economist, London:

Does nanotechnology need better regulation?



Dr. Mark Wiesner:

It goes back to the issue of, if you found it necessary to regulate it, how would you regulate it, being that we don't have the tools to?



Dr. Phil Szuromi (moderator):

Whose responsibility is it to develop the tools?



Dr. Nancy Monteiro-Riviere:

There would have to be some kind of interagency consistencies.



Dr. Mark Wiesner:

One part of that answer is that the international community of nanomaterials researchers need to develop a nomenclature for these materials such as is being developed by IUPAC. But the more immediate issue is ensuring that nanomaterial production is clean. So that it's not about the nanomaterials themselves, but the materials we use to make the nanomaterials.



Dr. Phil Szuromi (moderator):

Can you give me an example of what you mean by clean and unclean?



Dr. Mark Wiesner:

Well, for example, if you use heavy metals to make quantum dots, you want to make sure that you manage the use and disposal of the input and waste of the production process.



Dr. Nancy Monteiro-Riviere:

I just would like to address the regulation specifically. There needs to be interagency consistency on how these are approached. I do not believe that the proper expertise exists in any one agency. The problem that could result in differing approaches is based on lack of familiarity with the unique properties of nanomaterials. Since we are so early in this field, now is the time to develop rational regulations using consistent nomenclature and not be overreactive to the hype of unknown toxicity.



Pat Phibbs, BNA D.C.:

What do you think of the actions that the National Toxicology Program has already and will be continuing to take to understand how to test nanoparticles and then to test them? On a similar vein, what do you think about the ANSI efforts to develop a common nomenclature?



Dr. Nancy Monteiro-Riviere:

The NTP has made an excellent start. It is a good organization to be undertaking these tasks. For those who don't know, the NTP is the part of NIH that deals with toxicology.



Dr. Mark Wiesner:

As far as I know, they are coordinating their efforts with IUPAC. This is a critical and important thing to do, establishing the panel that ANSI discussed.



Dr. Nancy Monteiro-Riviere:

NTP is developing a broad-based research program to address the potential human health hazards associated with the manufacturing of nanomaterials. So, their whole research program is evaluating the toxicological properties of many nanomaterial classes.



Liz Kalaugher, nanotechweb.org:

Given that research into the effects of nanomaterials on the human body is still ongoing, please comment on the use of nanotechnology in products such as sunscreens and cosmetics.



Dr. Mark Wiesner:

Again the issue is: Can you talk about nanomaterials as just one class of materials?



Dr. Mark Wiesner:

I do know that in conversations I've had with one personal care product manufacturer, they have a tremendous amount of in-house data on products under development that is oriented towards making sure the products are safe and their liability is minimized, at best, when products go to market.



Dr. Nancy Monteiro-Riviere:

The use of cosmetics and sunscreens has been heavily tested in the past. Most of the nanomaterials that are in these cosmetics are zinc- or titanium- based. They have been tested using classic toxicity screens. They have been regulated based on their chemical composition, not on their size. I have been talking with some of the FDA people who are reevaluating this at the current time. The FDA cosmetics division has an interest in this field.



Pat Phibbs, BNA:

There are many university students working with nanoparticles, and some scientists have told me these students don't always take the precautions they should. Are you aware of any incidents in which a student's health has been affected by his or her work with nanoparticles?



Dr. Mark Wiesner:

I know of no incident and, as this issue has become more prominent, our university has issued explicit guidelines for ensuring that proper laboratory procedures are followed in handling these and other materials.



Dr. Nancy Monteiro-Riviere:

I'm not aware of any either, and I'd like to assume that students are taking proper precautionary steps and wearing proper personal protection equipment (PPE).



eva opitz, freelancer Freiburg Germany:

Lately I had an interview with a German Professor for nanobiotechnology. He said that we know very little how nanotubes and nanoparticles decompose and that they are extremely solid. What do you know about that?



Dr. Mark Wiesner:

We have ongoing studies, financed through the Center for Biological and Environmental Nanotechnology, that have had as their goal the degradation of carbon based nanomaterials (fullerines). And, to my knowledge, this work has not yet shown degradation of those materials by bacteria or fungi. Mineral nanoparticles would have potentially another fate, that being dissolution. And we are also studying the aggregation and deposition of nanoparticles as a basis for understanding their mobility, exposure, and configuration as presented to biological entities.



Charles Q. Choi, New York:

What are physical factors governing how toxic a nanoparticle, nanotube, etc., might be? Aside from the basic fact that if you introduce a material to a cell in vitro, it can prove toxic, what about factors come to mind -- e.g. the range the nanoparticle can travel in air or water, duration before decay, whether it is made more or less toxic upon absorption by species, the concentration, whether in vitro effects are more or less potent as in vivo effects.



Dr. Nancy Monteiro-Riviere:

I think that a unique property of many carbon nanomaterials is their hydrophobicity. This allows them to interact with lipid membranes that are common to all cell types. My recent studies have shown that chemically unmodified multi-wall carbon nanotubes are not optimized for drug delivery, and could be taken up by skin cells, known as keratinocytes. This results in the accumulation of exposed cells and these studies need to be conducted.



Dr. Nancy Monteiro-Riviere:

...Could oral exposure in the environment cause the nanomaterial uptake into tissue in food animals?



Dr. Nancy Monteiro-Riviere:

...We do not know how organisms are able to eliminate these nanotubes from the body.



Dr. Mark Wiesner:

Again, the question needs to be addressed in consideration of toxicity on one hand and exposure on the other. My own work on mobility of nanomaterials in water suggests that nanomaterials such as fullerines will have limited mobility in aqueous systems. However, functionalized or derivatized versions of these same materials have more affinity for water and, therefore, potentially an ability to travel further. What is unknown is how these materials will interact with the soup of materials naturally present in water, such as degradation products of leaves, products from bacteria and others. We believe that these materials can drastically change or perhaps dominate the properties of nanomaterials in nature. In other words, it might be that nanomaterials, once released in nature, take on a natural coat.



Dr. Nancy Monteiro-Riviere:

My concern is that the fish eat [the "soup" described above], and the people eat the fish.



D.C.:

The Department of Defense has already conducted field trials of nano-engineered iron particles using them to treat ground water contaminated with TCE. Have any studies been conducted to determine the status of the environment before and then after this treatment to determine whether the nano iron particles affected microbes or other parts of the environment?



Dr. Mark Wiesner:

The nanoparticles used in the DOD study are similar to iron nanoparticles that are found throughout natural aquatic environments. Some bacteria even produce iron nanoparticles. My primary concern would not be with the release of these kinds of particles into a natural environment.



Dr. Mark Wiesner:

The danger presented by TCE is known, therefore I'd be more concerned about that.



Dr. Nancy Monteiro-Riviere:

When I was at the EPA "Nanotechnology Science to Achieve Results" Workshop, several investigators talked about these iron particles used to remediate TCE.



Mustak Hossain, The Daily Star, Dhaka, Bangladesh:

How can technologically developing countries benefit from nanotechnology? Are there any initiatives from developed countries to pioneer technology to bridge the gap between advanced and developing countries?



Dr. Mark Wiesner:

Nanotech is one of several examples of opportunities for what are referred to as "leapfrog" technologies, where the most modern and efficient technologies can be put in place today rather than move through an evolution of technologies as have occurred in so called "developed nations." The standard example is developing countries using cell phones. Examples where there is potential for leapfrog technologies that are enabled by nanotechnologies include: advanced processes for water treatment, energy generation, energy transmission and storage, and improved building materials. The list could go on forever.



Dr. Nancy Monteiro-Riviere:

My concern with nanotechnology in developing countries would be that these countries maintain occupational and environmental safety guidelines to ensure that working with nanomaterials in developing these industries would not create problems that could be avoided.



Dr. Mark Wiesner:

I would just add that I agree with that and that those same concerns are important in developed countries as well.



VA:

My question is about nanotechnology being used in the semiconductor industry, but not in the area of medicine/biology. Is it because the perception that it's "safe" to apply nanotechnology to wires, but not yet safe to humans?



Dr. Mark Wiesner:

I think that the driving force for application in one area verses another is driven by what are perceived as advantages of a given use of the nanomaterials themselves rather than a judgment of where they may be safer or more dangerous. But safety and benefit to health is obviously always the primary goal in medicine.



Dr. Nancy Monteiro-Riviere:

I would also guess that, since physicists and engineers make nanomaterials, they are also familiar with the electronic applications. Biologists are not often plugged into these areas, and the National Academy of Sciences Keck Futures Initiatives was a good move to get these communities together.



Bethany Halford, Chemical & Engineering News:

How confident are you that proper personal protection equipment provides sufficient protection in the lab or workplace given that nanomaterials are so varied and that often little is known about new nanomaterials?



Dr. Mark Wiesner:

I think that the question is interesting and that it would be useful to evaluate this equipment in challenge tests with specific nanomaterials.



Dr. Nancy Monteiro-Riviere:

I agree. I think that additional studies focused on specific materials under specific exposure scenarios are needed. These would include assessing gloves, respirators and other personal protection equipment.



Dr. Phil Szuromi (moderator):

In working with nanoparticles and nanotubes in the lab, if these things are used in a fume hood, do they get into the outside air?



Dr. Mark Wiesner:

If you were working with gold dust, would you put it in a fume hood? If these materials can easily be carried away by the air, it's not where you want to work with them.



Dr. Nancy Monteiro-Riviere:

We have a multi-stage filtered hood that could help filter some of these particles. However, this is still unknown. Chemical safety guidelines would require toxicology studies to be under a hood.



Dr. Mark Wiesner:

Is that true, working with fine silica particles?



Dr. Nancy Monteiro-Riviere:

As a toxicologist, we do everything under the hood. We're required.



Pat Phibbs, BNA D.C.:

To build upon Mustak Hossain's question. If you are familiar with the Nanotechnology and the Poor Initiative being developed by the Meridian Institute with Canadian Government and private foundation funding, can you speak to what you would hope it would accomplish.



Dr. Mark Wiesner:

I'm not familiar with it.



Pye Chamberlayne, Shenandoah River bend called Calmes Neck:

What aspects of nanotechnology do you think will most importantly affect the military and non-military security fields?



Dr. Mark Wiesner:

There's a tremendous amount of work going on for applications of nanotech to the military and security fields. For example, technologies for sensing and monitoring quality of water and air, protective coatings, treatment technologies for removing technologies from water and air, improved body armor, coatings on military vehicles and aircraft that may be either protective or adaptive to detection, and many, many more.



Dr. Nancy Monteiro-Riviere:

Nanomaterials are used to make sensors to improve the detection, sensitivity and selectivity of chemical and biological agents, such as anthrax, sulfur mustard and nerve agents. They are also used in some explosives and insensitive munitions, and in some of the coatings in bullet-proof vests. The list could go on and on...



Pat Phibbs, BNA D.C.:

What do you think of the Royal Society's recommendation that, until more is understood about nanoparticles' effects on the environment, they should not be released in to the environment?



Dr. Mark Wiesner:

I would answer that in two parts. First, again, not all nanomaterials are equal. Some nanoparticles are naturally found in the environment. Releasing those nanomaterials into the environment, as in the case of iron nanoparticles to clean up TCE and groundwater, may be warranted. Second, as a general rule, it would seem prudent to avoid releasing nanomaterials into the environment until we understand their potential for transport, exposure and impact.



Dr. Nancy Monteiro-Riviere:

I agree that if they already exist in nature, the risk of adverse effects is lower than in novel particles. However, we need to make sure they do not get released into areas of the environment in which they do not normally occur.



Charles Q. Choi, New York:

Who do you see as the major organizations and consortia focusing on the potential environmental impact of nanotechnology, in the academic, government, industry and nonprofit sectors? For instance, besides Rice, the EPA, ICON and ETC come to mind.



Dr. Mark Wiesner:

There are other organizations as well. The EU, and I know specifically within the EU, France, has launched initiatives for funding in this area, although the funding for this is small even in comparison with the U.S. budget for research on environmental impact. The group of the French researchers are tied into Rice, and we are part of the International Consortium for Environmental Nanotechnology Research, which includes members from France's nuclear agency, several universities, and the CNRS.



Dr. Nancy Monteiro-Riviere:

As a toxicologist for occupational exposure, NIOSH would be the responsible agency. For drugs, it would be the FDA's Center for Toxicological Research. Academic organizations, such as ACS, SETAC, SOT, and IUTOX are interested and support informational programs. Broader organizations such as the National Academies have the desire and expertise to address this.



Cate Alexander, National Nanotechnology Coordination Office:

Toxicology research as well as other research critical to risk assessment--i.e. fate, transport and exposure --is being funded by the US government in increasing proportions. Please see http://www.nano.gov/html/facts/EHS.htm for information on specific projects.

Getting a precise funding figure is difficult as the estimated $80 million in funding by the NIH includes both medical applications and impacts within the same grants. We are trying to get a more precise figure. The data on the NNI website also does not include the recent $4 million in new funding from the EPA. It also does not include the recently announced National Cancer Institute laboratory funding of $144 million for the characterization of nanoscale materials, which will greatly advance knowledge for toxicological purposes. An update of this page is in the works.

Also please note that NIOSH will be releasing guidelines for handling of nanomaterials within the next few months.



Dr. Phil Szuromi (moderator):

So what would you see as the appropriate U.S. and international funding commitment to toxicology and environmental issues in nanotech, and how does this compare to what we are doing now?



Dr. Mark Wiesner:

I think that as a general policy, the amount of investment in research that addresses health, environmental, and societal impacts of new technologies such as nanotechnology is controversial. Certainly, the percentage of investment out of the total research budget in a new technology initiative should be greater than zero, but it has to be less than one hundred percent, otherwise we don't have any new technologies. It's very difficult to know what the percentage is because of the way the budgets are counted. For example, if you develop a new medical application, and you look at the toxicity of a material in that medical application, and that information on toxicity is useful in understanding environmental exposure and toxicity, do you count that research as medical development, or as environmental impact? The answer is moot, but that ambiguity doesn't make it easier to formulate the policy.



Dr. Nancy Monteiro-Riviere:

Funding of developing novel nanotech operations far outstrips that which needs to be done to define their safety. Early industrial efforts are solely focused on proof of concept to gain additional investment. Toxicology efforts are not supported at this stage. This needs to be more balanced if we are to avoid problems in the future.



Dee Ann Divis, UPI Washington DC:

Given the difficulties you have outlined this morning on monitoring and regulating nanomaterials, what actions would you take to get ahead of potential problems? Develop new testing and monitoring methods? Craft new guidelines or regulations? What is the most important thing to do now and who do you think should take the lead on such efforts?



Dr. Mark Wiesner:

I believe that it's too early to craft regulation. The research to inform regulatory policy is insufficient. What's immediately needed is broad-based education in the need to fabricate nanomaterials in an environmentally benign fashion and vigilance as to the uses of these materials in our society. Research on effects to human health and ecosystems and mobility and exposure of nanomaterials is critical to get ahead of potential problems. As far as who should take the lead on such efforts, there is a need for industry, particularly start-ups, to play a role in developing this information, with active aid in terms of research support from governments.



Dr. Nancy Monteiro-Riviere:

I agree with Mark's statement. We need studies focused on specific materials, manufacturing processes, and exposure scenarios to define what needs to be regulated. How do we fold these into existing regulatory structures, where nanomaterials may have applications? We need to standardize nomenclature. We need to ensure that all relevant agencies are communicating with one another. Finally, we need to avoid redundancy and provide a clear regulatory path if this technology is to proceed.



Dr. Phil Szuromi (moderator):

Nancy, Mark, we thank you for your time and your thoughtful answers and comments. You've outlined where we are on these issues, and the work that still needs to be done to understand the effects of nanomaterials.