Tag Archives: titanium dioxide

Sunscreen and nano time, again (part 1)

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Before launching into another discussion about the safety of sunscreens with titanium dioxide and/or zinc oxide nanoparticles, I’m going to mention uncertainty and risk. First, the notion of uncertainty that I”m using is proposed in a theory coined Knightian Uncertainty and comes from the field of economics. Here’s a definition from an article by Peter Dizikes at the Massachusetts Institute of Technology News Office,

Frank Knight was an idiosyncratic economist who formalized a distinction between risk and uncertainty in his 1921 book, Risk, Uncertainty, and Profit. As Knight saw it, an ever-changing world brings new opportunities for businesses to make profits, but also means we have imperfect knowledge of future events. Therefore, according to Knight, risk applies to situations where we do not know the outcome of a given situation, but can accurately measure the odds. Uncertainty, on the other hand, applies to situations where we cannot know all the information we need in order to set accurate odds in the first place.

Making a distinction between uncertainty and risk is very helpful in trying to understand some of the less pleasant possibilities of nanotechnology-enabled products. As more research about titanium dioxide and zinc oxide nanoparticles in sunscreens is published, there’s more information that can be used to assess risk.

With regard to health, two categories of risk are commonly discussed, absolute risk and relative risk. Here is a definition excerpted  from the Patient UK website,

Absolute risk of a disease is your risk of developing the disease over a time-period. We all have absolute risks of developing various diseases such as heart disease, cancer, stroke, etc. The same absolute risk can be expressed in different ways. For example, say you have a 1 in 10 risk of developing a certain disease in your life. This can also be said a 10% risk, or a 0.1 risk – depending if you use percentages or decimals.

Relative risk is used to compare the risk in two different groups of people. For example, the groups could be ‘smokers’ and ‘non-smokers’. All sorts of groups are compared to others in medical research to see if belonging to a group increases or decreases your risk of developing certain diseases. For example, research has shown that smokers have a higher risk of developing heart disease compared to (relative to) non-smokers.

In these scenarios (heart diseases and smoking vs. non-smoking) there’s enough information to make an informed guess even though a degree of uncertainty still exists. By contrast, the situation with nanosunscreens doesn’t lend itself to an analysis of absolute or relative risk as basic information is still being gathered.

Meanwhile the civil society/activist group, Friends of the Earth (FOE) has renewed their call to remove sunscreens with titanium dioxide and/or zinc oxide nanoparticles from the market. Andrew Maynard at 2020 Science has very carefully analysed the six studies that FOE has published on their nanosunscreen page. From Andrew’s posting,

As these are evidence-based statements, I thought it would be worth while going through them, and taking a look at the evidence they are based on:

FoE: “Manufactured nanomaterials used in sunscreens (such as zinc oxide and titanium oxide) can Damage human colon cells: A study from the University of Utah showed that nano zinc oxide is toxic to colon cells even in small amounts. The scientists called for more research and warned that the evidence is especially concerning for children who are more likely to accidently ingest sunscreen. The colon is vital because it eliminates food waste and absorbs important nutrients.”

This was a study that looked at interactions between zinc oxide (ZnO) particles and cells derived from the human colon, and was carried out in vitro (i.e. in a cell culture rather than in animals or people). It did indeed indicate that nanometer scale ZnO particles were around twice as potent as larger ZnO particles in their ability to kill these cells under idealized conditions. But the research also emphasized that direct contact with the cells was needed for a nanoscale particle-related effect. In fact, the title of the paper was “ZnO Particulate Matter Requires Cell Contact for Toxicity in Human Colon Cancer Cells,” emphasizing this point above the higher potency of the more finely structured particles.

The research was interesting, but did not resolve whether zinc oxide particles could survive long enough in the gut to come into contact with cells lining the colon, whether interactions like those observed in the laboratory are plausible under real-world conditions, and what levels of exposure would be needed to cause significant harm. The research also indicated that larger particles of zinc oxide – similar to particles that have been used in sunscreens and other topical creams for decades – were toxic to cells under the conditions of the study.

So regular and nanosized particles of zinc oxide are both toxic to colon cells with the nanosized particles being 2 x more toxic. That’s not great but we’ve been using regular sized zinc oxide particles  for quite some time and, as far as I know, no one claims that it causes colon cancer.  Also, these tests were conducted with cultures (i. e. not inside the human or any other type of body) so there’s no proof that zinc oxide of any size survives long enough to enter the colon. If there were an absolute risk associated with using regular sized zinc oxide particles, theoretically we could infer an absolute risk for nanosized zinc oxide particles.

More later today.

Sunscreen season and the latest from the Environmental Working Group

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Last year (July 9, 2009), I wrote about the Environmental Working Group (EWG) and their meta-analysis of the studies conducted on the use of titanium dioxide and zinc oxide nanoparticles in sunscreens. Much to the EWG’s surprise, they gave the sunscreens with nanoparticles a passing grade. The EWG still examines sunscreens and, according to an article by Ariel Schwartz on the Fast Company site, have some concerns,

Sunscreen is supposed to protect us from cancer, but a new report from the Environmental Working Group claims that many products don’t do what they’re supposed to. Some sunscreens contains ingredients that might even trigger skin tumors and lesions, according to the EWG’s 2010 Sunscreen Guide.

This year’s problem (from the EWG site),

A surge in exaggerated SPF claims above 50 and new disclosures about potentially hazardous ingredients, in particular recently developed government data linking the common sunscreen ingredient vitamin A to accelerated development of skin tumors and lesions.

If you plan to spend some time investigating  the EWG’s report on sunscreens, be prepared to receive a request to sign up (but it’s not required) before viewing the report.

UK strategy for investing in nanotech; new insight into titanium dioxide toxicology; creative nonfiction writing for scientists

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It sounds promising. UK strategy for nanotechnology business investment is the title of a news item on Nanowerk which outlines the UK Technology Board’s investment strategy. From the news item,

The UK’s Technology Strategy Board has developed a nanotechnology strategy document (pdf download) that sets out the processes the Technology Strategy Board will use to determine how it will invest in the nanotechnology space in a way that helps UK businesses to succeed on a global scale. It is based on the fundamental premise that the technologies likely to see the most success will be those that result in developing materials and devices with new functionality that address markets driven by society’s greatest challenges.

The item goes on to outline the specific areas (environment/energy; aging population, media) where investments will be made but gives no details about the amount of funding available or the source for funds. Curious, I checked out the UK Technology’s Board’s site.  No details to be found on the About Us pages although there is a link to a  Dept. of Business Innovation and Skills (presumably a government department). My guess is that these are government funds and the board has decided to be discreet about the connection. I’m not ready to draw any conclusions; I’m just noticing.

I’ve been following  (somewhat lazily) discussions around titanium dioxide particles (widely used in sunscreens) and their possible toxicology. Nanoparticles used in common household goods caused genetic damage in mice on Nanowerk sheds some new light on the subject. From the news item,

In the past, these TiO2 [titanium dioxide] nanoparticles have been considered non-toxic in that they do not incite a chemical reaction. Instead, it is surface interactions that the nanoparticles have within their environment- in this case inside a mouse – that is causing the genetic damage, [Robert] Schiestl [professor of pathology, radiation oncology and environmental health sciences at Jonsson Cancer Center at the University of California, Los Angeles] said. They wander throughout the body causing oxidative stress, which can lead to cell death. It is a novel mechanism of toxicity, a physicochemical reaction, these particles cause in comparison to regular chemical toxins, which are the usual subjects of toxicological research, Schiestl said. “The novel principle is that titanium by itself is chemically inert. However, when the particles become progressively smaller, their surface, in turn, becomes progressively bigger and in the interaction of this surface with the environment oxidative stress is induced,” he said.

I have posted about titanium dioxide in the past, this posting is the most relevant to this discussion as it contains a reference to some work by Japanese researchers who demonstrated that titanium dioxide cause genetic damage in mice. Presumably building on this work, the researchers at Jonsson Cancer Center have determined a possible mechanism for how the damage is caused.

This is the first time I’ve seen a study that doesn’t ‘shrink’ standard toxicology to the nanoscale. For example, “carbon nanotubes look like asbestos fibres so we should test to find out if they have the same effect on lungs. ” This makes sense and it should be done. At the same time, I’m glad to see that researchers are taking into account the fact that materials at the nanoscale behave in novel ways leading to novel forms of toxicology.

I was intrigued to read Dr. Kristen Kulinowki’s opinion piece in  Azonano’s Nanotechnology Thought Leaders Series … insights from the world’s leading players.  Her piece titled, Temptation, Temptation, Temptation: Why Easy Answers About Nanomaterial Risk are Probably Wrong, provided some valuable insights for me about the work that has been done to collect information about nanomaterials and their potentials risks while citing some useful resources.

Before you go to read the article there are a few things you might want to keep in mind. There are a couple themes that are not followed through so the piece jumps around, the tone is problematic, and the academic style is sometimes inserted into a more chatty blog style. All of which made reading the opinion piece a little more work for me.

I got the impression that Kulinowski did not put much effort into writing this piece, i.e. she tossed it off. The chatty, casual style (a creative writing technique) takes a lot more effort and practice and is much more difficult to pull off  than most people realize, especially when you’re writing nonfiction. (Yes, some people are naturals but even they need to work at it if they plan to continue long term.)

Nanotechnology, risk, science literacy and feelings; Canada’s Science and Technology Week 2009

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The Swiss-based Innovation Society has waded into the discussion about nanoparticles and sunscreens  in the wake of the Friends of the Earth (FOE) report (mentioned here yesterday August 20, 2009).

They point out something I forgot. Despite disagreeing on the “risk  profile,” both the Environmental Working Group (EWG) and FOE advise that nanomaterials should be labelled so that consumers can make informed choices,  (I’m not sure if I’ve seen the phrase risk profile or if I just coined it but I hope it makes sense in this context.) You can read about the Innovation Society’s perspective in their media release on Nanowerk News where they also offer links to the society’s August 2009 newsletter. You have to register to receive it and the form is in German as is the page which houses the public portion of the August 2009 newsletter. So, I’m not sure what language the newsletter is written in although most of what I saw on their site is in English.

As this last week has featured a published study about two women workers who died due to nanoparticle exposure and the FOE report, I’ve been reminded of the Cultural Cognition Project at Yale Law School (mentioned here on this blog last week). One of the conclusions in the paper I read about nanotechnology and risk is that people will make judgments about emerging technologies quickly, with little information, and in line with their feelings (affect), and cultural values. In the experimental investigation they found that increasing scientific literacy (i.e. giving the respondents more factual information about nanotechnology) did nothing or very little to alter someone’s opinion once it was formed.

I can agree with this conclusion as far as it goes. I’ve observed the same process of adhering to an opinion despite any evidence to the contrary in myself and others. I noted yesterday that the FOE report did not mention the EWG findings which, in my opinion, damages their credibility and bears out the conclusions made by the team at the Cultural Cognition Project.

There is one thing which niggles at me. Technologies have emerged before, e.g. electricity. At the time, during the 19th century, it was highly contested (do take a look at Carolyn Marvin’s book, When Old Technologies were New) . Very inflammatory language was used; all kinds of “experts” emerged; scientists engaged in lots of public outreach; there were deaths and injuries; and there were predictions that life on earth would end.  Seems familiar, doesn’t it? Still, electricity has become ubiquitous for much of the world. If cultural values and feelings trump science literacy, how did electricity become ubiquitous?

The Cultural Cognition Project team seemed to suggest in their paper that once opinions have been formed they are largely intractable. If that’s so, regardless of which group’s narrative gains dominance wouldn’t the other group continue to resist? (Note: the Amish opted out from using electricity.) History tells us otherwise.

I am getting ready for my presentation at the International Symposium on Electronic Arts (ISEA) so y9u may find that my posting schedule is interrupted. Happy weekend and here are a few final nuggets,

The Government of Canada, in the person of Rona Ambrose, Minister of Labour, has recognized Quantium Technologies (Edmonton, Alberta) for its innovation in the areas of “linking scientific research to commercialization, jobs and economic growth.” More can be found  in the media release on Nanowerk News.

Nanowerk News has also published a guide to the materials on their site, 10 things you should know about nanotechology. I highly recommend checking this out. Go here.

Canada’s 2009 Science and Technology Week will take place Oct. 16 – 25, 2009 (seems more like 10 days to me). You can check out the currently scheduled events (I’m sure this will be updated) for your province here,

There’s an interesting  story about the first copyright trial in 6th Century Ireland here on Techdirt.

Friends of the Earth and sunscreens; update on RUSNANO

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In a bit of interesting timing given that it’s on the heels of the publication of a study about two tragic deaths which are being attributed to exposure to nanoparticles, the Friends of the Earth (FOE) organization has released a report titled Nano-Sunscreens: Not Worth the Risk.The media release can be found on Azonano or Nanowerk News.

I have read the report (very quickly) and noted that they do not cite or mention the recently released report on the same topic by the Environmental Working Group (EWG) which stated that after an extensive review of the literature, there was no evidence that the titanium dioxide or zinc oxide nanoparticles used in sunscreens were dangerous. (posting here).

Shortly after the EWG report’s release, a new study (which I mentioned here … if you are inclined, do read the comments as some additional points about reading research critically are brought out)  suggested concerns based on the work of researchers in Japan.  The new study from Japan is cited in the Friends of the Earth report.

While the overall tone of the FOE report is fairly mild (they suggest precaution) they cite only a few studies supporting their concern and they damage their credibility (in my book) by ignoring a report from a well respected group that reluctantly admitted that there is no real cause for concern about nanoparticles in sunscreens based on the current evidence. FOE didn’t have to agree with the EWG’s conclusions but some counter-argument or discussion suggests that they don’t have a counter-argument or that they will ignore any opinions, and in the EWG case it’s based on evidence, contrary to their own.

More about this tomorrow when I tie it into science literacy, critical thinking, affect (feelings), and values.

Meanwhile, RUSNANO (Russian Corporation of Nanotechnologies) has announced $1.25B US  (40billion rubles) of investment will be approved this year. I blogged (here) about RUSNANO when their executives visited Canada with an eye to investing in Canadian nanotechnology companies. I will be eagerly waiting to find out if RUSNANO has followed up with investments in Canadian nanotechnology.

Flies carry nanoparticles; EPA invites comments; scientific collaboration in virtual worlds

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A new study is suggesting that flies exposed to nanoparticles in manufacturing areas or other places with heavy concentrations could accumulate the particles on their bodies and transport them elsewhere. From the media release on Nanowerk News,

During the experiments, the researchers noted that contaminated flies transferred nanoparticles to other flies, and realized that such transfer could also occur between flies and humans in the future. The transfer involved very low levels of nanoparticles, which did not have adverse effects on the fruit flies.

It makes perfect sense when you think about it. Flies pick up and transport all manner of entities so why wouldn’t they pick up nanoparticles in their vicinity?

In other news, the US Environmental Protection Agency (EPA) has asked for comments on case studies of nanoscale titanium dioxide in water treatment and sunscreens. Presumably you have to be a US citizen to participate. For more information on the call for comments, check out this item on Nanowerk News. From the item,

EPA is announcing a 45-day public comment period for the draft document, Nanomaterial Case Studies: Nanoscale Titanium Dioxide in Water Treatment and Topical Sunscreen (External Review Draft), as announced in the July 31, 2009 Federal Register Notice. The deadline for comments is September 14, 2009.

Yesterday, I came across an announcement about scientific collaboration in a virtual world (specifically Second Life). It’s the first professional scientific organization, Meta Institute for Computational Astrophysics (MICA), based entirely in a virtual world.

This idea contrasts somewhat with the NanoLands concept from the National Physical Laboratory in the UK where an organization with a physical location creates a virtual location. (You can see my interview with Troy McConaghy, part of the original NanoLands design team, here.)  The project blog seems to have been newly revived and you can find out more about NanoLands and their latest machinima movies. (If you want to see the machinima, you need a Second Life account.)

What I found particularly interesting about MICA is this bit from their media release on Physorg.com,

In addition to getting people together in a free and convenient way, virtual worlds can offer new possibilities for scientific visualization or “visual analytics.” As data sets become larger and more complex, visualization can help researchers better understand different phenomena. Virtual worlds not only offer visualization, but also enable researchers to become immersed in data and simulations, which may help scientists think differently about data and patterns. Multi-dimensional data visualization can provide further advantages for certain types of data. The researchers found that they can encode data in spaces with up to 12 dimensions, although they run into the challenge of getting the human mind to easily grasp the encoded content.

Shades of multimodal discourse! More tomorrow.

More titanium dioxide news; the 5th anniversary of the Royal Society’s Report on Nanotechnology; Copyright in Canada

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While titanium dioxide particles in sunscreens are considered safe (see my blog posting here), there is a new study which suggests concerns. A study was done in Japan on pregnant mice who were injected with titanium dioxide nanoparticles. The results suggest that the particles affected brain development in the foetuses. (The media release is located at Nanowerk News here.) My questions since I haven’t looked at the study are this:  Where was the injection site? What was the concentration of  titanium dioxide nanoparticles in the solution? Where several concentrations used or only one? (After all, a lot of medicines are poison if taken in the wrong dosage or misapplied [taken internally instead of externally].)

Still on the titanium dioxide trail, there’s a study by researchers in Switzerland which suggests that nanowires and nanotubes made of titanium dixoide are toxic. There’s an article by Miichael Berger here on Nanowerks. From Berger’s article,

One of the complications of nanotoxicology is that the toxicity of a specific nanomaterial cannot be predicted from the toxicity of the same material in a different form.

…

“TiO2 nanoparticles are widely used as UV blockers in sunscreens” says Arnaud Magrez [researcher]. “Their cytotoxicity has been tested before and they were found to be rather non-toxic. Our new study shows that TiO2 based nanofilaments, however, can be quite toxic. The geometry of nanoparticles appears to play a crucial role in cytotoxicity. Furthermore, the toxicity can be enhanced by the presence of defects on the nanofilament surface, resulting from chemical treatment.”

Both of these studies highlight why more research needs to be done. A comment which is made in an entirely different context by Dr. Andrew Maynard in his essay commemorating the anniversary of the Royal Society/Royal Academy of Engineering 2004 report on nanotechnologies. Maynard’s essay is the foreword to a report, 5 years on – a beacon or just a landmark? Reflections on the 2004  Royal Society/Royal Academy of Engineering report into nanotechnologies – what was its impact and what is its legacy? published by the Responsible Nano Forum. Maynard’s essay can be read here on his 2020 Science blog and the report can be found here. From Maynard’s essay,

At the time, concerns were mounting over possible new risks associated with creating materials and devices at the nanoscale, and how these would affect the technology’s development.  The previous year, Michael Crichton’s book Prey had sent the nanotech community into a tizzy over a speculative public backlash against the emerging science and technology.  And researchers were beginning to reveal hints that novel nanoscale materials could also affect humans and the environment in unconventional ways—getting to places and causing harm on a scale that belied their small size.

Do read it if you have the time. Maynard’s perspective is both historical and contemporary.

And now for something which concerns me when writing this blog, copyright. Since this blog isn’t profitmaking and I give attribution and encourage people to visit the sites and blogs I quote from, I’ve considered what I do ‘fair use’. If you’ve been following the copyright discussion, you know ‘fair use’ is being debated fiercely as is intellectual property law which includes copyright, patents, and trademarks.

After a rather disastrous attempt to introduce new copyright legislation (last fall I think), the Canadian government has launched a public consultation process. (I too was surprised to find out about it.) The roundtable meeting in Vancouver took place about 10 days ago. There will be roundtable meetings  elsewhere and two town hall meetings (where the public will be invited). If you’re a member of the public who’s lucky enough to live in either Toronto or Montreal, you can have your say in real time. The rest of us can participate online here at the Copyright Counsultations website. You do have to register to participate. The Vancouver roundtable meeting has been transcribed and is available online here and the trasncript for the Calgary roundtable is here.

Nanoparticles in sunscreens and other places

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Whodathunkit? Sunscreens with titanium dioxide and zinc oxide nanoparticles are safer and more effective than the sunscreens without them. Thanks to Andrew Maynard at 2020 Science there’s an overview of the results, the study, and, most importantly, the source for the study’s report. Maynard (chief science advisor for the Project on Emerging Nanotechnologies) also offers a few comments about environmental and health concerns and the need for more research into the use of nanoparticles in cosmetic/beauty products.

The EWG (Environmental Working Group) is, according to Maynard, not usually friendly to industry and they had this to say about their own predisposition prior to reviewing the data (from EWG),

When we began our sunscreen investigation at the Environmental Working Group, our researchers thought we would ultimately recommend against micronized and nano-sized zinc oxide and titanium dioxide sunscreens. After all, no one has taken a more expansive and critical look than EWG at the use of nanoparticles in cosmetics and sunscreens, including the lack of definitive safety data and consumer information on these common new ingredients, and few substances more dramatically highlight gaps in our system of public health protections than the raw materials used in the burgeoning field of nanotechnology. But many months and nearly 400 peer-reviewed studies later, we find ourselves drawing a different conclusion, and recommending some sunscreens that may contain nano-sized ingredients.

There is a proviso to their evaluation and it’s standard science talk. The conclusion is based on the current evidence, which means that someone might or might not discover a problem tomorrow.

I commented about an article on sunscreens, which covered some material about nanoparticle concerns, in a fashion magazine here.

Meanwhile, the concern over silver nanoparticles continues. The Australian branch of Friends of the Earth (FOE) has issued a report urging caution. From the Australian Broadcasting Corporation article by Anna Saleh

Associate Professor Tom Faunce, an expert in the medical and regulatory aspects of nanotechnology at the Australian National University in Canberra says because nano-silver is very useful in medicine, he does not support the call for a total moratorium on nano-silver.

But he thinks there does need to be some restraint on its use.

“There is accumulating evidence now that if nano-silver use is left unrestrained and it enters the waterways in large amounts, this will be dangerous to the environment,” says Faunce.

I am relieved to hear about the nanoparticles in sunscreens and not surprised about the caution regarding silver nanoparticles. After scanning the internet for information about nanotechnology over the last 2.5 years or so, there are two major areas of concern (from my neophyte’s perspective), silver nanoparticles and carbon nanotubes (the ones that resemble asbestos fibres).

Regardless of the EWG’s conclusions, I’m pretty sure there are people out there who will reject the findings because they don’t like the idea of nanoparticles in anything, anywhere, anytime.

Tomorrow a little nano haiku courtesy of NISE network.