Category Archives: risk

Implications of nanoplastic in the aquatic food chain

As plastic breaks down in the oceans into plastic nanoparticles, they enter the food chain when they are ingested by plankton. Researchers in Sweden have published a study about the process. From a May 23, 2016 news item on ScienceDaily,

Plastic accounts for nearly eighty per cent of all waste found in our oceans, gradually breaking down into smaller and smaller particles. New research from Lund University in Sweden investigates how nanosized plastic particles affect aquatic animals in different parts of the food chain.

“Not very many studies have been done on this topic before. Plastic particles of such a small size are difficult to study,” says Karin Mattsson.

A May 23, 2016 Lund University press release, which originated the news item, provides more detail,

“We tested how polystyrene plastic particles of different sizes, charge and surface affect the zooplankton Daphnia. It turned out that the size of the nanoparticles that were most toxic to the Daphnia in our study was 50 nanometers”, says Karin Mattsson.

Because zooplankton like Daphnia are also food for many other aquatic animals, the researchers wanted to study the effect of plastic particles higher up in the food chain. They found that fish that ate Daphnia containing nanoplastics experienced a change in their predatory behaviour and poor appetite. In several studies, researchers also discovered that the nanoparticles had the ability to cross biological barriers, such as the intestinal wall and brain.

“Although in our study we used much larger amounts of nanoplastic than those present in oceans today, we suspect that plastic particles may be accumulated inside the fish. This means that even low doses could ultimately have a negative effect”, says Karin Mattsson.

Plastic breaks down very slowly in nature, and once the microscopically small plastic particles reach lakes and oceans they are difficult to remove. Plastic particles also bind environmental toxins that can become part of the food chain when consumed accidentally.

“Our research indicates the need for more studies and increased caution in the use of nanoplastics”, she says.

Karin Mattsson is a physicist and her research project was produced in collaboration between the Centre for Environmental and Climate Research, the Division Biochemistry and Structural Biology and the Division of Aquatic Biology at Lund University. Karin Mattsson is also affiliated with NanoLund, where several studies are currently conducted to evaluate the safety of nanoparticles.

Here’s a link to and a citation for a paper published online in 2014 and in print in 2015,

Altered Behavior, Physiology, and Metabolism in Fish Exposed to Polystyrene Nanoparticles by Karin Mattsson, Mikael T. Ekvall, Lars-Anders Hansson, Sara Linse, Anders Malmendal, and Tommy Cedervall. Environ. Sci. Technol., 2015, 49 (1), pp 553–561 DOI: 10.1021/es5053655
Publication Date (Web): November 07, 2014

Copyright © 2014 American Chemical Society

More recently, Karin Mattson has published her PhD thesis on the topic (I believe it is written in Swedish).

Nanoparticles in baby formula

Needle-like particles of hydroxyapatite found in infant formula by ASU researchers. Westerhoff and Schoepf/ASU, CC BY-ND

Needle-like particles of hydroxyapatite found in infant formula by ASU [Arizona State University] researchers. Westerhoff and Schoepf/ASU, CC BY-ND

Nanowerk is featuring an essay about hydroxyapatite nanoparticles in baby formula written by Dr. Andrew Maynard in a May 17, 2016 news item (Note: A link has been removed),

There’s a lot of stuff you’d expect to find in baby formula: proteins, carbs, vitamins, essential minerals. But parents probably wouldn’t anticipate finding extremely small, needle-like particles. Yet this is exactly what a team of scientists here at Arizona State University [ASU] recently discovered.

The research, commissioned and published by Friends of the Earth (FoE) – an environmental advocacy group – analyzed six commonly available off-the-shelf baby formulas (liquid and powder) and found nanometer-scale needle-like particles in three of them. The particles were made of hydroxyapatite – a poorly soluble calcium-rich mineral. Manufacturers use it to regulate acidity in some foods, and it’s also available as a dietary supplement.

Andrew’s May 17, 2016 essay first appeared on The Conversation website,

Looking at these particles at super-high magnification, it’s hard not to feel a little anxious about feeding them to a baby. They appear sharp and dangerous – not the sort of thing that has any place around infants. …

… questions like “should infants be ingesting them?” make a lot of sense. However, as is so often the case, the answers are not quite so straightforward.

Andrew begins by explaining about calcium and hydroxyapatite (from The Conversation),

Calcium is an essential part of a growing infant’s diet, and is a legally required component in formula. But not necessarily in the form of hydroxyapatite nanoparticles.

Hydroxyapatite is a tough, durable mineral. It’s naturally made in our bodies as an essential part of bones and teeth – it’s what makes them so strong. So it’s tempting to assume the substance is safe to eat. But just because our bones and teeth are made of the mineral doesn’t automatically make it safe to ingest outright.

The issue here is what the hydroxyapatite in formula might do before it’s digested, dissolved and reconstituted inside babies’ bodies. The size and shape of the particles ingested has a lot to do with how they behave within a living system.

He then discusses size and shape, which are important at the nanoscale,

Size and shape can make a difference between safe and unsafe when it comes to particles in our food. Small particles aren’t necessarily bad. But they can potentially get to parts of our body that larger ones can’t reach. Think through the gut wall, into the bloodstream, and into organs and cells. Ingested nanoscale particles may be able to interfere with cells – even beneficial gut microbes – in ways that larger particles don’t.

These possibilities don’t necessarily make nanoparticles harmful. Our bodies are pretty well adapted to handling naturally occurring nanoscale particles – you probably ate some last time you had burnt toast (carbon nanoparticles), or poorly washed vegetables (clay nanoparticles from the soil). And of course, how much of a material we’re exposed to is at least as important as how potentially hazardous it is.

Yet there’s a lot we still don’t know about the safety of intentionally engineered nanoparticles in food. Toxicologists have started paying close attention to such particles, just in case their tiny size makes them more harmful than otherwise expected.

Currently, hydroxyapatite is considered safe at the macroscale by the US Food and Drug Administration (FDA). However, the agency has indicated that nanoscale versions of safe materials such as hydroxyapatite may not be safe food additives. From Andrew’s May 17, 2016 essay,

Hydroxyapatite is a tough, durable mineral. It’s naturally made in our bodies as an essential part of bones and teeth – it’s what makes them so strong. So it’s tempting to assume the substance is safe to eat. But just because our bones and teeth are made of the mineral doesn’t automatically make it safe to ingest outright.

The issue here is what the hydroxyapatite in formula might do before it’s digested, dissolved and reconstituted inside babies’ bodies. The size and shape of the particles ingested has a lot to do with how they behave within a living system. Size and shape can make a difference between safe and unsafe when it comes to particles in our food. Small particles aren’t necessarily bad. But they can potentially get to parts of our body that larger ones can’t reach. Think through the gut wall, into the bloodstream, and into organs and cells. Ingested nanoscale particles may be able to interfere with cells – even beneficial gut microbes – in ways that larger particles don’t.These possibilities don’t necessarily make nanoparticles harmful. Our bodies are pretty well adapted to handling naturally occurring nanoscale particles – you probably ate some last time you had burnt toast (carbon nanoparticles), or poorly washed vegetables (clay nanoparticles from the soil). And of course, how much of a material we’re exposed to is at least as important as how potentially hazardous it is.Yet there’s a lot we still don’t know about the safety of intentionally engineered nanoparticles in food. Toxicologists have started paying close attention to such particles, just in case their tiny size makes them more harmful than otherwise expected.

Putting particle size to one side for a moment, hydroxyapatite is classified by the US Food and Drug Administration (FDA) as “Generally Regarded As Safe.” That means it considers the material safe for use in food products – at least in a non-nano form. However, the agency has raised concerns that nanoscale versions of food ingredients may not be as safe as their larger counterparts.Some manufacturers may be interested in the potential benefits of “nanosizing” – such as increasing the uptake of vitamins and minerals, or altering the physical, textural and sensory properties of foods. But because decreasing particle size may also affect product safety, the FDA indicates that intentionally nanosizing already regulated food ingredients could require regulatory reevaluation.In other words, even though non-nanoscale hydroxyapatite is “Generally Regarded As Safe,” according to the FDA, the safety of any nanoscale form of the substance would need to be reevaluated before being added to food products.Despite this size-safety relationship, the FDA confirmed to me that the agency is unaware of any food substance intentionally engineered at the nanoscale that has enough generally available safety data to determine it should be “Generally Regarded As Safe.”Casting further uncertainty on the use of nanoscale hydroxyapatite in food, a 2015 report from the European Scientific Committee on Consumer Safety (SCCS) suggests there may be some cause for concern when it comes to this particular nanomaterial.Prompted by the use of nanoscale hydroxyapatite in dental products to strengthen teeth (which they consider “cosmetic products”), the SCCS reviewed published research on the material’s potential to cause harm. Their conclusion?

The available information indicates that nano-hydroxyapatite in needle-shaped form is of concern in relation to potential toxicity. Therefore, needle-shaped nano-hydroxyapatite should not be used in cosmetic products.

This recommendation was based on a handful of studies, none of which involved exposing people to the substance. Researchers injected hydroxyapatite needles directly into the bloodstream of rats. Others exposed cells outside the body to the material and observed the effects. In each case, there were tantalizing hints that the small particles interfered in some way with normal biological functions. But the results were insufficient to indicate whether the effects were meaningful in people.

As Andrew also notes in his essay, none of the studies examined by the SCCS OEuropean Scientific Committee on Consumer Safety) looked at what happens to nano-hydroxyapatite once it enters your gut and that is what the researchers at Arizona State University were considering (from the May 17, 2016 essay),

The good news is that, according to preliminary studies from ASU researchers, hydroxyapatite needles don’t last long in the digestive system.

This research is still being reviewed for publication. But early indications are that as soon as the needle-like nanoparticles hit the highly acidic fluid in the stomach, they begin to dissolve. So fast in fact, that by the time they leave the stomach – an exceedingly hostile environment – they are no longer the nanoparticles they started out as.

These findings make sense since we know hydroxyapatite dissolves in acids, and small particles typically dissolve faster than larger ones. So maybe nanoscale hydroxyapatite needles in food are safer than they sound.

This doesn’t mean that the nano-needles are completely off the hook, as some of them may get past the stomach intact and reach more vulnerable parts of the gut. But the findings do suggest these ultra-small needle-like particles could be an effective source of dietary calcium – possibly more so than larger or less needle-like particles that may not dissolve as quickly.

Intriguingly, recent research has indicated that calcium phosphate nanoparticles form naturally in our stomachs and go on to be an important part of our immune system. It’s possible that rapidly dissolving hydroxyapatite nano-needles are actually a boon, providing raw material for these natural and essential nanoparticles.

While it’s comforting to know that preliminary research suggests that the hydroxyapatite nanoparticles are likely safe for use in food products, Andrew points out that more needs to be done to insure safety (from the May 17, 2016 essay),

And yet, even if these needle-like hydroxyapatite nanoparticles in infant formula are ultimately a good thing, the FoE report raises a number of unresolved questions. Did the manufacturers knowingly add the nanoparticles to their products? How are they and the FDA ensuring the products’ safety? Do consumers have a right to know when they’re feeding their babies nanoparticles?

Whether the manufacturers knowingly added these particles to their formula is not clear. At this point, it’s not even clear why they might have been added, as hydroxyapatite does not appear to be a substantial source of calcium in most formula. …

And regardless of the benefits and risks of nanoparticles in infant formula, parents have a right to know what’s in the products they’re feeding their children. In Europe, food ingredients must be legally labeled if they are nanoscale. In the U.S., there is no such requirement, leaving American parents to feel somewhat left in the dark by producers, the FDA and policy makers.

As far as I’m aware, the Canadian situation is much the same as the US. If the material is considered safe at the macroscale, there is no requirement to indicate that a nanoscale version of the material is in the product.

I encourage you to read Andrew’s essay in its entirety. As for the FoE report (Nanoparticles in baby formula: Tiny new ingredients are a big concern), that is here.

AquAdvantage salmon (genetically modified) approved for consumption in Canada

This is an update of the AquAdvantage salmon story covered in my Dec. 4, 2015 post (scroll down about 40% of the way). At the time, the US Food and Drug Administration (FDA) had just given approval for consumption of the fish. There was speculation there would be a long hard fight over approval in Canada. This does not seem to have been the case, according to a May 10, 2016 news item announcing Health Canada’s on phys.org,

Canada’s health ministry on Thursday [May 19, 2016] approved a type of genetically modified salmon as safe to eat, making it the first transgenic animal destined for Canadian dinner tables.

This comes six months after US authorities gave the green light to sell the fish in American grocery stores.

The decisions by Health Canada and the US Food and Drug Administration follow two decades of controversy over the fish, which is an Atlantic salmon injected with genes from Pacific Chinook salmon and a fish known as the ocean pout to make it grow faster.

The resulting fish, called AquAdvantage Salmon, is made by AquaBounty Technologies in Massachusetts, and can reach adult size in 16 to 18 months instead of 30 months for normal Atlantic salmon.

A May 19, 2016 BIOTECanada news release on businesswire provides more detail about one of the salmon’s Canadian connections,

Canadian technology emanating from Memorial University developed the AquAdvantage salmon by introducing a growth hormone gene from Chinook salmon into the genome of Atlantic salmon. This results in a salmon which grows faster and reaches market size quicker and AquAdvantage salmon is identical to other farmed salmon. The AquAdvantage salmon also received US FDA approval in November 2015. With the growing world population, AquaBounty is one of many biotechnology companies offering safe and sustainable means to enhance the security and supply of food in the world. AquaBounty has improved the productivity of aquaculture through its use of biotechnology and modern breeding technics that have led to the development of AquAdvantage salmon.

“Importantly, today’s approval is a result of a four year science-based regulatory approval process which involved four federal government departments including Agriculture and AgriFood, Canada Food Inspection Agency, Environment and Climate Change, Fisheries and Oceans and Health which demonstrates the rigour and scope of science based regulatory approvals in Canada. Coupled with the report from the [US] National Academy of Sciences today’s [May 19, 2016] approval clearly demonstrates that genetic engineering of food is not only necessary but also extremely safe,” concluded Casey [Andrew Casey, President and CEO BIOTECanada].

There’s another connection, the salmon hatcheries are based in Prince Edward Island.

While BIOTECanada’s Andrew Casey is crowing about this approval, it should be noted that there was a losing court battle with British Columbia’s Living Oceans Society and Nova Scotia’s Ecology Action Centre both challenging the federal government’s approval. They may have lost battle but, as the cliché goes, ‘the war is not over yet’. There’s an Issue about the lack of labeling and there’s always the  possibility that retailers and/or consumers may decide to boycott the fish.

As for BIOTECanada, there’s this description from the news release,

BIOTECanada is the national industry association with more than 230 members reflecting the diverse nature of Canada’s health, industrial and agricultural biotechnology sectors. In addition to providing significant health benefits for Canadians, the biotechnology industry has quickly become an essential part of the transformation of many traditional cornerstones of the Canadian economy including manufacturing, automotive, energy, aerospace and forestry industries. Biotechnology in all of its applications from health, agriculture and industrial is offering solutions for the collective population.

You can find the BIOTECanada website here.

Personally, I’m a bit ambivalent about it all. I understand the necessity for changing our food production processes but I do think more attention should be paid to consumers’ concerns and that organizations such as BIOTECanada could do a better job of communicating.

New model to track flow of nanomaterials through our air, earth, and water

Just how many tons of nanoparticles are making their way through the environment? Scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) have devised a new model which could help answer that question. From a May 12, 2016 news item on phys.org,

Carbon nanotubes remain attached to materials for years while titanium dioxide and nanozinc are rapidly washed out of cosmetics and accumulate in the ground. Within the National Research Program “Opportunities and Risks of Nanomaterials” (NRP 64) a team led by Empa scientist Bernd Nowack has developed a new model to track the flow of the most important nanomaterials in the environment.

A May 12, 2016 Empa press release by Michael Hagmann, which also originated the news item, provides more detail such as an estimated tonnage for titanium dioxide nanoparticles produced annually in Europe,

How many man-made nanoparticles make their way into the air, earth or water? In order to assess these amounts, a group of researchers led by Bernd Nowack from Empa, the Swiss Federal Laboratories for Materials Science and Technology, has developed a computer model as part of the National Research Program “Opportunities and Risks of Nanomaterials” (NRP 64). “Our estimates offer the best available data at present about the environmental accumulation of nanosilver, nanozinc, nano-tinanium dioxide and carbon nanotubes”, says Nowack.

In contrast to the static calculations hitherto in use, their new, dynamic model does not just take into account the significant growth in the production and use of nanomaterials, but also makes provision for the fact that different nanomaterials are used in different applications. For example, nanozinc and nano-titanium dioxide are found primarily in cosmetics. Roughly half of these nanoparticles find their way into our waste water within the space of a year, and from there they enter into sewage sludge. Carbon nanotubes, however, are integrated into composite materials and are bound in products such as which are immobilized and are thus found for example in tennis racquets and bicycle frames. It can take over ten years before they are released, when these products end up in waste incineration or are recycled.

39,000 metric tons of nanoparticles

The researchers involved in this study come from Empa, ETH Zurich and the University of Zurich. They use an estimated annual production of nano-titanium dioxide across Europe of 39,000 metric tons – considerably more than the total for all other nanomaterials. Their model calculates how much of this enters the atmosphere, surface waters, sediments and the earth, and accumulates there. In the EU, the use of sewage sludge as fertilizer (a practice forbidden in Switzerland) means that nano-titanium dioxide today reaches an average concentration of 61 micrograms per kilo in affected soils.

Knowing the degree of accumulation in the environment is only the first step in the risk assessment of nanomaterials, however. Now this data has to be compared with results of eco-toxicological tests and the statutory thresholds, says Nowack. A risk assessment has not been carried out with his new model so far. Earlier work with data from a static model showed, however, that the concentrations determined for all four nanomaterials investigated are not expected to have any impact on the environment.

But in the case of nanozinc at least, its concentration in the environment is approaching the critical level. This is why this particular nanomaterial has to be given priority in future eco-toxicological studies – even though nanozinc is produced in smaller quantities than nano-titanium dioxide. Furthermore, eco-toxicological tests have until now been carried out primarily with freshwater organisms. The researchers conclude that additional investigations using soil-dwelling organisms are a priority.

Here are links to and citations for papers featuring the work,

Dynamic Probabilistic Modeling of Environmental Emissions of Engineered Nanomaterials by Tian Yin Sun†, Nikolaus A. Bornhöft, Konrad Hungerbühler, and Bernd Nowack. Environ. Sci. Technol., 2016, 50 (9), pp 4701–4711 DOI: 10.1021/acs.est.5b05828 Publication Date (Web): April 04, 2016

Copyright © 2016 American Chemical Society

Probabilistic environmental risk assessment of five nanomaterials (nano-TiO2, nano-Ag, nano-ZnO, CNT, and fullerenes) by Claudia Coll, Dominic Notter, Fadri Gottschalk, Tianyin Sun, Claudia Som, & Bernd Nowack. Nanotoxicology Volume 10, Issue 4, 2016 pages 436-444 DOI: 10.3109/17435390.2015.1073812 Published online: 10 Nov 2015

The first paper, which is listed in Environmental Science & Technology, appears to be open access while the second paper is behind a paywall.

Titanium dioxide nanoparticles have subtle effects on oxidative stress genes?

There’s research from the Georgia Institute of Technology (Georgia Tech; US) suggesting that titanium dioxide nanoparticles may have long term side effects. From a May 10, 2016 news item on ScienceDaily,

A nanoparticle commonly used in food, cosmetics, sunscreen and other products can have subtle effects on the activity of genes expressing enzymes that address oxidative stress inside two types of cells. While the titanium dioxide (TiO2) nanoparticles are considered non-toxic because they don’t kill cells at low concentrations, these cellular effects could add to concerns about long-term exposure to the nanomaterial.

A May 9, 2016 Georgia Tech news release on Newswire (also on EurekAlert), which originated the news item, describes the research in more detail,

Researchers at the Georgia Institute of Technology used high-throughput screening techniques to study the effects of titanium dioxide nanoparticles on the expression of 84 genes related to cellular oxidative stress. Their work found that six genes, four of them from a single gene family, were affected by a 24-hour exposure to the nanoparticles.

The effect was seen in two different kinds of cells exposed to the nanoparticles: human HeLa* cancer cells commonly used in research, and a line of monkey kidney cells. Polystyrene nanoparticles similar in size and surface electrical charge to the titanium dioxide nanoparticles did not produce a similar effect on gene expression.

“This is important because every standard measure of cell health shows that cells are not affected by these titanium dioxide nanoparticles,” said Christine Payne, an associate professor in Georgia Tech’s School of Chemistry and Biochemistry. “Our results show that there is a more subtle change in oxidative stress that could be damaging to cells or lead to long-term changes. This suggests that other nanoparticles should be screened for similar low-level effects.”

The research was reported online May 6 in the Journal of Physical Chemistry C. The work was supported by the National Institutes of Health (NIH) through the HERCULES Center at Emory University, and by a Vasser Woolley Fellowship.

Titanium dioxide nanoparticles help make powdered donuts white, protect skin from the sun’s rays and reflect light in painted surfaces. In concentrations commonly used, they are considered non-toxic, though several other studies have raised concern about potential effects on gene expression that may not directly impact the short-term health of cells.

To determine whether the nanoparticles could affect genes involved in managing oxidative stress in cells, Payne and colleague Melissa Kemp – an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University – designed a study to broadly evaluate the nanoparticle’s impact on the two cell lines.

Working with graduate students Sabiha Runa and Dipesh Khanal, they separately incubated HeLa cells and monkey kidney cells with titanium oxide at levels 100 times less than the minimum concentration known to initiate effects on cell health. After incubating the cells for 24 hours with the TiO2, the cells were lysed and their contents analyzed using both PCR and Western Blot techniques to study the expression of 84 genes associated with the cells’ ability to address oxidative processes.

Payne and Kemp were surprised to find changes in the expression of six genes, including four from the peroxiredoxin family of enzymes that helps cells degrade hydrogen peroxide, a byproduct of cellular oxidation processes. Too much hydrogen peroxide can create oxidative stress which can damage DNA and other molecules.

The effect measured was significant – changes of about 50 percent in enzyme expression compared to cells that had not been incubated with nanoparticles. The tests were conducted in triplicate and produced similar results each time.

“One thing that was really surprising was that this whole family of proteins was affected, though some were up-regulated and some were down-regulated,” Kemp said. “These were all related proteins, so the question is why they would respond differently to the presence of the nanoparticles.”

The researchers aren’t sure how the nanoparticles bind with the cells, but they suspect it may involve the protein corona that surrounds the particles. The corona is made up of serum proteins that normally serve as food for the cells, but adsorb to the nanoparticles in the culture medium. The corona proteins have a protective effect on the cells, but may also serve as a way for the nanoparticles to bind to cell receptors.

Titanium dioxide is well known for its photo-catalytic effects under ultraviolet light, but the researchers don’t think that’s in play here because their culturing was done in ambient light – or in the dark. The individual nanoparticles had diameters of about 21 nanometers, but in cell culture formed much larger aggregates.

In future work, Payne and Kemp hope to learn more about the interaction, including where the enzyme-producing proteins are located in the cells. For that, they may use HyPer-Tau, a reporter protein they developed to track the location of hydrogen peroxide within cells.

The research suggests a re-evaluation may be necessary for other nanoparticles that could create subtle effects even though they’ve been deemed safe.

“Earlier work had suggested that nanoparticles can lead to oxidative stress, but nobody had really looked at this level and at so many different proteins at the same time,” Payne said. “Our research looked at such low concentrations that it does raise questions about what else might be affected. We looked specifically at oxidative stress, but there may be other genes that are affected, too.”

Those subtle differences may matter when they’re added to other factors.

“Oxidative stress is implicated in all kinds of inflammatory and immune responses,” Kemp noted. “While the titanium dioxide alone may just be modulating the expression levels of this family of proteins, if that is happening at the same time you have other types of oxidative stress for different reasons, then you may have a cumulative effect.”

*HeLa cells are named for Henrietta Lacks who unknowingly donated her immortal cell line to medical research. You can find more about the  story on the Oprah Winfrey website, which features an excerpt from the Rebecca Skloot book “The Immortal Life of Henrietta Lacks.” By the way, on May 2, 2016 it was announced that Oprah Winfrey would star in a movie for HBO as Henrietta Lacks’ daughter in an adaptation of the Rebecca Skloot book. You can read more about the proposed production in a May 3, 2016 article by Benjamin Lee for the Guardian.

Getting back to titanium dioxide nanoparticles and their possible long term effects, here’s a link to and a citation for the Georgia Tech team’s paper,

TiO2 Nanoparticles Alter the Expression of Peroxiredoxin Antioxidant Genes by Sabiha Runa, Dipesh Khanal, Melissa L. Kemp‡, and Christine K. Payne. J. Phys. Chem. C, Article ASAP DOI: 10.1021/acs.jpcc.6b01939 Publication Date (Web): April 21, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Nanosafety Cluster newsletter—excerpts from the Spring 2016 issue

The European Commission’s NanoSafety Cluster Newsletter (no.7) Spring 2016 edition is some 50 pp. long and it provides a roundup of activities and forthcoming events. Here are a few excerpts,

“Closer to the Market” Roadmap (CTTM) now finalised

Hot off the press! the Cluster’s “Closer to the Market” Roadmap (CTTM)  is  a  multi-dimensional,  stepwise  plan  targeting  a framework to deliver safe nano-enabled products to the market. After some years of discussions, several consultations of a huge number of experts in the nanosafety-field, conferences at which the issue of market implementation of nanotechnologies was talked  about,  writing  hours/days,  and  finally  two public consultation rounds, the CTTM is now finalized.

As stated in the Executive Summary: “Nano-products and nano-enabled applications need a clear and easy-to-follow human and environmental safety framework for the development along the innovation chain from initial idea to market and beyond that facilitates  navigation  through  the  complex  regulatory and approval processes under which different product categories fall.

Download it here, and get involved in its implementation through the Cluster!
Authors: Andreas Falk* 1, Christa Schimpel1, Andrea Haase3, Benoît Hazebrouck4, Carlos Fito López5, Adriele Prina-Mello6, Kai Savolainen7, Adriënne Sips8, Jesús M. Lopez de Ipiña10, Iseult Lynch11, Costas Charitidis12, Visser Germ13

NanoDefine hosts Synergy Workshop with NSC projects

NanoDefine  organised  the  2nd Nanosafety  Cluster  (NSC)  Synergy Workshop  at  the  Netherlands  House  for Education  and  Research  in Brussels  on  2nd  February  2016. The  aim  was  to  identify  overlaps and synergies existing between different projects that could develop into
outstanding cooperation opportunities.

One central issue was the building of a common ontology and a European framework for data management and analysis, as planned within eNanoMapper, to facilitate a closer interdisciplinary collaboration between  NSC projects and to better address the need for proper data storage, analysis and sharing (Open Access).

Unexpectedly, there’s a Canadian connection,

Discovering protocols for nanoparticles: the soils case
NanoFASE WP7 & NanoSafety Cluster WG3 Exposure

In NanoFASE, of course, we focus on the exposure to nanomaterials. Having consistent and meaningful protocols to characterize the fate of nanomaterials in different environments is therefore of great interest to us. Soils and sediments are in this respect very cumbersome. Also in the case of conventional chemicals has the development of  protocols for fate description in terrestrial systems been a long route.

The special considerations of nanomaterials make this job even harder. For instance, how does one handle the fact that the interaction between soils and nanoparticles is always out of equilibrium? How does one distinguish between the nanoparticles that are still mobile and those that are attached to soil?

In the case of conventional chemicals, a single measurement of a filtered soil suspension often suffices to find the mobile fraction, as long one is sure that equilibrium has been attained. Equilibrium never occurs in the case of  nanoparticles, and the distinction between attached/suspended particles is analytically less clear to do.

Current activity in NanoFASE is focusing at finding protocols to characterize this interaction. Not only does the protocol have to provide meaningful parameters that can be used, e.g. in modelling, but also the method itself should be fast and cheap enough so that a lot of data can be collected in a reasonable amount of time. NanoFASE is  in a good position to do this, because of its focus on fate and because of the many international collaborators.

For  instance,  the Swedish  Agricultural  University (Uppsala)  is  collaborating  with  McGill  University (Montreal, Canada [emphasis mine]), an advisory partner to NanoFASE, in developing the OECD [Organization for Economic Cooperation and Development] protocol for column tests (OECD test nr 312:  “Leaching in soil columns”). The effort is led by Yasir Sultan from Environment Canada and by Karlheinz Weinfurtner from the Frauenhofer institute in Germany. Initial results show the transport of nanomaterials in soil columns to be very limited.

The OECD protocol therefore does not often lead to measurable breakthrough curves that can be modelled to provide information about  nanomaterial  mobility  in  soils  and  most  likely  requires adaptations  to  account  for  the  relatively  low mobility  of  typical pristine nanomaterials.

OECD 312 prescribes to use 40 cm columns, which is most likely too long to show a breakthrough in the case of nanoparticles. Testing in NanoFASE will therefore focus on working with shorter columns and also investigating the effect of the flow speed.

The progress and the results of this action will be reported on our website (www.nanofase.eu).

ENM [engineered nanomaterial] Transformation in and Release from Managed Waste Streams (WP5): The NanoFASE pilot Wastewater Treatment Plant is up and running and producing sludge – soon we’ll be dosing with nanoparticles to test “real world” aging.

Now, wastewater,

ENM [engineered nanomaterial] Transformation in and Release from Managed Waste Streams (WP5): The NanoFASE pilot Wastewater Treatment Plant is up and running and producing sludge – soon we’ll be dosing with nanoparticles to test “real world” aging.

WP5 led by Ralf Kaegi of EAWAG [Swiss Federal Institute of Aquatic Science and Technology] (Switzerland) will establish transformation and release rates of ENM during their passage through different reactors. We are focusing on wastewater treatment plants (WWTPs), solid waste and dedicated sewage sludge incinerators as well as landfills (see figure below). Additionally, lab-scale experiments using pristine and well characterized materials, representing the realistic fate relevant forms at each stage, will allow us to obtain a mechanistic understanding of the transformation processes in waste treatment reactors. Our experimental results will feed directly into the development of a mathematical model describing the transformation and transfer of ENMs through the investigated reactors.

I’m including this since I’ve been following the ‘silver nanoparticle story’ for some time,

NanoMILE publication update: NanoMILE on the air and on the cover

Dramatic  differences  in  behavior  of  nano-silver during  the  initial  wash  cycle  and  for  its  further dissolution/transformation potential over time depending on detergent composition and form.

In an effort to better relate nanomaterial aging procedures to those which they are most likely to undergo during the life cycle of nano-enhanced products, in this paper we describe the various transformations which are possible when exposing Ag engineered nanoparticles (ENPs) to a suite of commercially available washing detergents (Figure 1). While Ag ENP transformation and washing of textiles has received considerable attention in recent years, our study is novel in that we (1) used several commercially available detergents allowing us to estimate the various changes possible in individual homes and commercial washing settings; (2) we have continued  method  development  of  state  of  the  art nanometrology techniques, including single particle ICP-MS, for the detection and characterization of ENPs in complex media; and (3) we were able to provide novel additions to the knowledge base of the environmental nanotechnology research community both in terms of the analytical methods (e.g. the first time ENP aggregates have been definitively analyzed via single particle ICP-MS) and broadening the scope of “real world” conditions that should be considered when understanding AgENP through their life cycle.

Our findings, which were recently published in Environmental Science and Toxicology (2015, 49: 9665), indicate that the washing detergent chemistry causes dramatic differences in ENP behavior during the initial wash cycle and has ramifications for the dissolution/transformation potential of the Ag ENPs over time (see Figure 2). The use of silver as an  antimicrobial  treatment  in  textiles  continues  to garner  considerable  attention.  Last  year  we  published  a manuscript in ACS Nano that considered how various silver treatments to textiles (conventional and nano) both release  nano-sized  material  after  the  wash  cycle  with  similar chemical  characteristics.  That  study  essentially conveyed that multiple silver treatments would become more similar through the product life cycle. Our newest  work expands this by investigating one silver ENP under various washing conditions thereby creating more varied silver products as an end result.

Fascinating stuff if you’ve been following the issues around nanotechnology and safety.

Towards the end of the newsletter on pp. 46-48, they list opportunities for partnerships, collaboration, and research posts and they list websites where you can check out job opportunities. Good Luck!

Not enough talk about nano risks?

It’s not often that a controversy amongst visual artists intersects with a story about carbon nanotubes, risk, and the roles that  scientists play in public discourse.

Nano risks

Dr. Andrew Maynard, Director of the Risk Innovation Lab at Arizona State University, opens the discussion in a March 29, 2016 article for the appropriately named website, The Conversation (Note: Links have been removed),

Back in 2008, carbon nanotubes – exceptionally fine tubes made up of carbon atoms – were making headlines. A new study from the U.K. had just shown that, under some conditions, these long, slender fiber-like tubes could cause harm in mice in the same way that some asbestos fibers do.

As a collaborator in that study, I was at the time heavily involved in exploring the risks and benefits of novel nanoscale materials. Back then, there was intense interest in understanding how materials like this could be dangerous, and how they might be made safer.

Fast forward to a few weeks ago, when carbon nanotubes were in the news again, but for a very different reason. This time, there was outrage not over potential risks, but because the artist Anish Kapoor had been given exclusive rights to a carbon nanotube-based pigment – claimed to be one of the blackest pigments ever made.

The worries that even nanotech proponents had in the early 2000s about possible health and environmental risks – and their impact on investor and consumer confidence – seem to have evaporated.

I had covered the carbon nanotube-based coating in a March 14, 2016 posting here,

Surrey NanoSystems (UK) is billing their Vantablack as the world’s blackest coating and they now have a new product in that line according to a March 10, 2016 company press release (received via email),

A whole range of products can now take advantage of Vantablack’s astonishing characteristics, thanks to the development of a new spray version of the world’s blackest coating material. The new substance, Vantablack S-VIS, is easily applied at large scale to virtually any surface, whilst still delivering the proven performance of Vantablack.

Oddly, the company news release notes Vantablack S-VIS could be used in consumer products while including the recommendation that it not be used in products where physical contact or abrasion is possible,

… Its ability to deceive the eye also opens up a range of design possibilities to enhance styling and appearance in luxury goods and jewellery [emphasis mine].

… “We are continuing to develop the technology, and the new sprayable version really does open up the possibility of applying super-black coatings in many more types of airborne or terrestrial applications. Possibilities include commercial products such as cameras, [emphasis mine] equipment requiring improved performance in a smaller form factor, as well as differentiating the look of products by means of the coating’s unique aesthetic appearance. It’s a major step forward compared with today’s commercial absorber coatings.”

The structured surface of Vantablack S-VIS means that it is not recommended for applications where it is subject to physical contact or abrasion. [emphasis mine] Ideally, it should be applied to surfaces that are protected, either within a packaged product, or behind a glass or other protective layer.

Presumably Surrey NanoSystems is looking at ways to make its Vantablack S-VIS capable of being used in products such as jewellery, cameras, and other consumers products where physical contact and abrasions are a strong possibility.

Andrew has pointed questions about using Vantablack S-VIS in new applications (from his March 29, 2016 article; Note: Links have been removed),

The original Vantablack was a specialty carbon nanotube coating designed for use in space, to reduce the amount of stray light entering space-based optical instruments. It was this far remove from any people that made Vantablack seem pretty safe. Whatever its toxicity, the chances of it getting into someone’s body were vanishingly small. It wasn’t nontoxic, but the risk of exposure was minuscule.

In contrast, Vantablack S-VIS is designed to be used where people might touch it, inhale it, or even (unintentionally) ingest it.

To be clear, Vantablack S-VIS is not comparable to asbestos – the carbon nanotubes it relies on are too short, and too tightly bound together to behave like needle-like asbestos fibers. Yet its combination of novelty, low density and high surface area, together with the possibility of human exposure, still raise serious risk questions.

For instance, as an expert in nanomaterial safety, I would want to know how readily the spray – or bits of material dislodged from surfaces – can be inhaled or otherwise get into the body; what these particles look like; what is known about how their size, shape, surface area, porosity and chemistry affect their ability to damage cells; whether they can act as “Trojan horses” and carry more toxic materials into the body; and what is known about what happens when they get out into the environment.

Risk and the roles that scientists play

Andrew makes his point and holds various groups to account (from his March 29, 2016 article; Note: Links have been removed),

… in the case of Vantablack S-VIS, there’s been a conspicuous absence of such nanotechnology safety experts in media coverage.

This lack of engagement isn’t too surprising – publicly commenting on emerging topics is something we rarely train, or even encourage, our scientists to do.

And yet, where technologies are being commercialized at the same time their safety is being researched, there’s a need for clear lines of communication between scientists, users, journalists and other influencers. Otherwise, how else are people to know what questions they should be asking, and where the answers might lie?

In 2008, initiatives existed such as those at the Center for Biological and Environmental Nanotechnology (CBEN) at Rice University and the Project on Emerging Nanotechnologies (PEN) at the Woodrow Wilson International Center for Scholars (where I served as science advisor) that took this role seriously. These and similar programs worked closely with journalists and others to ensure an informed public dialogue around the safe, responsible and beneficial uses of nanotechnology.

In 2016, there are no comparable programs, to my knowledge – both CBEN and PEN came to the end of their funding some years ago.

Some of the onus here lies with scientists themselves to make appropriate connections with developers, consumers and others. But to do this, they need the support of the institutions they work in, as well as the organizations who fund them. This is not a new idea – there is of course a long and ongoing debate about how to ensure academic research can benefit ordinary people.

Media and risk

As mainstream media such as newspapers and broadcast news continue to suffer losses in audience numbers, the situation vis à vis science journalism has changed considerably since 2008. Finding information is more of a challenge even for the interested.

As for those who might be interested, the chances of catching their attention are considerably more challenging. For example, some years ago scientists claimed to have achieved ‘cold fusion’ and there were television interviews (on the 60 minutes tv programme, amongst others) and cover stories in Time magazine and Newsweek magazine, which you could find in the grocery checkout line. You didn’t have to look for it. In fact, it was difficult to avoid the story. Sadly, the scientists had oversold and misrepresented their findings and that too was extensively covered in mainstream media. The news cycle went on for months. Something similar happened in 2010 with ‘arsenic life’. There was much excitement and then it became clear that scientists had overstated and misrepresented their findings. That news cycle was completed within three or fewer weeks and most members of the public were unaware. Media saturation is no longer what it used to be.

Innovative outreach needs to be part of the discussion and perhaps the Vantablack S-VIS controversy amongst artists can be viewed through that lens.

Anish Kapoor and his exclusive rights to Vantablack

According to a Feb. 29, 2016 article by Henri Neuendorf for artnet news, there is some consternation regarding internationally known artist, Anish Kapoor and a deal he has made with Surrey Nanosystems, the makers of Vantablack in all its iterations (Note: Links have been removed),

Anish Kapoor provoked the fury of fellow artists by acquiring the exclusive rights to the blackest black in the world.

The Indian-born British artist has been working and experimenting with the “super black” paint since 2014 and has recently acquired exclusive rights to the pigment according to reports by the Daily Mail.

The artist clearly knows the value of this innovation for his work. “I’ve been working in this area for the last 30 years or so with all kinds of materials but conventional materials, and here’s one that does something completely different,” he said, adding “I’ve always been drawn to rather exotic materials.”

This description from his Wikipedia entry gives some idea of Kapoor’s stature (Note: Links have been removed),

Sir Anish Kapoor, CBE RA (Hindi: अनीश कपूर, Punjabi: ਅਨੀਸ਼ ਕਪੂਰ), (born 12 March 1954) is a British-Indian sculptor. Born in Bombay,[1][2] Kapoor has lived and worked in London since the early 1970s when he moved to study art, first at the Hornsey College of Art and later at the Chelsea School of Art and Design.

He represented Britain in the XLIV Venice Biennale in 1990, when he was awarded the Premio Duemila Prize. In 1991 he received the Turner Prize and in 2002 received the Unilever Commission for the Turbine Hall at Tate Modern. Notable public sculptures include Cloud Gate (colloquially known as “the Bean”) in Chicago’s Millennium Park; Sky Mirror, exhibited at the Rockefeller Center in New York City in 2006 and Kensington Gardens in London in 2010;[3] Temenos, at Middlehaven, Middlesbrough; Leviathan,[4] at the Grand Palais in Paris in 2011; and ArcelorMittal Orbit, commissioned as a permanent artwork for London’s Olympic Park and completed in 2012.[5]

Kapoor received a Knighthood in the 2013 Birthday Honours for services to visual arts. He was awarded an honorary doctorate degree from the University of Oxford in 2014.[6] [7] In 2012 he was awarded Padma Bhushan by Congress led Indian government which is India’s 3rd highest civilian award.[8]

Artists can be cutthroat but they can also be prankish. Take a look at this image of Kapoor and note the blue background,

Artist Anish Kapoor is known for the rich pigments he uses in his work. (Image: Andrew Winning/Reuters)

Artist Anish Kapoor is known for the rich pigments he uses in his work. (Image: Andrew Winning/Reuters)

I don’t know why or when this image (used to illustrate Andrew’s essay) was taken so it may be coincidental but the background for the image brings to mind, Yves Klein and his International Klein Blue (IKB) pigment. From the IKB Wikipedia entry,

L'accord bleu (RE 10), 1960, mixed media piece by Yves Klein featuring IKB pigment on canvas and sponges Jaredzimmerman (WMF) - Foundation Stedelijk Museum Amsterdam Collection

L’accord bleu (RE 10), 1960, mixed media piece by Yves Klein featuring IKB pigment on canvas and sponges Jaredzimmerman (WMF) – Foundation Stedelijk Museum Amsterdam Collection

Here’s more from the IKB Wikipedia entry (Note: Links have been removed),

International Klein Blue (IKB) was developed by Yves Klein in collaboration with Edouard Adam, a Parisian art paint supplier whose shop is still in business on the Boulevard Edgar-Quinet in Montparnasse.[1] The uniqueness of IKB does not derive from the ultramarine pigment, but rather from the matte, synthetic resin binder in which the color is suspended, and which allows the pigment to maintain as much of its original qualities and intensity of color as possible.[citation needed] The synthetic resin used in the binder is a polyvinyl acetate developed and marketed at the time under the name Rhodopas M or M60A by the French pharmaceutical company Rhône-Poulenc.[2] Adam still sells the binder under the name “Médium Adam 25.”[1]

In May 1960, Klein deposited a Soleau envelope, registering the paint formula under the name International Klein Blue (IKB) at the Institut national de la propriété industrielle (INPI),[3] but he never patented IKB. Only valid under French law, a soleau enveloppe registers the date of invention, according to the depositor, prior to any legal patent application. The copy held by the INPI was destroyed in 1965. Klein’s own copy, which the INPI returned to him duly stamped is still extant.[4]

In short, it’s not the first time an artist has ‘owned’ a colour. Kapoor is not a performance artist as was Klein but his sculptural work lends itself to spectacle and to stimulating public discourse. As to whether or not, this is a prank, I cannot say but it has stimulated a discourse which ranges from intellectual property and artists to the risks of carbon nanotubes and the role scientists could play in the discourse about the risks associated with emerging technologies.

Regardless of how is was intended, bravo to Kapoor.

More reading

Andrew’s March 29, 2016 article has also been reproduced on Nanowerk and Slate.

Johathan Jones has written about Kapoor and the Vantablack  controversy in a Feb. 29, 2016 article for The Guardian titled: Can an artist ever really own a colour?

Inhaling buckyballs (C60 fullerenes)

Carbon nanotubes (also known as buckytubes) have attracted most of the attention where carbon nanomaterials and health and safety are concerned. But, University of Michigan researchers opted for a change of pace and focused their health and safety research on buckyballs (also known as C60 or fullerenes) according to a Feb. 24, 2016 news item on Nanowerk,

Scientists at the University of Michigan have found evidence that some carbon nanomaterials can enter into immune cell membranes, seemingly going undetected by the cell’s built-in mechanisms for engulfing and disposing of foreign material, and then escape through some unidentified pathway. [emphasis mine]

The researchers from the School of Public Health and College of Engineering say their findings of a more passive entry of the materials into cells is the first research to show that the normal process of endocytosis-phagocytosis isn’t always activated when cells are confronted with tiny Carbon 60 (C60 ) molecules.

A Feb. 23, 2016 University of Michigan news release (also on EurekAlert but dated Feb. 24, 2016), which originated the news item, provides more detail about the research,

… This study examined nanomaterials known as carbon fullerenes, in this case C60, which has a distinct spherical shape.

Over the last decade, scientists have found these carbon-based materials useful in a number of commercial products, including drugs, medical devices, cosmetics, lubricants, antimicrobial agents and more. Fullerenes also are produced in nature through events like volcanic eruptions and wildfires.

The concern is that however exposed, commercially or naturally, little is known about how inhaling these materials impacts health.

“It’s entirely possible that even tiny amounts of some nanomaterials could cause altered cellular signaling,” said Martin Philbert, dean and professor of toxicology at the U-M School of Public Health.

Philbert said much of the previously published research bombarded cells with large amounts of particle clusters, unlike a normal environmental exposure.

The U-M researchers examined various mechanisms of cell entry through a combination of classical biological, biophysical and newer computational techniques, using models developed by a team led by Angela Violi to determine how C60 molecules find their way into living immune cells of mice.

They found that the C60 particles in low concentrations were entering the membrane individually, without perturbing the structure of the cell enough to trigger its normal response.

“Computational modeling of C60 interacting with lipid bilayers, representative of the cellular membrane, show that particles readily diffuse into biological membranes and find a thermodynamically stable equilibrium in an eccentric position within the bilayer,” said Violi, U-M professor of mechanical engineering, chemical engineering, biomedical engineering, and macromolecular science and engineering.

“The surprising contribution of passive modes of cellular entry provides new avenues for toxicological research, as we still don’t know exactly what are the mechanisms that cause this crossing.”

So, while the buckyballs enter cells, they also escape from them somehow. I wonder if the mechanisms that allow them to enter the cells are similar to the ones that allow them to escape. Regardless, here’s a link to and a citation for the paper,

C60 fullerene localization and membrane interactions in RAW 264.7 immortalized mouse macrophages by K. A. Russ, P. Elvati, T. L. Parsonage, A. Dews, J. A. Jarvis, M. Ray, B. Schneider, P. J. S. Smith, P. T. F. Williamson, A. Violi and M. A. Philbert. Nanoscale, 2016, 8, 4134-4144 DOI: 10.1039/C5NR07003A First published online 25 Jan 2016

This paper is behind a paywall.

Hypersensitivity to nanomedicine: the CARPA reaction

There is some intriguing research (although I do have a reservation) into some unexpected side effects that nanomedicine may have according to a Feb. 23, 2016 news item on phys.org,

Keywords such as nano-, personalized-, or targeted medicine sound like bright future. What most people do not know, is that nanomedicines can cause severe undesired effects for actually being too big! Those modern medicines easily achieve the size of viruses which the body potentially recognizes as foreign starting to defend itself against —a sometimes severe immune response unfolds.

The CARPA-phenomenon (Complement Activation-Related PseudoAllergy) is a frequent hypersensitivity response to nanomedicine application. Up to 100 patients worldwide suffer from severe reactions, such as cardiac distress, difficulty of breathing, chest and back pain or fainting each day when their blood gets exposed to certain nanoparticles during medical treatment. Every 10 days one patient even dies due to an uncontrollable anaphylactoid reaction.

Apart from being activated in a different way, this pseudoallergy has the same symptoms as a common allergy, bearing a crucial difference:  the reaction is taking place without previous sensitizing exposure to a substance, making it hard to predict, whether a person will react to a specific nanodrug or be safe. Intrigued by this vital challenge, János Szebeni from Semmelweis University, Budapest, has been working with scientific verve on the decipherment and prevention of the CARPA phenomenon for more than 20 years. With his invaluable support De Gruyter´s European Journal of Nanomedicine (EJNM) lately dedicated an elaborate compilation of the most recent scientific advances on CARPA, presented by renowned experts on the subject.

A Feb. 23, 2016 De Gruyter Publishers press release, which originated the news item, provides more detail,

Interestingly it´s pigs that turned out to serve as best model for research on the complex pathomechanism, diagnosis and potential treatment of CARPA. “Pigs´ sensitivity equals that of humans responding most vehemently to reactogenic nanomedicines”, Szebeni states.  In a contribution to EJNM´s compilation on CARPA, Rudolf Urbanics and colleagues show that reactions to specific nanodrugs are even quantitatively reproducible in pigs … . Szebeni: “This is absolutely rare in allergy-research. In these animals the endpoint of the overreaction is reflected in a rise of pulmonary arterial pressure, being as accurate as a Swiss watch”. Pigs can thus be used for drug screening and prediction of the CARPAgenic potential of nanomedicines. This becomes increasingly important with the ever growing interest in modern drugs requiring reliable preclinical safety assays during the translation process from bench to bedside. Results might also help to personalize nanomedicine administration schedules during for example the targeted treatment of cancer. The same holds true for a very recently developed in vitro immunoassay. By simply using a patient´s blood sample, it tests for potential CARPA reactions even before application of specific nanodrugs.

Here’s a link to and a citation for the paper,

Lessons learned from the porcine CARPA model: constant and variable responses to different nanomedicines and administration protocols by Rudolf Urbanics, Péter Bedőcs, János Szebeni. European Journal of Nanomedicine. Volume 7, Issue 3, Pages 219–231, ISSN (Online) 1662-596X, ISSN (Print) 1662-5986, DOI: 10.1515/ejnm-2015-0011, June 2015

This paper appears to be open access.

As for reservations, I’m not sure what occasioned the news release so many months post publication of the paperand it should be noted that János Szebeni seems to be the paper’s lead author and the editor of the European Journal of Nanomedicine.

Short term exposure to engineered nanoparticles used for semiconductors not too risky?

Short term exposure means anywhere from 30 minutes to 48 hours according to the news release and the concentration is much higher than would be expected in current real life conditions. Still, this research from the University of Arizona and collaborators represents an addition to the data about engineered nanoparticles (ENP) and their possible impact on health and safety. From a Feb. 22, 2016 news item on phys.org,

Short-term exposure to engineered nanoparticles used in semiconductor manufacturing poses little risk to people or the environment, according to a widely read research paper from a University of Arizona-led research team.

Co-authored by 27 researchers from eight U.S. universities, the article, “Physical, chemical and in vitro toxicological characterization of nanoparticles in chemical mechanical planarization suspensions used in the semiconductor industry: towards environmental health and safety assessments,” was published in the Royal Society of Chemistry journal Environmental Science Nano in May 2015. The paper, which calls for further analysis of potential toxicity for longer exposure periods, was one of the journal’s 10 most downloaded papers in 2015.

A Feb. 17, 2016 University of Arizona news release (also on EurekAlert), which originated the news item, provides more detail,

“This study is extremely relevant both for industry and for the public,” said Reyes Sierra, lead researcher of the study and professor of chemical and environmental engineering at the University of Arizona.

Small Wonder

Engineered nanoparticles are used to make semiconductors, solar panels, satellites, food packaging, food additives, batteries, baseball bats, cosmetics, sunscreen and countless other products. They also hold great promise for biomedical applications, such as cancer drug delivery systems.

Designing and studying nano-scale materials is no small feat. Most university researchers produce them in the laboratory to approximate those used in industry. But for this study, Cabot Microelectronics provided slurries of engineered nanoparticles to the researchers.

“Minus a few proprietary ingredients, our slurries were exactly the same as those used by companies like Intel and IBM,” Sierra said. Both companies collaborated on the study.

The engineers analyzed the physical, chemical and biological attributes of four metal oxide nanomaterials — ceria, alumina, and two forms of silica — commonly used in chemical mechanical planarization slurries for making semiconductors.

Clean Manufacturing

Chemical mechanical planarization is the process used to etch and polish silicon wafers to be smooth and flat so the hundreds of silicon chips attached to their surfaces will produce properly functioning circuits. Even the most infinitesimal scratch on a wafer can wreak havoc on the circuitry.

When their work is done, engineered nanoparticles are released to wastewater treatment facilities. Engineered nanoparticles are not regulated, and their prevalence in the environment is poorly understood [emphasis mine].

Researchers at the UA and around the world are studying the potential effects of these tiny and complex materials on human health and the environment.

“One of the few things we know for sure about engineered nanoparticles is that they behave very differently than other materials,” Sierra said. “For example, they have much greater surface area relative to their volume, which can make them more reactive. We don’t know whether this greater reactivity translates to enhanced toxicity.”

The researchers exposed the four nanoparticles, suspended in separate slurries, to adenocarcinoma human alveolar basal epithelial cells at doses up to 2,000 milligrams per liter for 24 to 38 hours, and to marine bacteria cells, Aliivibrio fischeri, up to 1,300 milligrams per liter for approximately 30 minutes.

These concentrations are much higher than would be expected in the environment, Sierra said.

Using a variety of techniques, including toxicity bioassays, electron microscopy, mass spectrometry and laser scattering, to measure such factors as particle size, surface area and particle composition, the researchers determined that all four nanoparticles posed low risk to the human and bacterial cells.

“These nanoparticles showed no adverse effects on the human cells or the bacteria, even at very high concentrations,” Sierra said. “The cells showed the very same behavior as cells that were not exposed to nanoparticles.”

The authors recommended further studies to characterize potential adverse effects at longer exposures and higher concentrations.

“Think of a fish in a stream where wastewater containing nanoparticles is discharged,” Sierra said. “Exposure to the nanoparticles could be for much longer.”

Here’s a link to and a citation for the paper,

Physical, chemical, and in vitro toxicological characterization of nanoparticles in chemical mechanical planarization suspensions used in the semiconductor industry: towards environmental health and safety assessments by David Speed, Paul Westerhoff, Reyes Sierra-Alvarez, Rockford Draper, Paul Pantano, Shyam Aravamudhan, Kai Loon Chen, Kiril Hristovski, Pierre Herckes, Xiangyu Bi, Yu Yang, Chao Zeng, Lila Otero-Gonzalez, Carole Mikoryak, Blake A. Wilson, Karshak Kosaraju, Mubin Tarannum, Steven Crawford, Peng Yi, Xitong Liu, S. V. Babu, Mansour Moinpour, James Ranville, Manuel Montano, Charlie Corredor, Jonathan Posner, and Farhang Shadman. Environ. Sci.: Nano, 2015,2, 227-244 DOI: 10.1039/C5EN00046G First published online 14 May 2015

This is open access but you may need to register before reading the paper.

The bit about nanoparticles’ “… prevalence in the environment is poorly understood …”and the focus of this research reminded me of an April 2014 announcement (my April 8, 2014 posting; scroll down about 40% of the way) regarding a new research network being hosted by Arizona State University, the LCnano network, which is part of the Life Cycle of Nanomaterials project being funded by the US National Science Foundation. The network’s (LCnano) director is Paul Westerhoff who is also one of this report’s authors.