Tag Archives: asbestos

Gold nanotubes for treating mesothelioma?

An October 26, 2020 news item on Nanowerk describes some new research that may lead the way to treatments for people with asbestos-related cancers (e.g., mesothelioma), Note: A link has been removed,

Gold nanotubes – tiny hollow cylinders one thousandth the width of a human hair – could be used to treat mesothelioma, a type of cancer caused by exposure to asbestos, according to a team of researchers at the Universities of Cambridge and Leeds.
In a study published in journal Small (“Exploring High Aspect Ratio Gold Nanotubes as Cytosolic Agents: Structural Engineering and Uptake into Mesothelioma Cells”), the researchers demonstrate that once inside the cancer cells, the nanotubes absorb light, causing them to heat up, thereby killing the cells.
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Here`s an image illustrating the research,

Caption: Confocal fluorescence image of gold nanotures (green) in mesothelioma cells. Credit: Arsalan Azad

An October 27, 2020 University of Cambridge press release (also on EurekAlert but published on Oct. 26, 2020), which originated the news item, describes the context for the research and provides a few more technical details,

More than 2,600 people are diagnosed in the UK each year with mesothelioma, a malignant form of cancer caused by exposure to asbestos. Although the use of asbestos is outlawed in the UK now, the country has the world’s highest levels of mesothelioma because it imported vast amounts of asbestos in the post-war years. The global usage of asbestos remains high, particularly in low- and middle-income countries, which means mesothelioma will become a global problem.
“Mesothelioma is one of the ‘hard-to-treat’ cancers, and the best we can offer people with existing treatments is a few months of extra survival,” said Dr Arsalan Azad from the Cambridge Institute for Medical Research at the University of Cambridge. “There’s an important unmet need for new, effective treatments.”
In 2018, the University of Cambridge was awarded £10million from the Engineering and Physical Sciences Research Council to help develop engineering solutions, including nanotech, to find ways to address hard-to-treat cancers.
In a collaboration between the University of Cambridge and University of Leeds, researchers have developed a form of gold nanotubes whose physical properties are ‘tunable’ – in other words, the team can tailor the wall thickness, microstructure, composition, and ability to absorb particular wavelengths of light.
The researchers added the nanotubes to mesothelioma cells cultured in the lab and found that they were absorbed by the cells, residing close to the nucleus, where the cell’s DNA lies. When the team targeted the cells with a laser, the nanotubes absorbed the light and heated up, killing the mesothelioma cell.
Professor Stefan Marciniak, also from the Cambridge Institute for Medical Research, added: “The mesothelioma cells ‘eat’ the nanotubes, leaving them susceptible when we shine light on them. Laser light is able to penetrate deep into tissue without causing damage to surrounding tissue. It then gets absorbed by the nanotubes, which heat up and, we hope in the future, could be used to cause localised cancer-cell killing.”
The team will be developing the work further to ensure the nanotubes are targeted to cancer cells with less effect on normal tissue.
The nanotubes are made in a two-step process. First, solid silver nanorods are created of the desired diameter. Gold is then deposited from solution onto the surface of the silver. As the gold builds-up at the surface, the silver dissolves from the inside to leave a hollow nanotube.
The approach advanced by the Leeds team allows these nanotubes to be developed at room temperature, which should make their manufacture at scale more feasible.
Professor Stephen Evans from the School of Physics and Astronomy at the University of Leeds said: “Having control over the size and shape of the nanotubes allows us to tune them to absorb light where the tissue is transparent and will allow them to be used for both the imaging and treatment of cancers. The next stage will be to load these nanotubes with medicines for enhanced therapies.”

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

Exploring High Aspect Ratio Gold Nanotubes as Cytosolic Agents: Structural Engineering and Uptake into Mesothelioma Cells by Sunjie Ye, Arsalan A. Azad, Joseph E. Chambers, Alison J. Beckett, Lucien Roach, Samuel C. T. Moorcroft, Zabeada Aslam, Ian A. Prior, Alexander F. Markham, P. Louise Coletta, Stefan J. Marciniak, Stephen D. Evans. Small DOI: https://doi.org/10.1002/smll.202003793 First published: 25 October 2020

This paper is open access.

Futurography’s nanotechnology series: a digest

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There’s a series of Slate.com articles, under their Future Tense: The Citizen’s Guide to the Future and Futurography programmes, which are the result of a joint partnership between Slate, New America, and Arizona State University (ASU). For the month of Sept. 2016, the topic was nanotechnology.

Introductory articles

Jacob Brogan kicked off the series with his Sept. 6, 2016 article, What the Heck is Nanotech?,

So I know nanotech is both really tiny and a really big deal.

Thanks for getting that joke out of the way.

But also my eyes glaze over whenever someone starts to talk about graphene or nanotubes. What is nanotech, exactly? And should I care?

In the broadest sense, nanotech refers to the deliberate manipulation of matter on an atomic scale. That means it’s arguably as old as our understanding of atoms themselves. To listen to nanoevangelists, the technology could radically transform our experience of material culture, allowing us to assemble anything and everything—food, clothing, and so on—from raw atomic building blocks. That’s a bit fantastical, of course, but even skeptics would admit that nanotech has enabled some cool advances.

Actual conversations around the technology have been building since at least the late 1950s, when famed physicist Richard Feynman gave a seminal talk titled “There’s Plenty of Room at the Bottom,” in which he laid out the promise of submolecular engineering. In that presentation—and a 1984 follow-up of the same name—Feynman argued that working at the nanoscale would give us tremendous freedom. If we could manipulate atoms properly, he suggested, we could theoretically “write the entire 24 volumes of the Encyclopaedia Brittanica on the head of a pin.”

In that sense, Feynman was literally talking about available space, but what really makes nanotechnology promising is that atomic material sometimes behaves differently at that infinitesimal scale. At that point, quantum effects and other properties start to come into play, allowing us to employ individual atoms in unusual ways. For example, silver particles have antibacterial qualities, allowing them to be employed in washing machines and other appliances. Much of the real practice of nanotech today is focused on exploring these properties, and it’s had a very real impact in all sorts of material science endeavors. The most exciting stuff is still ahead: Engineers believe that single-atom-thick sheets of carbon—the graphene stuff you didn’t want to talk about—might have applications in everything from water purification to electronics fabrication.

You say this stuff is small. How small, exactly?

So small! As the National Nanotechnology Initiative explains, “In the International System of Units, the prefix ‘nano’ means one-billionth, or 10-9; therefore one nanometer is one-billionth of a meter.” To put that into perspective, the NNI notes that a human hair follicle can reach a thickness of 100,000 nanometers. To work at this scale is to work far, far beyond the capacities of the naked eye—and well outside those of conventional microscopes.

Can we even see these things, then?

As it happens, we can, thanks in large part to the development of scanning tunneling microscopes, which allow researchers to create images with resolutions of less than a nanometer. Significantly, these machines can also allow their users to manipulate atoms, which famously enabled the IBM-affiliated physicists Don Eigler and Erhard K. Schweizer to write his company’s logo with 35 individual xenon atoms in 1989.

What I do know about nanotech is that it involves something called gray goo. Gross.

Gray goo is the nanorobot-takeover scenario of the nanotech world. Here’s the gist: Feynman proposed that we could build an ever-smaller series of telepresence tools. The idea is that you make a small, remotely controlled machine that then allows you to make an even smaller machine, and so on until you get all the way down to the nanoscale. By the time you’re at that level, you have machines that are literally moving atoms around and assembling them into other tiny robots.

Feynman treated this as little more than an exciting thought experiment, but others—most notably, perhaps, engineer K. Eric Drexler—took it quite seriously. In his 1986 book Engines of Creation, Drexler proposed that we might be able to do more than build machines capable of manipulating atomic material—autonomous and self-replicating machines that could do all of this work without human intervention. But Drexler also warned that poorly controlled atomic replicators could lead to what he called the “gray goo problem,” in which those tiny machines start to re-create everything in their own image, eradicating all organic life in their path.

Drexler, in other words, helped spark both enthusiasm about the promise of nanotech and popular panic about its risks. Both are probably outsized, relative to the scale at which we’re really working here.

It’s been, like, 30 years since Drexler wrote that book. Do we actually have tiny self-replicating machines yet?

No.

Will we?

Probably not anytime soon, no. And maybe never: In a 2001 Scientific American article, the Nobel Prize–winning scientist Richard E. Smalley articulated something he named the “fat fingers problem”: It would be impracticably difficult to create a machine capable of manipulating individual atoms, since the hypothetical robot would need multiple limbs in order to do its work. The systems controlling those limbs would be larger still, till you get to the point where working at the nanoscale is impractical. Winking back at Feynman, Smalley quipped, “there’s not that much room.”

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It’s a pretty good overview although there are some curious omissions. Unfortunately, Brogan never does reveal his interview subject’s name. Also, I’m surprised the interviewee left out Norio Taniguchi, a Japanese engineer who in 1974 coined the term ‘nanotechnology’ and Gerd Binnig and Heinrich Rohrer, the IBM scientists in Switzerland who invented the scanning tunneling microscope which made Eigler’s and Schweizer’s achievement possible. As for Richard Feynman and his ‘seminal’ 1959 lecture, that is up for debate according to cultural anthropologist Chris Toumey. From a 2009 Nature Nanotechnology editorial (Nature Nanotechnology 4, 781 [2009] doi:10.1038/nnano.2009.356) Note: Links have been removed,

Chris Toumey has probably done more than anyone to analyse the true impact of ‘Plenty of room’ on the development of nanotechnology by revealing, among other things, that it was only cited seven times in the first two decades after it was first published in the Caltech magazine Engineering and Science in 1960 (ref. 5). However, as nanotechnology emerged as a major area of research following the invention of the scanning tunnelling microscope in 1981, and culminating in the famous IBM paper of 1991, “it needed an authoritative account of its origin,” writes Toumey on page 783. “Pointing back to Feynman’s lecture would give nanotechnology an early date of birth and it would connect nanotechnology to the genius, the personality and the eloquence of Richard P. Feynman.”

Brogan has also produced a ‘cheat-sheet’ in a Sept. 6, 2016 article (A Cheat-Sheet Guide to Nanotechnology) for Slate. It’s a bit problematic. Apparently the only key players worth mentioning are from the US (Angela Belcher, K. Eric Drexler, Don Eigler, Michelle Y. Simmons, Richard Smalley, and Lloyd Whitman. Even using the US as one’s only base for key players, quite a few people have been left out (Chad Mirkin, Mildred Dresselhaus, Mihail [Mike] Rocco, Robert Langer, Omid Farokhzad, John Rogers, and many other US and US-based researchers).

The glossary (or lingo as it’s termed in the article) is also problematic (from the cheat-sheet),

Carbon nanotubes: These extremely strong structures made from sheets of rolled graphene have been used in everything from bicycle components to industrial epoxies.

Unless you happen to know what graphene is, the definition isn’t that helpful. Basically, the cheat-sheet provides an introduction including some pop culture references but you will need to dig deeper if you want to have a reasonable grasp of the terminology and of the field.

Nanomedicine

James Pitt’s Sept. 15, 2016 article, Nanoparticles vs. Cancer, takes some unexpected turns (it’s not all about nanomedicine), Note: Links have been removed,

Nanoparticles’ size makes them particularly useful against foes such as cancer. Unlike normal blood vessels that branch smoothly and flow in the same direction, blood vessels in tumors are a disorderly mess. And just as grime builds up in bad plumbing, nanoparticles, it seems, can be designed to build up in these problem growths.

This quirk of tumors has led to a bewildering number of nanotech-related schemes to kill cancer. The classic approach involves stapling drugs to nanoparticles that ensure delivery to tumors but not to healthy parts of the body. A wilder method involves things like using a special kind of nanoparticle that absorbs infrared light. Shine a laser through the skin on the build-up, and the particles will heat up to fry the tumor from the inside out.

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Take nanotubes, tiny superstrong cylinders. Remember using lasers to cook tumors? That involves nanotubes. Researchers also want to use nanotubes to regrow broken bones and connect brains with computers. Although they hold a lot of promise, certain kinds of long carbon nanotubes are the same size and shape as asbestos. Both are fibers thin enough to pierce deep inside the lungs but too long for the immune system to engulf and destroy. Mouse experiments have already suggested that inhaling these nanotubes causes the same harmful effects (such as a particularly deadly form of cancer) as the toxic mineral once widely used in building insulation.

Shorter nanotubes, however, don’t seem to be dangerous. Nanoparticles can be built in all sorts of different ways, and it’s difficult to predict which ones will go bad. Imagine if houses with three bathrooms gave everyone in them lung disease, while houses with two or four bathrooms were safe. It gets to the central difficulty of these nanoscale creations—the unforeseen dangers that could be the difference between biomiracle and bioterror.

Up to this point, Pitt has been, more or less, on topic but then there’s this,

Enter machine learning, that big shiny promise to solve all of our complicated problems. The field holds a lot of potential when it comes to handling questions where there are many possible right answers. Scientists often take inspiration from nature—evolution, ant swarms, even our own brains—to teach machines the rules for making predictions and producing outcomes without explicitly giving them step-by-step programming. Given the right inputs and guidelines, machines can be as good or even better than we are at recognizing and acting on patterns and can do so even faster and on a larger scale than humans alone are capable of pulling off.

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Here’s how it works. You put different kinds of nanoparticles in with cells and run dozens of experiments changing up variables such as particle lengths, materials, electrical properties, and so on. This gives you a training set.

Then you let your machine-learning algorithm loose to learn from the training set. After a few minutes of computation, it builds a model of what mattered. From there comes the nerve-wracking part; you give the machine a test set—data similar to but separate from your training set—and see how it does.

Pitt has put something interesting together but I think it’s a bit choppy.

Nano and artists

Emily Tamkin in a Sept. 20, 2016 article talks with artist Kate Nichols about her experiences with nanotechnology (Note: Links have been removed),

Kate Nichols is doing something very new—and very old.

The former painter’s apprentice is the first artist-in-residence at the Alivisatos Lab, a nanoscience laboratory at UC [University of California]–Berkeley. She’s made art out of silver nanoparticles, compared Victorian mirror-making technology with today’s nanotechnology, and has grown cellulose from bacteria. Her newest project explores mimesis, or lifelike replication, in both 15th-century paintings and synthetic biology. That work may seem dazzlingly high-tech, but she says it’s in keeping with the most ancient of artistic traditions: creating something new by making materials out of the world around.

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How did you move from that [being a painter’s apprentice] to using nanomaterials in your art?

It was sort of an organic process that began years before I started working with these materials. It was inspired by two things. One was, I’ve always been intrigued by artists who made their own materials. Going back to early cave painters—the practice of making art didn’t begin with making images, but with selecting and modifying and refining the materials to make art with. When I was studying these Renaissance-era methods of making paint—practicing with these methods, making my own paints in my studio—I began thinking that in many ways, it was sort of like a historical re-enactment. I was using these methods that were developed by these people back in the 1400s. As a person who’s interested in this tradition of painting, what does it mean to be building on that tradition in the 2000s? So I was thinking, well, it seems like the next step would be to develop my own materials that speak to me in my time, with things that they didn’t have access to then.

The second is that back in college, I had to take some sort of quantitative class. I took a math class that I was really fascinated by—modeling biological growth and form. It was taught by a mathematician at Kenyon named Judy Holdener, and Judy studied art before she switched to math. We ended up doing independent study together, and she taught me about the morpho butterfly, which is sort of a poster child for structural color. Having been a painter’s apprentice, I sort of fancied myself a young expert in color. But encountering this butterfly made me realize I had so much more to learn. Color can be generated in other ways than pigmentation. But to create structural color you had to operate on such a small scale. It seemed impossible. But as the years went on I started hearing feature stories about nanotechnology. And I realized these are the people who can create things that small. And that’s how I got the idea.

This article is about one of me favourite topics which is art/science and, happily, it’s a good read. (For anyone interested in her earlier work with colour and blue morpho butterflies, there’s this Feb. 12, 2010 posting.

Before heading off to the next topic, here’s one of Nichols’ images,

Visible Signs of Indeterminate Meaning 14, silver nanoparticle paint and silver mirroring on glass, 12 by 15.5 inches, 2015. These small works on glass are created with silver nanoparticles that Nichols synthesizes and with Victorian-era silver mirroring techniques. Visible Signs of Indeterminate Meaning is the product of carefully planned measurements, calculations, and titrations in a chemistry lab and of spontaneous smears, spills, and erasures in the artist’s painting studio. Credit: Donald Felton [downloaded from http://www.slate.com/articles/technology/future_tense/2016/09/an_interview_with_kate_nichols_artist_in_residence_at_alivisatos_lab.html]

Nano definitions

Gary Machant’s Sept. 22, 2016 piece about nanomaterial definitions is well written but it’s for an audience who for one reason or another is interested in policy and regulation (Note: Links have been removed),

Consider two recent attempts. Exhibit A is the definition of nanotechnology adopted by the European Union. After much deliberation and struggle, in 2011 the European Commission, which aimed to adopt a “science-based” definition, came up with the following:

A natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50% or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm [nanometer] – 100 nm. In specific cases and where warranted by concerns for the environment, health, safety or competitiveness the number size distribution threshold of 50% may be replaced by a threshold between 1 and 50%.

Exhibit B is the U.S. Environmental Protection Agency’s proposed definition of nanomaterials. The regulatory body is scheduled to finalize rules this fall requiring companies that produce or handle nanomaterials to report certain information about such substances to the agency:

[A] chemical substance that is solid at 25 °C and atmospheric pressure that is manufactured or processed in a form where the primary particles, aggregates, or agglomerates are in the size range of 1–100 nm and exhibit unique and novel characteristics or properties because of their size. A reportable chemical substance does not include a chemical substance that only has trace amounts of primary particles, aggregates, or agglomerates in the size range of 1–100 nm, such that the chemical substance does not exhibit the unique and novel characteristics or properties because of particle size.

See the differences? The EPA definition only includes manufactured nanomaterials, but the EU definition includes manufactured, natural, and incidental ones. On the other hand, the EPA defines materials by size (1–100nm) and requires that they exhibit some novel property (like catalytic activity, chemical reactivity, or electric conductivity), while the EU just looks at size. And it goes on with differences in composition requirements, aggregate thresholds, and other characteristics.

These are just two of more than two dozen regulatory definitions of nanotechnology, all differing in important ways: size limits, dimensions (do we regulate in 1-D, 2-D, or 3-D?), properties, etc. These differences can have major practical significance—for example, some commercially important materials (e.g., graphite sheets) may be nanosize in one or two dimensions but not three. The conflicting definitions create confusion and inefficiencies for consumers, companies, and researchers when some substances are defined as nanomaterials under certain programs or nations but not others.

I recommend it if you want a good sense of the nanomaterial policy and regulatory environment.

Nano fatigue

This Sept. 27, 2016 piece by Dr. Andrew Maynard is written in a lightly humourous fashion by someone who’s been working in the nanotechnology field for decades. I have to confess to some embarrassment as I sometimes feel much the same way (“nano’d out”) and I haven’t been at it nearly as long (Note: Links have been removed),

Writing about nanotechnology used to be fun. Now? Not so much. I am, not to put too fine a point on it, nano’d out. And casual conversations with my colleagues suggest I’m not alone: Many of us who’ve been working in the field for more years than we care to remember have become fatigued by a seemingly never-ending cycle of nano-enthusiasm, analysis, critique, despondency, and yet more enthusiasm.

For me, this weariness is partly rooted in a frustration that we’re caught up in a mythology around nanotechnology that is not only disconnected from reality but is regurgitated with Sisyphean regularity. And yet, despite all my fatigue and frustration, I still think we need to talk nano. Just not in the ways we’ve done so in the past.

To explain this, let me go back in time a little. I was first introduced to the nanoscale world in the 1980s as an undergraduate studying physics in the United Kingdom. My entrée wasn’t Eric Drexler’s 1986 work Engines of Creation—which introduced the idea of atom-by-atom manufacturing to many people, and which I didn’t come across until some years later. Instead, for me, it was the then-maturing field of materials science.

This field drew on research in physics and chemistry that extended back to the early 1900s and the development of modern atomic theory. It used emerging science to better understand and predict how the atomic-scale structure of materials affected their physical and chemical behavior. In my classes, I learned about how microscopic features in materials influenced their macroscopic properties. (For example, “microcracks” influence glass’s macro properties like its propensity to shatter, and atomic dislocations affect the hardness of metals.) I also learned how, by creating well-defined nanostructures, we could start to make practical use of some of the more unusual properties of atoms and electrons.

A few years later, in 1989, I was studying environmental nanoparticles as part of my Ph.D. at the University of Cambridge. I was working with colleagues who were engineering nanoparticles to make more effective catalysts. (That is, materials that can help chemical reactions go faster or more efficiently—like the catalysts in vehicle tailpipes.) At the time virtually no one was talking about “nanotechnology.” Yet a lot of people were engaged in what would now be considered nanoscale science and engineering.

Fast forward to the end of the 1990s. Despite nearly a century of research into matter down at the level of individual atoms and molecules, funding agencies suddenly “discovered” nanotechnology. And in doing so, they fundamentally changed the narrative around nanoscale science and engineering. Nanoscale science and engineering (and the various disciplines that contributed to it) were rebranded as “nanotechnology”: a new frontier of discovery, the “next industrial revolution,” an engine of economic growth and job creation, a technology that could do everything from eliminate fossil fuels to cure cancer.

From the perspective of researchers looking for the next grant, nanotechnology became, in the words of one colleague, “a 14-letter fast-track to funding.” Almost overnight, it seemed, chemists, physicists, and materials scientists—even researchers in the biological sciences—became “nanotechnologists.” At least in public. Even these days, I talk to scientists who will privately admit that, to them, nanotechnology is simply a convenient label for what they’ve been doing for years.

The problem was, we were being buoyed along by what is essentially a brand—an idea designed to sell a research agenda.

This wasn’t necessarily a bad thing. Investment in nanotechnology has led to amazing discoveries and the creation of transformative new products. (Case in point: Pretty much every aspect of the digital world we all now depend on relies on nano-engineered devices.) It’s also energized new approaches to science engagement and education. And it’s transformed how we do interdisciplinary research.

But “brand nanotechnology” has also created its own problems. There’s been a constant push to demonstrate its newness, uniqueness, and value; to justify substantial public and private investment in it; and to convince consumers and others of its importance.

This has spilled over into a remarkably persistent drive to ensure nanotechnology’s safety, which is something that I’ve been deeply involved in for many years now. This makes sense, at least on the surface, as some products of nanotechnology have the potential to cause serious harm if not developed and used responsibly. For instance, it appears that carbon nanotubes can cause lung disease if inhaled, or seemingly benign nanoparticles may end up poisoning ecosystems. Yet as soon as you try to regulate “brand nanotechnology,” or study how toxic “brand nanotechnology” is in mice, or predict the environmental impacts of “brand nanotechnology,” things get weird. You can’t treat a brand as a physical thing.

Because of this obsession with “brand nanotechnology” (which of course is just referred to as “nanotechnology”), we seem to be caught up in an endless cycle of nanohype and nanodiscovery, where the promise of nanotech is always just over the horizon, and where the same nanonarrative is repeated with such regularity that it becomes almost myth-like.

I recommend reading the article in its entirety.

Risks

Korin Wheeler discusses nanomaterials and their possible impact on the environment in his Sept. 29, 2016 article. The introduction is a little leisurely but every word proves relevant to the topic (Note: Links have been removed),

Imagine your future self-driving car. You’ll get so much more work done with extra time in your commute, and without a driver, your commute will be safer. Or will it? During your first ride, you probably won’t be able to shake the fear that the software doesn’t know to avoid pedestrians or that you’ll get a ticket because the car ran a light. New technologies are inherently a tangle of exciting possibilities and new risks. We’ve learned from history—and from dinosaurs escaping Jurassic Park—that potential dangers must be evaluated and mitigated before new technologies are released.

Car crashes and T. rex teeth are obvious hazards, but the risks of nanotechnology can be less accessible. Their small size and surprising properties make them difficult to define, discuss, and evaluate. Yet these are the same properties that make nanotechnology so revolutionary and impactful. Nanotechnology is one of the core ideas behind the science of the driverless car and the science fiction of living, 21st-century dinosaurs. Your future self-driving vehicle will likely contain a catalytic converter made efficient by platinum nanomaterials and a self-cleaning paint made possible by titanium dioxide nanomaterials. If electric, the lithium-ion battery may contain nickel magnesium cobalt oxide, or NMC, nanomaterials. If nanotechnology fulfills its promises to reduce emissions, gas requirements, and water use, we will see quality of human life improve, and environmental impacts reduced. But like all progress, nanotechnologies have inherent risk.

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In evaluating and reducing the environmental risks of nanotechnologies, scientists and engineers are taking a variety of approaches. Studies include two broad classifications of nanomaterials: natural and engineered. Natural nanomaterials have evolved with life on this planet. In our daily lives, they are found in ocean spray, campfire smoke, and even in milk as protein/lipid micelles. It is only in the past few decades, however, that scientists and engineers have been able to accurately make, manipulate, and characterize matter at the atomic scale. These “engineered” nanomaterials designed by scientists and engineers are made for specific applications in well-controlled, reproducible processes. Comparing a naturally occurring and an engineered nanomaterial is like comparing a pebble to a marble. Both are roughly the same size, but they are otherwise very different. Like most anything man-made, engineered nanomaterials are designed with a targeted function and their structure is more uniform, pure, pristine, and well-ordered. These two categories of material can behave and react differently.

Once the nanomaterial is released from manufacturer conditions, it can undergo dramatic changes, including physical, chemical, and biological transformations. As engineered nanomaterials enter the environment, they begin to resemble their natural counterparts. Let’s go back to the example of a marble. If you throw one into a stream, the marble may chip, develop imperfections, and change shape from pounding on rocks. Chemical reactions might strip it of its protective plastic coating. Microorganisms may even be able to take hold to form a new biological surface on the marble. By studying these kinds of complexities and imperfections already present in natural nanomaterials, scientists will be able to predict how these complexities change the behavior and impacts of engineered nanomaterials as well.

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The diversity and novel properties of engineered nanomaterials affect the way they react and change in the environment. Every single engineered nanomaterial requires an environmental impact study designed to include a range of sizes, shapes, impurities, and surface properties. Since many nanomaterials are essentially small particles suspended in solution (known as “colloidal suspensions”), they can dissolve, join together (or “aggregate”), and undergo surface changes. We don’t have to consider these factors when it comes to more “traditional” molecular structures that are dissolved, like aspirin or table salt. Suddenly, an environmental impact study becomes an exponentially greater task

Read the article in its entirety to get a better sense of the complexity of the issues.

Slate ties up the nanotechnology series in a bow

Jacob Brogan writes up “Six myths about nanotechnology” in his Sept. 29, 2016 article,

1. It’s Not Radically New

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2. It’s Not a Unified Area of Inquiry

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3. It’s Not About Any One Tool

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4. It Doesn’t Make Things Simpler—It Complicates Them

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5. It Isn’t Necessarily Dangerous

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6. It’s Still a Useful Term (Probably)

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Quiz

On Sept. 30, 2016, Brogan produced a quiz (10 questions,

This September, Future Tense has been exploring nanotechnology as part of our ongoing project Futurography, which introduces readers to a new technological or scientific topic each month. Now’s your chance to show us how much you’ve learned.

And, at long last and finally, there is a survey (Sept. 30, 2016),

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With that [nanotechnology series] behind us, we’d like to hear about your thoughts. What do you think about these issues? Where should the field go from here? Is nanotechnology as such even a thing?

Come back next month [Oct. 2016] for a roundup of your responses. …

Enjoy!

ETA Oct. 11, 2016: Jacob Brogan has written up the results of the survey in an Oct. 7, 2016 piece for Slate. Briefly, the greatest interest is in medical applications and research into aging. People did not seem overly concerned about negative impacts although they didn’t dismiss the possibilities either. There’s more but for that you need to read Brogan’s piece.

Not enough talk about nano risks?

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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)

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

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?

Inadvertent carbon nanotube production from your car

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It’s disconcerting to find out that cars inadvertently produce carbon nanotubes which are then spilled into the air we breathe. Researchers at Rice University (US) and Paris-Saclay University (France) have examined matter from car exhausts and dust in various parts of Paris finding carbon nanotubes (CNTs). Further, they also studied the lungs of Parisian children who have asthma and found CNTs there too.

The scientists have carefully stated that CNTs have been observed in lung cells but they are not claiming causality (i.e., they don’t claim the children’s asthma was caused by CNTs).

An Oct. 20, 2015 news item on Nanotechnology Now introduces the research,

Cars appear to produce carbon nanotubes, and some of the evidence has been found in human lungs.

Rice University scientists working with colleagues in France have detected the presence of man-made carbon nanotubes in cells extracted from the airways of Parisian children under routine treatment for asthma. Further investigation found similar nanotubes in samples from the exhaust pipes of Paris vehicles and in dust gathered from various places around the city.

The researchers reported in the journal EBioMedicine this month that these samples align with what has been found elsewhere, including Rice’s home city of Houston, in spider webs in India and in ice cores.

An Oct. 19, 2015 Rice University news release (also on EurekAlert), which originated the news item, painstakingly describes the work and initial conclusions,

The research in no way ascribes the children’s conditions to the nanotubes, said Rice chemist Lon Wilson, a corresponding author of the new paper. But the nanotubes’ apparent ubiquity should be the focus of further investigation, he said.

“We know that carbon nanoparticles are found in nature,” Wilson said, noting that round fullerene molecules like those discovered at Rice are commonly produced by volcanoes, forest fires and other combustion of carbon materials. “All you need is a little catalysis to make carbon nanotubes instead of fullerenes.”

A car’s catalytic converter, which turns toxic carbon monoxide into safer emissions, bears at least a passing resemblance to the Rice-invented high-pressure carbon monoxide, or HiPco, process to make carbon nanotubes, he said. “So it is not a big surprise, when you think about it,” Wilson said.

The team led by Wilson, Fathi Moussa of Paris-Saclay University and lead author Jelena Kolosnjaj-Tabi, a graduate student at Paris-Saclay, analyzed particulate matter found in the alveolar macrophage cells (also known as dust cells) that help stop foreign materials like particles and bacteria from entering the lungs.

The researchers wrote that their results “suggest humans are routinely exposed” to carbon nanotubes. They also suggested previous studies that link the carbon content of airway macrophages and the decline of lung function should be reconsidered in light of the new findings. Moussa confirmed his lab will continue to study the impact of man-made nanotubes on health.

The cells were taken from 69 randomly selected asthma patients aged 2 to 17 who underwent routine fiber-optic bronchoscopies as part of their treatment. For ethical reasons, no cells from healthy patients were analyzed, but because nanotubes were found in all of the samples, the study led the researchers to conclude that carbon nanotubes are likely to be found in everybody.

The study notes but does not make definitive conclusions about the controversial proposition that carbon nanotube fibers may act like asbestos, a proven carcinogen. But the authors reminded that “long carbon nanotubes and large aggregates of short ones can induce a granulomatous (inflammation) reaction.”

The study partially answers the question of what makes up the black material inside alveolar macrophages, the original focus of the study. The researchers found single-walled and multiwalled carbon nanotubes and amorphous carbon among the cells, as well as in samples swabbed from the tailpipes of cars in Paris and dust from various buildings in and around the city.

The news release goes on to detail how the research was conducted,

“The concentrations of nanotubes are so low in these samples that it’s hard to believe they would cause asthma, but you never know,” Wilson said. “What surprised me the most was that carbon nanotubes were the major component of the carbonaceous pollution we found in the samples.”

The nanotube aggregates in the cells ranged in size from 10 to 60 nanometers in diameter and up to several hundred nanometers in length, small enough that optical microscopes would not have been able to identify them in samples from former patients. The new study used more sophisticated tools, including high-resolution transmission electron microscopy, X-ray spectroscopy, Raman spectroscopy and near-infrared fluorescence microscopy to definitively identify them in the cells and in the environmental samples.

“We collected samples from the exhaust pipes of cars in Paris as well as from busy and non-busy intersections there and found the same type of structures as in the human samples,” Wilson said.

“It’s kind of ironic. In our laboratory, working with carbon nanotubes, we wear facemasks to prevent exactly what we’re seeing in these samples, yet everyone walking around out there in the world probably has at least a small concentration of carbon nanotubes in their lungs,” he said.

The researchers also suggested that the large surface areas of nanotubes and their ability to adhere to substances may make them effective carriers for other pollutants.

The study followed one released by Rice and Baylor College of Medicine earlier this month with the similar goal of analyzing the black substance found in the lungs of smokers who died of emphysema. That study found carbon black nanoparticles that were the product of the incomplete combustion of such organic material as tobacco.

Here’s an image of a sample,

Caption: Carbon nanotubes (the long rods) and nanoparticles (the black clumps) appear in vehicle exhaust taken from the tailpipes of cars in Paris. The image is part of a study by scientists in Paris and at Rice University to analyze carbonaceous material in the lungs of asthma patients. They found that cars are a likely source of nanotubes found in the patients.
Credit: Courtesy of Fathi Moussa/Paris-Saclay University

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

Anthropogenic Carbon Nanotubes Found in the Airways of Parisian Children by Jelena Kolosnjaj-Tabi, Jocelyne Just, Keith B. Hartman, Yacine Laoudi, Sabah Boudjemaa, Damien Alloyeau, Henri Szwarc, Lon J. Wilson, & Fathi Moussa. EBioMedicine doi:10.1016/j.ebiom.2015.10.012 Available online 9 October 2015

This paper is open access.

ETA Oct. 26, 2015: Dexter Johnson, along with Dr. Andrew Maynard, provides an object lesson on how to read science research in an Oct. 23, 2015 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers]),

“From past studies, the conditions in combustion engines seem to favor the production of at least some CNTs (especially where there are trace metals in lubricants that can act as catalysts for CNT growth),” explained Andrew Maynard Director, Risk Innovation Lab and Professor, School for the Future of Innovation in Society at Arizona State University, in an e-mail interview. Says Maynard:

What, to my knowledge, is still not known, is the relative concentrations of CNT in ambient air that may be inhaled, the precise nature of these CNT in terms of physical and chemical structure, and the range of sources that may lead to ambient CNT. This is important, as the potential for fibrous particles to cause lung damage depends on characteristics such as their length—and many of the fibers shown in the paper appear too short to raise substantial concerns.”

…

Nonetheless, Maynard praises the research for establishing that these carbon nanotube-like fibers are part of the urban aerosol and therefore end up in the lungs of anyone who breathes it in. However, he cautions that the findings don’t provide information on the potential health risks associated with these exposures.

It’s a good read not only for the information but the mild snarkiness (assuming you find that kind of thing amusing) that spices up the piece.

Dunkin’ Donuts and nano titanium dioxide

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It’s been a busy few days for titanium dioxide, nano and otherwise, as the news about its removal from powdered sugar in Dunkin’ Donuts products ripples through the nano blogosphere. A March 6, 2015 news item on Azonano kicks off the discussion with an announcement,

Dunkin’ Brands, the parent company of the Dunkin’ Donuts chain, has agreed to remove titanium dioxide, a whitening agent that is commonly a source of nanomaterials, from all powdered sugar used to make the company’s donuts. As a result of this progress, the advocacy group As You Sow has withdrawn a shareholder proposal asking Dunkin’ to assess and reduce the risks of using nanomaterials in its food products.

Here’s a brief recent history of Dunkin’ Donuts and nano titanium dioxide from my Aug. 21, 2014 posting titled, FOE, nano, and food: part two of three (the problem with research),

Returning to the ‘debate’, a July 11, 2014 article by Sarah Shemkus for a sponsored section in the UK’s Guardian newspaper highlights an initiative taken by an environmental organization, As You Sow, concerning titanium dioxide in Dunkin’ Donuts’ products (Note: A link has been removed),

The activists at environmental nonprofit As You Sow want you to take another look at your breakfast doughnut. The organization recently filed a shareholder resolution asking Dunkin’ Brands, the parent company of Dunkin’ Donuts, to identify products that may contain nanomaterials and to prepare a report assessing the risks of using these substances in foods.

Their resolution received a fair amount of support: at the company’s annual general meeting in May, 18.7% of shareholders, representing $547m in investment, voted for it. Danielle Fugere, As You Sow’s president, claims that it was the first such resolution to ever receive a vote. Though it did not pass, she says that she is encouraged by the support it received.

“That’s a substantial number of votes in favor, especially for a first-time resolution,” she says.

The measure was driven by recent testing sponsored by As You Sow, which found nanoparticles of titanium dioxide in the powdered sugar that coats some of the donut chain’s products. [emphasis mine] An additive widely used to boost whiteness in products from toothpaste to plastic, microscopic titanium dioxide has not been conclusively proven unsafe for human consumption. Then again, As You Sow contends, there also isn’t proof that it is harmless.

“Until a company can demonstrate the use of nanomaterials is safe, we’re asking companies either to not use them or to provide labels,” says Fugere. “It would make more sense to understand these materials before putting them in our food.”

As I understand it, Dunkin’ Donuts will be removing all titanium dioxide, nano-sized or other, from powdered sugar used in its products. It seems As You Sow’s promise to withdraw its July 2104 shareholder resolution is the main reason for Dunkin’ Donuts’ decision. While I was and am critical of Dunkin’ Donuts’ handling of the situation with As You Sow, I am somewhat distressed that the company seems to have acquiesced on the basis of research which is, at best, inconclusive.

Dr. Andrew Maynard, director of the University of Michigan Risk Science Centre, has written a substantive analysis of the current situation regarding nano titanium dioxide in a March 12, 2015 post on his 2020 Science blog (Note: Links have been removed),

Titanium dioxide (which isn’t the same thing as the metal titanium) is an inert, insoluble material that’s used as a whitener in everything from paper and paint to plastics. It’s the active ingredient in many mineral-based sunscreens. And as a pigment, is also used to make food products look more appealing.

Part of the appeal to food producers is that titanium dioxide is a pretty dull chemical. It doesn’t dissolve in water. It isn’t particularly reactive. It isn’t easily absorbed into the body from food. And it doesn’t seem to cause adverse health problems. It just seems to do what manufacturers want it to do – make food look better. It’s what makes the powdered sugar coating on donuts appear so dense and snow white. Titanium dioxide gives it a boost.

And you’ve probably been consuming it for years without knowing. In the US, the Food and Drug Administration allows food products to contain up to 1% food-grade titanium dioxide without the need to include it on the ingredient label. Help yourself to a slice of bread, a bar of chocolate, a spoonful of mayonnaise or a donut, and chances are you’ll be eating a small amount of the substance.

…

Andrew goes on to describe the concerns that groups such as You As Sow have (Note: Links have been removed),

For some years now, researchers have recognized that some powders become more toxic the smaller the individual particles are, and titanium dioxide is no exception. Pigment grade titanium dioxide – the stuff typically used in consumer products and food – contains particles around 200 nanometers in diameter, or around one five hundredth the width of a human hair. Inhale large quantities of these titanium dioxide particles (I’m thinking “can’t see your hand in front of your face” quantities), and your lungs would begin to feel it.

If the particles are smaller though, it takes much less material to cause the same effect.

But you’d still need to inhale very large quantities of the material for it to be harmful. And while eating a powdered donut can certainly be messy, it’s highly unlikely that you’re going to end up stuck in a cloud of titanium dioxide-tinted powdered sugar coating!

… Depending on what they are made of and what shape they are, research has shown that some nanoparticles are capable of getting to parts of the body that are inaccessible to larger particles. And some particles are more chemically reactive because of their small size. Some may cause unexpected harm simply because they are small enough to throw a nano-wrench into the nano-workings of your cells.

This body of research is why organizations like As You Sow have been advocating caution in using nanoparticles in products without appropriate testing – especially in food. But the science about nanoparticles isn’t as straightforward as it seems.

As Andrew notes,

First of all, particles of the same size but made of different materials can behave in radically different ways. Assuming one type of nanoparticle is potentially harmful because of what another type does is the equivalent of avoiding apples because you’re allergic to oysters.

He describes some of the research on nano titanium dioxide (Note: Links have been removed),

… In 2004 the European Food Safety Agency carried out a comprehensive safety review of the material. After considering the available evidence on the same materials that are currently being used in products like Dunkin’ Donuts, the review panel concluded that there no evidence for safety concerns.

Most research on titanium dioxide nanoparticles has been carried out on ones that are inhaled, not ones we eat. Yet nanoparticles in the gut are a very different proposition to those that are breathed in.

Studies into the impacts of ingested nanoparticles are still in their infancy, and more research is definitely needed. Early indications are that the gastrointestinal tract is pretty good at handling small quantities of these fine particles. This stands to reason given the naturally occurring nanoparticles we inadvertently eat every day, from charred foods and soil residue on veggies and salad, to more esoteric products such as clay-baked potatoes. There’s even evidence that nanoparticles occur naturally inside the gastrointestinal tract.

He also probes the issue’s, nanoparticles, be they titanium dioxide or otherwise, and toxicity, complexity (Note: Links have been removed),

There’s a small possibility that we haven’t been looking in the right places when it comes to possible health issues. Maybe – just maybe – there could be long term health problems from this seemingly ubiquitous diet of small, insoluble particles that we just haven’t spotted yet. It’s the sort of question that scientists love to ask, because it opens up new avenues of research. It doesn’t mean that there is an issue, just that there is sufficient wiggle room in what we don’t know to ask interesting questions.

… While there is no evidence of a causal association between titanium dioxide in food and ill health, some studies – but not all by any means – suggest that large quantities of titanium dioxide nanoparticles can cause harm if they get to specific parts of the body.

For instance, there are a growing number of published studies that indicate nanometer sized titanium dioxide particles may cause DNA damage at high concentrations if it can get into cells. But while these studies demonstrate the potential for harm to occur, they lack information on how much material is needed, and under what conditions, for significant harm. And they tend to be associated with much larger quantities of material than anyone is likely to be ingesting on a regular basis.

They are also counterbalanced by studies that show no effects, indicating that there is still considerable uncertainty over the toxicity or otherwise of the material. It’s as if we’ve just discovered that paper can cause cuts, but we’re not sure yet whether this is a minor inconvenience or potentially life threatening. In the case of nanoscale titanium dioxide, it’s the classic case of “more research is needed.”

I strongly suggest reading Andrew’s post in its entirety either here on the University of Michigan website or here on The Conversation website.

Dexter Johnson in a March 11, 2015 post on his Nanoclast blog also weighs in on the discussion. He provides a very neat summary of the issues along with these observations (Note Links have been removed),

With decades of TiO2 being in our food supply and no reports of toxic reactions, it would seem that the threshold for proof is extremely high, especially when you combine the term “nano” with “asbestos”.

As You Sow makes sure to point out that asbestos is a nanoparticle. While the average diameter of an asbestos fiber is around 20 to 90 nm, their lengths varied between 200 nm and 200 micrometers.

The toxic aspect of asbestos was not its diameter, but its length. …

In addition to his summary Dexter highlights As You Sows attempt to link titanium dioxide nanoparticles to asbestos. I suggest reading his post for an informed description of what made asbestos so toxic (here) and why the linkage seems specious at this time.

For anyone interested in how As You Sow managed to introduce asbestos toxicity issues into a discussion about nano titanium dioxide and food products, there’s this from As You Sow’s FAQs (frequently asked questions) about nanomaterials in food page,

Why are nanomaterials in food important to investors?

…

When technology is used before ensuring that it is safe for humans and the environment, and before regulatory standards exist, companies can be exposed to significant financial, legal, and reputational risk. The limited studies that exist on nanomaterials, including nanoscale titanium dioxide*, have indicated that ingestion of these particles may pose health hazards.

The inaction of regulators does not protect companies, especially when the regulators themselves warn of the dangers of nanoparticles’ largely unknown risks. Draft guidance issued by the U.S. Food and Drug Administration raises questions about the safety of nanoparticles and demonstrates the general lack of knowledge about the technology and its effects. (1)

Asbestos litigation is a good example of the risks that can arise from using an emerging technology before it is proven safe. Use of asbestos (a nanomaterial) has created the longest, most expensive mass tort in national history with total U.S. costs now standing at over $250 billion. (2) If companies been asked to investigate and minimize or avoid risks prior to adopting asbestos technology, a sad and expensive chapter in worker harm could have been avoided.

* Titanium dioxide is a common pigment and FDA-approved food additive. It is used as a whitener, a dispersant, and a thickener.

While I don’t particularly appreciate fear-mongering as a tactic, the strategy of targeting investors and their concerns, seems to have helped As You Sow win its way.

Nanozen: protecting us from nanoparticles (maybe)

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Friday, Oct. 24, 2014 the Vancouver Sun (Canada) featured a local nanotechnology company, Nanozen in an article by ‘digital life’ writer, Gillian Shaw. Unfortunately, the article is misleading. Before noting the issues, it should be said that most reporters don’t have much time to prepare stories and are often asked to write on topics that are new or relatively unknown to them. It is a stressful position to be in especially when one is reliant on the interviewee’s expertise and agenda. As for the interviewee, sometimes scientists get excited and enthused and don’t speak with their usual caution.

The article starts off in an unexceptionable manner,

Vancouver startup Nanozen is a creating real-time, wearable particle sensor for use in mines, mills and other industrial locations where dust and other particles can lead to dangerous explosions and debilitating respiratory diseases.

The company founder and, presumably, lead researcher Winnie Chu is described as a former professor of environmental health at the University of British Columbia who has devoted herself to developing a new means of monitoring particles, in particular nanoparticles. Chu is quoted as saying this,

“The current technology is not sufficient to protect workers or the community when concentrations exceed the acceptable level,” she said.

It seems ominous and is made more so with this,

Chu said more than 90 per cent of the firefighters who responded to the 9/11 disaster developed lung disease, having walked into a site full of small and very damaging particles in the air.

“Those nanoparticles go deep into your lungs and cause inflammation and other problems,” Chu said.

It seems odd to mention this particular disaster. The lung issues for the firefighters, first responders and people living close to the site of World Trade Centers collapse are due to a complex mix of materials in the air. Most of the research I can find focuses on micrsoscale particles such as the work from the University of California at Davis’s Delta Group (Detection and Evaluation of the Long-Range Transport of Aerosols). From the Group’s World Trade Center webpage,

The fuming World Trade Center debris pile was a chemical factory that exhaled pollutants in particularly dangerous forms that could penetrate deep into the lungs of workers at Ground Zero, says a new study by UC Davis air-quality experts.

You can find the group’s presentation (-Presentation download (WTC aersols ACS 2003.ppt; 7,500kb)) to an American Chemical Society meeting in 2003 along more details such as this on their webpage,

The conditions would have been “brutal” for people working at Ground Zero without respirators and slightly less so for those working or living in immediately adjacent buildings, said the study’s lead author, Thomas Cahill, a UC Davis professor emeritus of physics and atmospheric science and research professor in engineering.

“Now that we have a model of how the debris pile worked, it gives us a much better idea of what the people working on and near the pile were actually breathing,” Cahill said. “Our first report was based on particles that we collected one mile away. This report gives a reasonable estimate of what type of pollutants were actually present at Ground Zero.

“The debris pile acted like a chemical factory. It cooked together the components of the buildings and their contents, including enormous numbers of computers, and gave off gases of toxic metals, acids and organics for at least six weeks.”

The materials found by this group were not at the nanoscale. In fact, the focus was then and subsequently on materials such as glass shards, asbestos, and metallic aerosols at the microscale, all of which can cause well documented health problems. No doubt effective monitoring would have been helpful It seems the critical issue in the early stages of the disaster was access to a respirator. Also, effective monitoring at later stages which did not seem to have happened would have been a good idea.

A 2004 (?) New York Magazine article by Jennifer Senior titled ‘Fallout‘ had this to say about the air content,

Here, today, is what we know about the dust and air at ground zero: It contained glass shards, pulverized concrete, and many carcinogens, including hundreds of thousands of pounds of asbestos, tens of thousands of pounds of lead, mercury, cadmium, dioxins, PCBs, and polycyclic aromatic hydrocarbons, or PAHs. It also contained benzene. According to a study done by the U.S. Geological Survey, the dust was so caustic in places that its pH exceeded that of ammonia. Thomas Cahill, a scientist who analyzed the plumes from a rooftop one mile away, says that the levels of acids, insoluble particles, high-temperature organic materials, and metals were in most cases higher in very fine particles (which can slip deep into the lungs) than anyplace ever recorded on earth, including the oil fires of Kuwait.

The article describes at some length the problems for first responders and for those who later moved back into their homes nearby the disaster site under the impression the air was clean.

Getting back to the nanoscale, there were carbon nanotubes (CNTs) present as this 2009 research paper, Case Report: Lung Disease in World Trade Center Responders Exposed to Dust and Smoke: Carbon Nanotubes Found in the Lungs of World Trade Center Patients and Dust Samples, noted in relation to a sample of seven patients,

It may well be the most frequent injury pattern in exposed patients with severe respiratory impairment. b) Interstitial disease was present in four cases (Patients A, B, C, and E), characterized by a generally bronchiolocentric pattern of interstitial inflammation and fibrosis of variable severity. The lungs of these patients contained large amounts of silicates, and three of them showed nanotubes.

…

CNT of commercial origin, common now, would not have been present in substantial numbers in the WTC complex before the disaster in 2001. However, the high temperatures generated during the WTC disaster as a result of the combustion of fuel in the presence of carbon and metals would have been sufficient to locally generate large numbers of CNT. This scenario could have caused the generation of CNT that we have noted in the dust samples and in the lung biopsy specimens.

Given that CNTs are more common now, it would suggest that a monitor for nanoscale materials such as Chu’s proposed equipment could be an excellent idea. Unfortunately, it’s not clear what Chu is trying to achieve as she appears to make a blunder in the article,

Chu said environmental agencies require testing to distinguish between particles equal to or less than 10 microns and smaller particles 2.5 microns or less.

“When we inhale we inhale both size particles but they go into different parts of the lung,” said Chu, who said research shows the smaller the particle the higher the toxicity. [emphasis mine] The monitor she has developed can detect particles as small as one micron and even less.

The word ‘nanoparticle’ is often used generically to include, CNTs, quantum dots, silver nanoparticles, etc. as Chu seems to be doing throughout the article. The only nanomaterial/nanoparticle that researchers agree unequivocally cause lung problems are long carbon nanotubes which resemble asbestos fibres. This is precisely the opposite of Chu’s statement.

For validation, you can conduct your own search or you can check Swiss toxicologist Harald Krug’s (mentioned in my Nanosafety research: a quality control issue posting of Oct. 30, 2014) statement that most health and safety research of nanomaterials and the resultant conclusions are problematic. But he too is unequivocal with regard long carbon nanotubes (from Krug’s study, Nanosafety Research—Are We on the Right Track?).

Comparison of instillation and inhalation experiments: instillation studies have to be carried out with relatively high local doses and, thus, more often meet overload conditions than inhalation studies. Transient inflammatory effects have been observed frequently in both types of lung exposure, irrespective of the type of ENMs used for the experiment. This finding suggests an unspecific particle effect; moreover, the biological response seems to be comparable to a scenario involving exposure to fine dust. Prominent exceptions are long and rigid carbon nanotube (CNT) bundles, which induce a severe tissue reaction (chronic inflammation) that may ultimately result in tumor formation. Overall, the evaluated studies showed no indication of a “nanospecific” effect in the lung. [from the Summary section; 2nd bulleted point]

You can find the Nanozen website here but there doesn’t appear to be any information on the site yet. These search terms ‘about’, ‘team’, ‘technology’, and ‘product’ yielded no results on website as of Oct. 30, 2014 at 1000 hours PDT.

Nanotechnology analogies and policy

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There’s a two part essay titled, Regulating Nanotechnology Via Analogy (part 1, Feb. 12, 2013 and part 2, Feb. 18, 2013), by Patrick McCray on his Leaping Robot blog that is well worth reading if you are interested in the impact analogies can have on policymaking.

Before launching into the analogies, here’s a bit about Patrick McCray from the Welcome page to his website, (Note: A link has been removed),

As a professor in the History Department of the University of California, Santa Barbara and a co-founder of the Center for Nanotechnology in Society, my work focuses on different technological and scientific communities and their interactions with the public and policy makers. For the past ten years or so, I’ve been especially interested in the historical development of so-called “emerging technologies,” whenever they emerged.

I hope you enjoy wandering around my web site. The section of it that changes most often is my Leaping Robot blog. I update this every few weeks or so with an extended reflection or essay about science and technology, past and future.

In part 1 (Feb. 12, 2013) of the essay, McCray states (Note: Links and footnotes have been removed),

[Blogger’s note: This post is adapted from a talk I gave in March 2012 at the annual Business History Conference; it draws on research done by Roger Eardley-Pryor, an almost-finished graduate student I’m advising at UCSB [University of California at Santa Barbara], and me. I’m posting it here with his permission. This is the first of a two-part essay…some of the images come from slides we put together for the talk.]

…

Over the last decade, a range of actors – scientists, policy makers, and activists – have used historical analogies to suggest different ways that risks associated with nanotechnology – especially those concerned with potential environmental implications – might be minimized. Some of these analogies make sense…others, while perhaps effective, are based on a less than ideal reading of history.

Analogies have been used before as tools to evaluate new technologies. In 1965, NASA requested comparisons between the American railroad of the 19^th century and the space program. In response, MIT historian Bruce Mazlish wrote a classic article that analyzed the utility and limitations of historical analogies. Analogies, he explained, function as both model and myth. Mythically, they offer meaning and emotional security through an original archetype of familiar knowledge. Analogies also furnish models for understanding by construing either a structural or a functional relationship. As such, analogies function as devices of anticipation which what today is fashionably called “anticipatory governance.”They also can serve as a useful tool for risk experts.

McCray goes on to cover some of the early discourse on nanotechnology, the players, and early analogies. While the focus is on the US, the discourse reflects many if not all of the concerns being expressed internationally.

In part 2 posted on Feb. 18, 2013 McCray mentions four of the main analogies used with regard to nanotechnology and risk (Note: Footnotes have been removed),

Example #1 – Genetically Modified Organisms

In April 2003, Prof. Vicki Colvin testified before Congress. A chemist at Rice University, Colvin also directed that school’s Center for Biological and Environmental Nanotechnology. This “emerging technology,” Colvin said, had a considerable “wow index.” However, Colvin warned, every promising new technology came with concerns that could drive it from “wow into yuck and ultimately into bankrupt.” To make her point, Colvin compared nanotech to recent experiences researchers and industry had experienced with genetically modified organisms. Colvin’s analogy – “wow to yuck” – made an effective sound bite. But it also conflated two very different histories of two specific emerging technologies.

While some lessons from GMOs are appropriate for controlling the development of nanotechnology, the analogy doesn’t prove watertight. Unlike GMOs, nanotechnology does not always involve biological materials. And genetic engineering in general, never enjoyed any sort of unalloyed “wow” period. There was “yuck” from the outset. Criticism accompanied GMOs from the very start. Furthermore, giant agribusiness firms prospered handsomely even after the public’s widespread negative reactions to their products. Lastly, living organisms – especially those associated with food – designed for broad release into the environment were almost guaranteed to generate concerns and protests. Rhetorically, the GMO analogy was powerful…but a deeper analysis clearly suggests there were more differences than similarities.

McCray offers three more examples of analogies used to describe nanotechnology: asbestos, (radioactive) fallout, and Recombinant DNA which he dissects and concludes are not the best analogies to be using before offering this thought,

So — If historical analogies teach can teach us anything about the potential regulation of nano and other emerging technologies, they indicate the need to take a little risk in forming socially and politically constructed definitions of nano. These definitions should be based not just on science but rather mirror the complex and messy realm of research, policy, and application. No single analogy fits all cases but an ensemble of several (properly chosen, of course) can suggest possible regulatory options.

I recommend reading both parts of McCray’s essay in full. It’s a timely piece especially in light of a Feb. 28, 2013 article by Daniel Hurst for Australian website, theage.com.au, where a union leader raises health fears about nanotechnology by using the response to asbestos health concerns as the analogy,

Union leader Paul Howes has likened nanotechnology to asbestos, calling for more research to ease fears that the growing use of fine particles could endanger manufacturing workers.

”I don’t want to make the mistake that my predecessors made by not worrying about asbestos,” the Australian Workers Union secretary said.

I have covered the topic of carbon nanotubes and asbestos many times, one of the latest being this Jan. 16, 2013 posting. Not all carbon nanotubes act like asbestos; the long carbon nanotubes present the problems.

The yin and the yang of carbon nanotubes and toxicity

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Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Researchers at the University College of London (UCL), France’s Centre national de la recherche scientifique (CNRS), and Italy’s University of Trieste have determined that carbon nanotube toxicity issues can be addressed be reducing their length and treating them chemically. From the Jan. 15,2013 news item on ScienceDaily,

In a new study, published January 15 [2013] in the journal Angewandte Chemie, evidence is provided that the asbestos-like reactivity and pathogenicity reported for long, pristine nanotubes can be completely alleviated if their surface is modified and their effective length is reduced as a result of chemical treatment.

First atomically described in the 1990s, carbon nanotubes are sheets of carbon atoms rolled up into hollow tubes just a few nanometres in diameter. Engineered carbon nanotubes can be chemically modified, with the addition of chemotherapeutic drugs, fluorescent tags or nucleic acids — opening up applications in cancer and gene therapy.

Furthermore, these chemically modified carbon nanotubes can pierce the cell membrane, acting as a kind of ‘nano-needle’, allowing the possibility of efficient transport of therapeutic and diagnostic agents directly into the cytoplasm of cells.

Among their downsides however, have been concerns about their safety profile. One of the most serious concerns, highlighted in 2008, involves the carcinogenic risk from the exposure and persistence of such fibres in the body. Some studies indicate that when long untreated carbon nanotubes are injected to the abdominal cavity of mice they can induce unwanted responses resembling those associated with exposure to certain asbestos fibres.

In this paper, the authors describe two different reactions which ask if any chemical modification can render the nanotubes non-toxic. They conclude that not all chemical treatments alleviate the toxicity risks associated with the material. Only those reactions that are able to render carbon nanotubes short and stably suspended in biological fluids without aggregation are able to result in safe, risk-free material.

Here’s a citation and link for this latest research, from the ScienceDaily news item where you can also read the lead researcher’s comments about carbon nanotubes, safety, and unreasonable proposals to halt production,

Hanene Ali-Boucetta, Antonio Nunes, Raquel Sainz, M. Antonia Herrero, Bowen Tian, Maurizio Prato, Alberto Bianco, Kostas Kostarelos. Asbestos-like Pathogenicity of Long Carbon Nanotubes Alleviated by Chemical Functionalization. Angewandte Chemie International Edition, 2013; DOI: 10.1002/anie.201207664

The article is behind a paywall. I have mentioned long carbon nanotubes and their resemblance to asbestos fibres in several posts. The Oct. 26, 2009 posting [scroll down about 1/3 of the way] highlights research which took place after the study where mice had carbon nanotubes injected into their bellies; in this second piece of research they inhaled the nanotubes.

ETA Jan. 21, 2013: Dexter Johnson gives context and commentary about this latest research into long multiwalled nanotubes (MWNTs) which he sums up as the answer to this question “What if you kept the MWNTs short?” in a Jan. 18, 2013 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website)

Health science writing? Australian writer accuses gym equipment of killing you through nanotechnology

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Toby McCasker’s Sept. 30, 2012 article for news.com.au is one of the more peculiar pieces I’ve seen about nanotechnology and its dangers. From the article,

Is gym equipment killing you?

THE nanofibres that make up sports and gym equipment just might be doing you more harm than good.

McCasker then blesses us with this wonderful, wonderful passage where he explains his concern,

Why is this (maybe) bad? Nanotechnology sounds awesome, after all. Very cyberpunk. Inject them into your dude piston and become a thrumming love-machine, all that. [emphases mine] They’re maybe bad because researchers from the University of Edinburgh in the UK have just discovered that some nanofibres bear a resemblance to asbestos fibres, which can cause lung cancer.

You can’t inject nanotechnology. Since it’s a field of study, it would be the equivalent of injecting biology or quantum mechanics.

As for nanotechnology being cyberpunk, here’s how Cyberpunk is defined in The Free Dictionary,

Noun   1.         cyberpunk – a programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism

cyber-terrorist, hacker

act of terrorism, terrorism, terrorist act – the calculated use of violence (or the threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimidation or coercion or instilling fear

coder, computer programmer, programmer, software engineer – a person who designs and writes and tests computer programs

terrorist – a radical who employs terror as a political weapon; usually organizes with other terrorists in small cells; often uses religion as a cover for terrorist activities

2.         cyberpunk – a writer of science fiction set in a lawless subculture of an oppressive society dominated by computer technology

author, writer – writes (books or stories or articles or the like) professionally (for pay)

3.         cyberpunk – a genre of fast-paced science fiction involving oppressive futuristic computerized societies

science fiction – literary fantasy involving the imagined impact of science on society

The closest definition that fits McCasker’s usage is this description (the passage by Lawrence Person) of cyberpunk, a post-modern science fiction genre, in Wikipedia,

Cyberpunk plots often center on a conflict among hackers, artificial intelligences, and megacorporations, and tend to be set in a near-future Earth, rather than the far-future settings or galactic vistas found in novels such as Isaac Asimov’s Foundation or Frank Herbert’s Dune. The settings are usually post-industrial dystopias but tend to be marked by extraordinary cultural ferment and the use of technology in ways never anticipated by its creators (“the street finds its own uses for things”). Much of the genre’s atmosphere echoes film noir, and written works in the genre often use techniques from detective fiction.

“Classic cyberpunk characters were marginalized, alienated loners who lived on the edge of society in generally dystopic futures where daily life was impacted by rapid technological change, an ubiquitous datasphere of computerized information, and invasive modification of the human body.” – Lawrence Person

It’s the part about “invasive modification of the human body” which seems closest to McCasker’s ” inject them into your dude piston” (dude piston is my new favourite phrase).

As for the reference to nanofibres, McCasker is correct. There are carbon nanotubes that resemble asbestos fibres and there is concern for anyone who may ingest them. As far as I know, the people at greatest risk would be workers who are exposed to the carbon nanotubes directly. I have not heard of anyone getting sick because of their golf clubs where carbon nanotubes are often used to make them lighter and stronger.

The research (mentioned in my Aug. 22, 2012 posting) at the University of Edinburgh that McCasker cites is important because it adds to a body of substantive research work on this issue regarding carbon nanotubes, asbestos, and the possibility of mesothelioma and bears no mention of gym equipment.

It’s the length, not the size that matters with nanofibres such as carbon nanotubes

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The Aug. 22, 2012 news item on Nanowerk by way of Feedzilla features some research at the University of Edinburgh which determined that short nanofibres do not have the same effect on lung cells as longer fibres do. From the news item, here’s a description of why this research was undertaken

Nanofibres, which can be made from a range of materials including carbon, are about 1,000 times smaller than the width of a human hair and can reach the lung cavity when inhaled.

This may lead to a cancer known as mesothelioma, which is known to be caused by breathing in asbestos fibres, which are similar to nanofibres.

I wrote about research at Brown University which explained why some fibres get stuck in lung cells in a Sept. 22, 2011 posting titled, Why asbestos and carbon nanotubes are so dangerous to cells. The short answer is: if the tip is rounded, the cell mistakes the fibre for a sphere and, in error, it attempts to absorb it. Here’s some speculation on my part about what the results might mean (from my Sept. 22, 2011 posting),

The whole thing has me wondering about long vs. short carbon nanotubes. Does this mean that short carbon nanotubes can be ingested successfully? If so, at what point does short become too long to ingest?

The University of Edinburgh Aug. 22, 2012 news release provides answer to last year’s speculation about length,

The University study found that lung cells were not affected by short fibres that were less than five-thousandths of a millimetre long.

However, longer fibres can reach the lung cavity, where they become stuck and cause disease.

We knew that long fibres, compared with shorter fibres, could cause tumours but until now we did not know the cut-off length at which this happened. Knowing the length beyond which the tiny fibres can cause disease is important in ensuring that safe fibres are made in the future as well as helping to understand the current risk from asbestos and other fibres, [said] Ken Donaldson, Professor of Respiratory Toxicology.

Sometimes, I surprise myself. I think I’ll take a moment to bask. … Done now!

Here’s my final thought, while this research suggests short length nanofibres won’t cause mesothelioma, this doesn’t rule out other potential problems. So, let’s celebrate this new finding and then get back to investigating nanofibres and their impact on health.

FrogHeart

Commentary about nanotech, science policy and communication, society, and the arts

Tag Archives: asbestos

Gold nanotubes for treating mesothelioma?

Futurography’s nanotechnology series: a digest

Not enough talk about nano risks?

Inadvertent carbon nanotube production from your car

Dunkin’ Donuts and nano titanium dioxide

Nanozen: protecting us from nanoparticles (maybe)

Nanotechnology analogies and policy

The yin and the yang of carbon nanotubes and toxicity

Health science writing? Australian writer accuses gym equipment of killing you through nanotechnology

It’s the length, not the size that matters with nanofibres such as carbon nanotubes