Tag Archives: Anders Baun

Silver nanoparticles: we love you/we hate you

We seem to have a love/hate affair with silver nanoparticles. Long recognized as biocides capable of killing bacteria, silver nanoparticles are used both in hospital settings and in sports wear. As the use of silver nanoparticles increases, there are concerns about unintended consequences to the environment and to human health. An Apr. 12, 2013 news item on Nanowerk highlights some research done in Europe in 2011 (Note: Links have been removed),

As part of an EU funded project called Prosuite, Walser [Tobias Walser, researcher at the Institute for environmental engineering at the Swiss Federal Institute of Technology Zürich {ETH}] and colleagues analysed the environmental impact of nanosilver T-shirts during their entire life cycle, from raw material extraction to end-of-life disposal (“Prospective Environmental Life Cycle Assessment of Nanosilver T-Shirts”). This, according to Walser, is the first of its kind for a nanomaterial. The scientists found that the T-shirt’s environmental impact during use would be reduced if they are washed less often than conventional ones, due to their antimicrobial properties. This would even compensate for a slightly higher climate footprint during production. Walser explains: “In comparison to all toxic releases during the life cycle of a T-shirt, the toxic releases from nanosilver from washing appear to be of minor relevance.” [emphasis mine]

The Apr. 11, 2013 article by Constanze Böttcher for Youris.com, which originated the news item, expands on the theme of toxicity, nanosilver, and wastewater (Note: A link has been removed),

Previous studies looked at single impacts of antibacterial textiles. For example, scientists found that nanosilver leaches into the wastewater during washing. According to other studies, this silver may not be that harmful to the environment because it is transformed into a nearly insoluble substance called silver sulphide in wastewater treatments. A study published by the Danish Environmental Protection Agency in 2012 did not find “specific risks” to health or environmental effects of nanosilver textiles available in Denmark.

This finding contrasts with more recent research at Duke University’s CEINT (Center for Environmental Implications of Nanotechnology) mesocosm project where a study did point to adverse responses (noted in my Feb. 28, 2013 posting where I highlighted two nanosilver environmental studies, a Finnish/Estonian research project and the CEINT project),

In experiments mimicking a natural environment, Duke University researchers have demonstrated that the silver nanoparticles used in many consumer products can have an adverse effect on plants and microorganisms.

The main route by which these particles enter the environment is as a by-product of water and sewage treatment plants. [emphasis] The nanoparticles are too small to be filtered out, so they and other materials end up in the resulting “sludge,” which is then spread on the land surface as a fertilizer.

The researchers found that one of the plants studied, a common annual grass known as Microstegium vimeneum, had 32 percent less biomass in the mesocosms treated with the nanoparticles. Microbes were also affected by the nanoparticles, Colman [Benjamin Colman, a post-doctoral fellow in Duke’s biology department and a member of the Center for the Environmental Implications of Nanotechnology (CEINT)] said. One enzyme associated with helping microbes deal with external stresses was 52 percent less active, while another enzyme that helps regulate processes within the cell was 27 percent less active. The overall biomass of the microbes was also 35 percent lower, he said.

As I’ve suggested before, analysing the impact that new products and materials may have on the environment and on our health is a complex process.  From Böttcher’s 2013 article (Note: Links have been removed),

Some experts are concerned about their environmental risks, however. The study “is very relevant” because it “gives a fingerprint” about the impact of such T-shirts, Anders Baun says. But the professor in risk assessment of nanomaterials at the department of environmental engineering at the Technical University of Denmark, based in Lyngby, considers it “a bad idea to distribute silver in the environment”. He points to a study that found evidence for nanosilver accumulating in the food web based on a study of plants and animals of an experimental wetland environment. Moreover, he says, it is unknown how the coating of nanosilver influences its environmental behaviour. Baun has previously criticised the European policies regarding nanosilver and is currently enrolled in a scientific committee on the topic as invited expert. The expert group will publish its opinion later this year, he says.

There’s also the possibility that bacteria will develop resistance with increased use of silver nanoparticles in medical environments and in sportswear and in other applications.

For those who want to conduct their own investigations, here’s a link to and a citation for Walser’s 2011 paper,

Prospective Environmental Life Cycle Assessment of Nanosilver T-Shirts by Tobias Walser, Evangelia Demou, Daniel J. Lang, and Stefanie Hellweg.  Environ. Sci. Technol [Environmental Science and Technology], 2011, 45 (10), pp 4570–4578 DOI: 10.1021/es2001248 Publication Date (Web): April 20, 2011
Copyright © 2011 American Chemical Society

This paper is open access.

A description of PROSUITE (PROspective SUstaInability assessment of TEchnologies project) can be found here and the PROSUITE project website can found here.

ETA Apr. 18, 2013: An Apr. 18, 2013 news item (Barely any nanosilver from consumer products in the water) on Nanowerk provides some insight into why at least one European country views the presence of silver nanoparticles in sewage sludge without any particular alarm,

The study did not examine what happens to nanosilver in the sewage sludge thereafter. In Switzerland, it is not permissible to use sewage sludge on farmland, and most of the sludge is therefore burned. [emphasis mine] The heavy metals separated in this process should not be released into the environment in large quantities.

Here’s a link to and citation for the Swiss study,

Fate and transformation of silver nanoparticles in urban wastewater systems by Ralf Kaegia, Andreas Voegelina, Christoph Orta, Brian Sinneta, Basilius Thalmanna, Jasmin Krismerb, Harald Hagendorferc, Maline Elumelua, and Elisabeth Muellerd. Water Research, http://dx.doi.org/10.1016/j.watres.2012.11.060 Available online 26 March 2013

The article is behind a paywall.

Toxicology convo heats up: OECD releases report on inhalation toxicity testing and Nature Nanotechnology publishes severe critique of silver toxicity overanalysis

This has to be one of the rawest reports I’ve seen and that’s not a criticism. The OECD (Organization for Economic Cooperation and Development) has released no. 35 in its Series on the Safety of Manufactured Nanomaterials titled, INHALATION TOXICITY TESTING: EXPERT MEETING ON POTENTIAL REVISIONS TO OECD TEST GUIDELINES AND GUIDANCE DOCUMENT.

This report is the outcome of a meeting which took place in fall 2011 according to the July 4, 2012 news item on Nanowerk,

The expert meeting on Inhalation Toxicity Testing for Nanomaterials was held on 19-20 October 2011 in The Hague, hosted by the Netherlands, with the aim of discussing the results of the OECD Sponsorship Programme (under the responsibility of SG3) on this specific topic and addressing issues relevant to inhalation toxicity. Fifty experts from the WPMN as well as the OECD Working Group of the National Coordinators for the Test Guidelines programme (WNT) participated in the meeting.

This is a partial list of recommendations from the report,

Recommendations raised by the speakers for the discussion

7. Various recommendations were raised by the speakers that served as points for discussion. These recommendations do not necessarily reflect a general agreement. …

• “Provide explicit guidance for the generation of aerosols (sample preparation) based on the exposure scenario”. Hans Muijser

• “Generation of a test atmosphere should have workplace characteristics, but should be adapted to adjust for rodent respirability”. Günter Oberdörster

• “A choice for a dry aerosol or a liquid aerosol should depend on the given test substance and planned test approach (hazard- or risk driven)”. Otto Creutzenberg

• “Aerosol characterization should include size distribution, mass, number and morphology of the material”. Günter Oberdörster

• “Mass concentration is not sufficient for comparison of nanomaterials of the same chemical composition”. Flemming Cassee

• “Dry powders will appear as agglomerate upon aerosolization, which needs to be addressed in the sample preparation guidelines”. Flemming Cassee

• “Dissolution behaviour of the test substance should be assessed in physiological fluids mimicking various lung-specific pH ambiences (neutral, acid)”. Otto Creutzenberg

• “Data analysis should include interpretation of aerosol characteristics, NOAEL, risk assessment implications, mode of action and a strategy for dosimetric extrapolation to humans. The inclusion of biokinetic data is important”. Günter Oberdörster

• “Include biokinetics in the guidance, since different distribution patterns in the whole organism are likely dependent on physicochemical characteristics of nanoparticle aerosols and the dose at the target site will therefore be different. This will allow the assessment of accumulation of nanomaterials in the body at low exposure levels and long-term exposure. A way to perform it is by radiolabelled materials, chemical elemental analysis to determine organ concentrations and transmission electron microscopy”. Wolfgang Kreyling. Others who have suggested inclusion of biokinetics or recognized the importance were Otto Creutzenberg, Frieke Kuper, Günter Oberdörster and David Warheit. (p. 13)

You actually see who made the recommendations! Speakers discussed carbon nanotubes, titanium dioxide, cerium oxide, zinc oxide and more, all of which you can read about in summary form in this 38 pp. report.

Meanwhile, Nature Nanotechnology has published an incendiary commentary about nanosilver and the latest request by the European Commission for another study.  Michael Berger has devoted a July 4, 2012 Nanowerk Spotlight article to the commentary,

A commentary by Steffen Foss Hansen and Anders Baun in this week’s Nature Nanotechnology (“When enough is enough”  [behind a paywall]) pointedly asks “when will governments and regulatory agencies stop asking for more reports and reviews, and start taking regulatory action?”

Hansen and Baun, both from the Technical University of Denmark’s Department of Environmental Engineering, take issue with yet another scientific opinion on nanosilver that has been requested by the European Commission in late 2011: “SCENIHR – Request for a scientific opinion on Nanosilver: safety, health and environmental effects and role in antimicrobial resistance” (pdf). Specifically, the EC wants SCENIHR to answer four questions under the general heading of ‘Nanosilver: safety, health and environmental effects, and role in antimicrobial resistance’.

“Most of these questions – and possibly all of them – have already been addressed by no less than 18 review articles in scientific journals, the oldest dating back to 2008, plus at least seven more reviews and reports commissioned and/or funded by governments and other organizations” Hansen tells Nanowerk. “Many of these reviews and reports go through the same literature, cover the same ground and identify many of the same data gaps and research needs.”

Here’s a prediction from Hansen and Baun as to what will be in the next report due in 2013  (from the Nature Nanotechnology commentary When enough is enough in 7, 409–411 (2012) published online  July 1, 2012 [Note: I have removed links and footnotes]),

… we predict that the SCENIHR’s upcoming review will consist of five main sections summarizing: the properties and uses of nanosilver; human and environmental toxicity; microbial resistance; risk assessment; and research needs. We also predict that the SCENIHR’s report will say something along the following lines: “Nanosilver is reportedly one of the most widely used nanomaterials in consumer products today but the scale of production and use is unknown. The antibacterial properties of nanosilver are exploited in a very diverse set of products and applications including dietary supplements, personal care products, powdered colours, textile, paper, kitchenware and food storage.” And like many previous reviews and reports, the new report is likely to cite the Consumer Product Inventory maintained by the Project on Emerging Nanotechnologies.

We acknowledge that answering the question of how to regulate the use of nanosilver is not easy given the different views of the different stakeholders in this debate and the complex regulatory landscape associated with the many applications of nanosilver. …

Arguably, we all want that the pros and cons of regulatory policy options be based on the best available science while taking broader socio-economical and ethical aspects into consideration before deciding on the appropriate regulatory measures concerning human and environmental exposure to nanosilver. Although it is common for independent scientific experts to be commissioned to gather, analyse and review the available scientific information, and to provide recommendations on how to address a given risk, we do not see the need for further reviews. It is time for the European Commission to decide on the regulatory measures that are appropriate for nanosilver. These measures should then be implemented wholeheartedly and their effectiveness monitored.

I predict this commentary will provoke some interesting responses and I will try to add the ones I can find to this posting as they become available.

ETA July 6, 2012: Dexter Johnson weighed in with his July 5, 2012 posting (Note: I have removed a link),

What may make the matter even worse is that we may already have a pretty substantial framework—in the US, at least—on which to base nanosilver regulations, which dates back to the 1950s. It concerned what was called at the time collodial silver, which is essentially what today is called nanosilver.

But getting back to current stagnant state of affairs, it’s hard to know exactly what’s causing the paralysis. It could be concern over implementing regulations in a depressed economy, or just a fear of taking a position. But in both these instances, the lack of action is making the situation worse. …

Special issue on nanotechnology and regulations from EJLT

The European Journal of Law and Technology (EJLT) is featuring 15 articles on the theme of nanotechnology and regulations in a special issue. From the Dec. 12, 2011 news item on Nanowerk,

The issue contains 15 contributions that canvass some of the most pressing philosophical, ethical and regulatory questions currently being debated around the world in relation to nanotechnologies and more specifically nanomaterials.

The EJLT is an open access journal so you can view these articles or any others that may interest you. Here’s the Table of Contents for the special issue,

Table of Contents

Editorial

Editorial
Philip Leith, Abdul Paliwala

Introduction to the Special Issue

Why the elephant in the room appears to be more than a nano-sized challenge
Joel D’Silva, Diana Meagan Bowman

Nano Technology Special Edition

Decision Ethics and Emergent Technologies: The Case of Nanotechnology
David Berube
Justice or Beneficence: What Regulatory Virtue for Nano-Governance?
Hailemichael Teshome Demissie
Regulating Nanoparticles: the Problem of Uncertainty
Roger Strand, Kamilla Lein Kjølberg
Complexities of labelling of nanoproducts on the consumer markets
Harald Throne-Holst, Arie Rip
Soft regulation and responsible nanotechnological development in the European Union: Regulating occupational health and safety in the Netherlands
Bärbel Dorbeck-Jung
Nanomaterials and the European Water Framework Directive
Steffen Foss Hansen, Anders Baun, Catherine Ganzleben
The Proposed Ban on Certain Nanomaterials for Electrical and Electronic Equipment in Europe and Its Global Security Implications: A Search for an Alternative Regulatory Approach
Hitoshi Nasu, Thomas Faunce
The Regulation of Nano-particles under the European Biocidal Products Directive: Challenges for Effective Civil Society Participation
Michael T Reinsborough, Gavin Sullivan
Value chains as a linking-pin framework for exploring governance and innovation in nano-involved sectors: illustrated for nanotechnologies and the food packaging sector
Douglas Robinson
Food and nano-food within the Chinese regulatory system: no need to have overregulation.Less physicality can produce more power.
Margherita Poto
Regulation and Governance of Nanotechnology in China: Regulatory Challenges and Effectiveness
Darryl Stuart Jarvis, Noah Richmond
How Resilient is India to Nanotechnology Risks? Examining Current Developments, Capacities and an Approach for Effective Risk Governance and Regulation
Shilpanjali Deshpande Sarma
Toward Safe and Sustainable Nanomaterials: Chemical Information Call-in to Manufacturers of Nanomaterials by California as a Case Study
William Ryan, Sho Takatori, Thomas Booze, Hai-Yong Kang
De minimis curat lex: New Zealand law and the challenge of the very small
Colin Gavaghan, Jennifer Moore

I notice that the last article was authored by the same people who produced a review of New Zealand’s nanotechnology regulatory framework in Sept. 2011. The Science Media Centre of New Zealand noted this in a Sept. 6, 2011 article about the review,

The “Review of the Adequacy of New Zealand’s Regulatory Systems to Manage the Possible Impacts of Manufactured Nanomaterials” by Colin Gavaghan (in Dunedin) and Jennifer Moore (in Wellington) lists three possible levels of regulatory gaps, but points to a lack of consensus on just what constitutes a “gap”.

The authors note where such nanomaterials are not covered by existing regulation, and where these regulations are triggered by the presence of the nanomaterials. They focus on first and second generation products and say that as nanomaterials evolve, more work will need to be done on regulation.

“Some reviews of this topic have suggested that subsequent generations of nanotechnologies are likely to present a much more significant challenge to existing regulatory structures,” the authors say.

The EJLT special issue looks like it has a pretty interesting range of articles representing nanotechnology and regulations in various jurisdictions. I’m thrilled to see a couple of articles on China, one on India, and, of course, the piece on New Zealand as I don’t often find material on those countries. Thank you EJLT!

Site remediation and nano materials; perspectives on risk assessment; Leonardo’s call for nano and art; a new nano art/science book

The Project on Emerging Nanotechnologies (PEN) is holding an event on site remediation on Feb. 4, 2010 (12:30 pm to 1:30 pm EST). From the news release,

A new review article appearing in Environmental Health Perspectives (EHP) co-authored by Dr. Todd Kuiken, Research Associate for the Project on Emerging Nanotechnologies (PEN), Dr. Barbara Karn, Office of Research and Development, U.S. Environmental Protection Agency and Marti Otto, Office of Superfund Remediation and Technology Innovation, U.S. Environmental Protection Agency focuses on the use of nanomaterials for environmental cleanup. It provides an overview of current practices; research findings; societal issues; potential environment, health, and safety implications; and possible future directions for nanoremediation. The authors conclude that the technology could be an effective and economically viable alternative for some current site cleanup practices, but potential risks remain poorly understood.

PEN’s Contaminated Site Remediation: Are Nanomaterials the Answer? features the EHN article’s authors  Kulken, Karn, and Otto on a panel with David Rejeski, PEN’s executive director moderating. PEN also has a map detailing almost 60 sites (mostly in the US, 2  in Canada, 4 in Europe, and 1 in Taiwan) where nanomaterials are being used for remediation.  More from the news release,

According to Dr. Kuiken, “Despite the potentially high performance and low cost of nanoremediation, more research is needed to understand and prevent any potential adverse environmental impacts, particularly studies on full-scale ecosystem-wide impacts. To date, little research has been done.”

In its 2004 report Nanoscience and nanotechnologies: opportunities and uncertainties, the British Royal Society and Royal Academy of Engineering recommended that the use of free manufactured nanoparticles be prohibited for environmental applications such as remediation until further research on potential risks and benefits had been conducted. The European Commission’s Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) called for further risk research in 2005 while acknowledging environmental remediation technology as one of nanotechnology’s potential benefits.

If you wish to attend in person (i.e. you are in Washington, DC), you are asked to RSVP here (they provide a light lunch starting at 12 pm) or you can watch the webcast (no RSVP necessary and I will put up a link to the webcast closer to the date).

On the topic of risk, Michael Berger has written an in depth piece about a recently published article, Redefining research risk priorities for nanomaterials, in the Journal of Nanoparticle Research. From Berger’s piece,

While research in quantitative risk characterization of nanomaterials is crucially important, and no one advocates abandoning this approach, scientists and policy makers must face the reality that many of these knowledge gaps cannot be expected to be closed for many years to come – and decision making will need to continue under conditions of uncertainty. At the same time, current chemical-based research efforts are mainly directed at establishing toxicological and ecotoxicological and exposure data for nanomaterials, with comparatively little research undertaken on the tools or approaches that may facilitate near-term decisions.

In other words, there’s a big lag between developing new products using nanomaterials and the research needed to determine the health and environmental risks associated both with the production and use of these new materials. The precautionary principle suggests that we not produce or adopt these products until we are certain about risks and how to ameliorate and/or eliminate them. That’s an impossible position as we can never anticipate with any certainty what will happen when something is released to the general public or into the environment at large.  From Berger’s piece,

In their article, [Khara Deanna] Grieger [PhD student at Technical University of Denmark (DTU)], Anders Baun, who heads DTU’s Department of Environmental Engineering, and Richard Owens from the Policy Studies Institute in the UK, argue that there has not yet been a significant amount of attention dedicated to the field of timely and informed decision making for near term decisions. “We see this as the central issue for the responsible emergence of nanotechnologies” says Grieger.

Getting back to site remediation using nanomaterials, since it’s already in use as per the map and the authors state that there hasn’t been enough research into risks, do we pull back and adopt the precautionary principle or do we proceed as intelligently as possible in an area where uncertainty rules? That’s a question I will continue to explore as I get my hands on more information.

On a completely different nano front, the Leonardo magazine has issued a call for papers on nano and art,

2011 is the International Year of Chemistry! To celebrate Leonardo is seeking to publish papers and artworks on the intersections of chemistry,
nanotechnology and art for our on-going special section on nanotechnology and the arts. Since its inception nanotech/science has been intimately connected to chemistry; fullerenes, nanoputians, molecular machines, nano-inorganics and self-assembling molecular systems all spring from the minds and labs of chemists, biochemists and chemical engineers. If you’re a nano-oriented chemist who is serious about art, an artist working on the molecular level, or a chemical educator exploring the mysteries of nano through the arts we are especially seeking submissions from you.

You can send proposals, queries, and/or manuscripts to the Leonardo editorial office: leonardomanuscripts@gmail.com. You can read more about the call for papers here at Leblogducorps or you can go here to the Leonardo online journal.

Meanwhile, Andrew Maynard at 2020 Science is posting about a new book which integrates art work in an attempt to explain nanotechnology without ever mentioning it. From Andrew’s posting,

How do you write a book about something few people have heard off, and less seem interested in?  The answer, it seems, is to write about something else.

Felice Frankel and George Whitesides have clearly taken this lesson to heart. Judged by the cover alone, their new book “No Small Matter:  Science at the Nanoscale” is all about science in the Twilight zone of the nanoscale

– where stuff doesn’t behave in the way intuition says it should.

Drat! I can’t make the indent go away. At any rate, do visit 2020 as Andrew to read more from this posting and at least one other where he has gotten permission to excerpt parts of the book (text and images).