Science AMA Series: I'm Greg Lowry, Investigator and Deputy Director with the Center for the Environmental Implications of NanoTechnology. We do research on the behavior of nanoparticles in the environment and their implications, and am here today to talk about it. AMA!



Has anyone at CEINT examined the impact of microfiber pollution from the fashion textile industry?

Dr. Sherri A. Mason at SUNY Fredonia for example has done quite a bit of research on microbead and other plastics pollution in freshwater bodies ...tracking it downstream right up to deposits in fish and other wildlife. And, related I think are studies that look at the shedding of synthetic fibers from garments like fleece which produce similar effects.

However I am not certain whether research has been done on other forms of synthetic fiber pollution such as the 'heat absorption' fabrics that are now very popular for sports and everyday activity. One of the better known brands & hit products from Japan is called 'HEATTECH' from Fast Retailing aka UNIQLO (TSE 9983) to the point that major textile firms like TORAY (TSE 3401) have large plants exclusively dedicated to churning out miles of HEATTECH.

They used to be a bit more forthcoming on the technological aspects of this proprietary fiber blend which includes nano-technology (? Ag+) 'anti-bacterial' treatments but most definitely not simply a function of its physical weave (of acrylic, rayon, polyurethane and polyester). Similar to the studies conduced by Dr. Mason and others on microbeads and fleece ending up in the ecosystem via the simple act of washing one's clothes, the micro-fibers shed each time a HEATTECH garment or similar heat absorption fabric is washed results in measureable amounts of fibers ending up in the flesh of fish. However, hardly any publicized reseearch on this ....

I know it could sound overly alarmist but this nano-fiber pollution might be close to the acquatic-equivalent of asbestos contamination...

Do you have any thoughts on this matter or are you aware of any relevant research you could direct us to?


We have not looked at micro (or nano) fibers released from synthetic fabrics as part of CEINT. However, the topic of microplastics in the environment is one of emerging concern, and small fibers shed from synthetic fabrics would certainly qualify as a micro (or nano) plastic. I am not familiar with the fate and effects of microplastics or microfibers so I cannot really shed light on this except to say that it should probably be studied more given the very LARGE quantities of synthetic fibers that are produced and used throughout the world. Thanks for the question.

Perfect! I'm currently taking a class on the use of nanomaterials in medicine, and we've discussed environmental impact at length. As regards silver and gold nanoparticles:

  1. Do we know the rate at which they degrade into ionic gold and silver?

  2. Do we know what impact the release of antimicrobial NPs into the environment will affect microbial communities?

  3. Do you see a way to hold producers responsible for the elimination of nanomaterials post-medical-use?

Thanks so much for doing this AMA!


Hi. Good questions. Metal nanoparticles like silver are subject to transformations in the environment, e.g. dissolution or sulfidation. Some like silver transform quickly. Others, like gold are less reactive and transform slowly. There is not a lot of data available on the RATES of these transformations. For Ag NPs, they may oxidize and dissolve to release Ag ions, but those ions are quickly complexed by organic matter of sulfidized. There are a number of studies on how addition of Ag or Cu NPs affects microbial communities. However, there are differing opinions on the severity of the effects because the environmental conditions are not the same between studies. In general, changes in microbial community structure and function can occur upon exposure to NPs made from elements known to be antimicrobial, e.g. Ag and Cu. I am not sure that the quantity of nanomaterials used in medicine and biomedical devices will lead to significant environmental exposures post medical use. It may be better to look at higher volume applications.

I've actually been thinking about this as it relates to the current plastics crisis affecting the world's oceans. Do you think it would be possible to create some kind of environmentally benign swarm of plastic-consuming nanobots?


I have seen some recent work by Joseph Wang in ES Nano about self-propelled nanobots for environmental remediation. However, we are a long ways from being able to harness this ability of the scale of oceans. A better approach would be to innovate synthetic fibers so that they are recyclable or biodegradable into benign materials at the end of their life.

Hi Greg. One of the biggest issues of nano - research is trying to measure presence of nanoparticles in situ. What does the near future hold for us being able to accurately know what nanomaterials are present in the environment around us? Are there any new methods or technologies being applied that improve the characterization process in the field?


Indeed, it will be important to locate and quantify the presence of nanomaterials in complex environmental (e.g. soil) and biological (e.g. cells) matrices. This is a very active area of research. Researchers at CEINT such as Lee Ferguson, and others including Frank von der Kammer at University of Vienna, and Jim Ranville at Colorado School of Mines (and many others, sorry if I left you off of the list) are working on isolating and characterizing these nanomaterials from environmental matrices. Currently, single particle ICP-MS detection and quantification of NPs recovered from these matrices is a leading candidate for analysis. For metals, isotope ratios in the NPs can be used to distinguish engineered nanomaterials from naturally occurring ones. Check out the research by the people mentioned above for more information about methods and types of particles being characterized.

There has been some interest in iron oxide nanoparticles in the context of pollution lately, after several news stories made bold claims on the topic. However, it is repeatedly mentioned that there is no actual evidence of said particles doing any harm, and the PNAS paper under discussion is still not available.

Considering the fact that iron oxide nanoparticles have been approved for use as MRI contrast agents, etc. for decades, and are regularly injected into patients without issue, how much of this is sensationalism, and how much is of legitimate concern?


CEINT has worked for the past 8 years to be able to answer questions like this. We all want answers to the simple question of "are NPs toxic or harmful?" As noted by Wildslayer66, NPs are not all the same. Ultimately, it is the properties of those NPs that will (or will not) invoke some toxic response. For the bigger question, "Is this all hype?". We have found in CEINT that just because a material is small, it is not innately toxic. We have also found that nanomaterials are massively abundant in nature, e.g. ferrihydrite is an abundant natural nano-Fe oxide. We have been living with these types of materials since the beginning of humankind. It is likely that we have developed natural defenses to these materials. However, many nanomaterials are not naturally occurring, have unique shapes or assemblies of atoms that biology has not yet seen. We still do not know mechanistically how these novel materials interact with organisms or invoke a biological response. Understanding this, and ultimately harnessing that understanding to make better medicines or safer products remains a goals of nanotechnology research.

As an average consumer, should the use of nanoparticles be something I am more attentive of (with concern for the potentially harmful effects on the environment of the products I buy)?

If so, what nanoparticles in consumer products are the worst offenders and how may I best avoid them? Thanks!


Consumers should be aware of the composition of the products they buy to be able to make informed choices. That said, there is no compelling evidence at this point that nanomatrials in consumer products pose any more hazard than many of the other chemicals in commerce. Of course, one always has to be vigilant. Products containing nanomaterials made from elements known to be toxic, e.g. Cd or Pb, should raise some eyebrows. Products that offer opportunities for high exposure, e.g. sprayed chemicals, may also be problematic.

Hi Gary. I've recently completed my PhD in nanoparticles as imaging agents applied to neuroscience. My question is which type of nanoparticles make their way into the environment in the highest volumes? TiO2 from sunscreens or silver from antibacterial/hospital settings? Is there any evidence that coating with PEG reduces toxicity? What aspect ratio or size ranges are the most harmful to particular environments (marine vs soil vs airways)? Thanks for the AMA, feel free to answer as many or as few of these questions as you wish.


Hi. These are good questions. There are a number of papers out (e.g. by Christine Hendren in CEINT, Arturo Keller at UCSB, Bernd Nowack at ETH) that have worked to quantify nanomaterial production rates. Keller, A.A., McFerran, S., Lazareva, A. et al. J Nanopart Res (2013) 15: 1692. doi:10.1007/s11051-013-1692-4

Ag is not high on the list. We make much more TiO2, SiO2, and iron oxides than silver.

I am not a toxicologist so I'll punt of the toxicity question. Particle shape effects are less well explored than e.g. effects of coatings. But there is evidence that shape, e.g. rods and triangular prisms have different toxicity than spheres of the same chemical composition. Admittedly, there is not convergence on which shapes are best. This is an area of research getting more attention lately.

Given the myriad of organic compounds in the environment, how do you tune a particles affinity and selectivity for key pollutants?


Not easily. Improving selectivity of reactive materials or sorbents has been a long-time goal in many disciplines. There are many people trying to modify surfaces of NPs with synthetic organics or with biomolecules to provide targeting. This is not a new problem, but NPs provide greater surface area and the potential to deliver those materials in unique ways.

Does nature herself use nanoparticles in any applications?


I agree with Kopuk_Ucurtma. Nature makes an enormous variety of nanomaterials. Mike Hochella (a co-PI of CEINT) and his students have done the most work trying to catalog these natural nanomaterials, determine their properties, and understand their role in nature. One of the most important outcomes of research into nanomaterial environmental health and safety has been development of new tools to study nanomaterials in the environment, and simply to observe their role in natural biological processes.

is the current depiction of nanotechnology (tiny insect-like robots traveling in swarms to move in and quickly repair problems) anything like the reality? thanks for the AMA!


I agree with wildslayer66. We are still quite a bit away from controlling material at an atomic scale to build the things we'd like. But that does not mean that we cannot get there someday with innovation and investments in the STEM fields. When you walk home tonight and see the moon in the sky, imagine the investment and dedication that it took leading up to 1969 to be able to build a spacecraft, land it on the moon, walk around a bit, then come home. Or when you use your smartphone, think of what it took to have the amazing and powerful machines that we have today. Nanotechnology will someday enable medicines, clean water, sustainable agriculture, and devices that we cannot even imagine today.

Can you describe the regulatory environment currently surrounding the use, development, and disposal of nano particles? I really like the potential of new material properties and medical advancements, but if we let the cat out of the bag before we fully understand the true costs of these new particles... We may be very sorry. And our current track record, especially in the US, is to profit first-ask questions later. Siphon profits away so if a cleanup is needed you're no where around and tax payers will foot the bill.

But in case of nano particles there may be no going back. Case in point, nano silver. Anti microbial, great, lets add it to garments so our stinky bacterial dies. Oh wait, our entire digestive system is bacteria, what if that silver gets into our gut? How about when the garment is washed, nano silver goes to waste water treatment plant.... That uses bacteria to break down our waste. Oh no! Too many companies and people are using nano silver in their clothing and now the bacteria is dead! And the water always gets discharged into the environment.... So now an accumulation of nano silver occurs in our waters (just like all the plastic particles from cosmetics that are being found in our waterways). Is this to far fetched of a scenario? Areas that use surface water for drinking water usually discharge treated waterwater into the same body. It is not far off to think that we will eventually be drinking nano silver that is currently being used. It really feels like we are just living a giant experiment.

I'm an engineer for a waste water treatment plant with an interest in environmental sustainability and technological advancements. Thanks for doing the AMA!


"Traditional" nanoparticles like zinc, silver, and titanium seem to be at the front of research right now. What plans do you have for evaluating engineered nanoparticles used for innovative applications like 3D printing and biomedical devices?


Staying ahead of the development curve is always a challenge. Right now, CEINT and much of the nanoEHS research community is focused on the highest production volumes materials, and those that appear to have the greatest potential for harm. However, we are trying to develop testing methods (Hendren et al., 2015 Sci. Tot. Env. doi:10.1016/j.scitotenv.2015.06.100) and research strategies (e.g. Saleh at al. 2015 ES Nano 2, 11-18 10.1039/C4EN00104D) that can allow us to assess more complex materials and different scenarios.

Has any nano research been done on the behavior or impact of oil spills on riverine systems (wildlife, plants, or people)?


Yes. There are papers by Jamie Lead at University of South Carolina and many others on development of nanoscale sorbents for cleaning up oil spills in freshwater and seawater. E.g. Environ. Sci.: Nano, 2016,3, 780-787 DOI: 10.1039/C5EN00282F. Desiree Plata at Yale is also developing nanoscale sorbets for oil remediation.

What are the health risks of graphene? I read some time ago about the concern of graphene being the new asbestos, for its similarity to damage lungs tissues. How many research are being conducted? Are people (scientists, researchers, engineers etc) aware of this possible problem? Is this taken seriously enough?


There are a lot of people evaluating the toxicity of 1-dimensional and 2-dimensional carbonaceous nanomaterials. Their inhalation toxicity (Nanotoxicology. 2016 Sep;10(7):891-901. doi: 10.3109/17435390) and antimicrobial properties are being evaluated (ACS Nano, 2010, 4 (10), pp 5731–5736 DOI: 10.1021/nn101390x) is certainly being studied.

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