An Oct. 13, 2017 news item on Nanowerk announced news test guidelines from the Organization for Cooperation and Economic Development (OECD),
The OECD has released a first set of Test Guidelines developed specifically for nanomaterials, in response to their increased production and usage. The guidelines will help standardise the way countries test the safety of manufactured nanomaterials, whose near atomic-sized particles mean they may require more than regular chemical testing to understand their impact on health and the environment.
An Oct. 13, 2017 OECD press release (received via email), which originated the news item, provides more detail,
Additionally, updates to two existing Test Guidelines for inhalation toxicity studies (Guideline 412 and Guideline 413) mean they can now be used to determine the toxicity of inhaled nanomaterials.
The use of nanomaterials has skyrocketed of late, with manufacturers using them to improve performance in everything from tennis rackets to deodorant, yet nanoparticles can more easily penetrate skin, cells and the environment than larger compounds, and the increased likelihood of them entering the environment and human and animal bodies has raised concerns over their safety.
Working for 45 years to standardise methodologies for hazard testing and assessment, the OECD has produced over 160 harmonised test methods for determining physical and chemical properties, the effects of chemicals on health, wildlife and the environment, the efficacy of biocides and the chemistry of pesticide residues.
OECD Test Guidelines are used on a daily basis to test and assess the safety of industrial chemicals, pesticides and personal care products. They are part of the OECD’s Mutual Acceptance of Data programme, which saves over 150 million euros a year for its 42 signatory countries by avoiding duplication, as test data generated in one country is accepted by others having the same data requirement.
Journalists can download the new Test Guidelines for free on the OECD iLibrary at the links below using the OECD’s media log-in and password (available to media on request) or by email on request.
S.NET once stood for Society for the Study of Nanoscience and Emerging Technologies and then the name started changing with the most recent being, Society of the Studies of New and Emerging Technologies. As I noted in my 2017 end-of-year comments (Dec. 30, 2017 posting), the nano blogosphere is also shifting as nanotechnology is being absorbed into and enables other scientific and technical efforts.
S.NET is celebrating its 10th year at their annual meeting, which will be held in Maastricht (Netherlands). Here’s their call for papers,
2018 Annual S.NET Meeting
Image: Geert Budenaerts, Wikimedia
CALL for PAPERS.
The 10th annual S.NET meeting will take place June 25-27, 2018 at the Faculty of Arts and Social Science, Maastricht University, The Netherlands. The theme is Anticipatory Technologies: Data and Disorientation.
S.NET invites contributions to the tenth annual meeting of The Society for the Study of New and Emerging Technologies (S.NET), to be held at Maastricht University, the Netherlands, on June 25 – 27, 2018. The three-day conference will assemble scholars, practitioners and policy makers from around the world interested in the development and implications of emerging technologies.
S.NET is an international association that promotes intellectual exchange and critical inquiry about the advancement of new and emerging technologies in society. The aim of the association is to advance critical reflection from various perspectives on developments in a broad range of new and emerging fields, including, but not limited to, nanoscale science and engineering, biotechnology, synthetic biology, cognitive science, ICT and Big Data, and geo-engineering. Current S.NET board members are: Michael Bennett (chair), Marianne Boenink, Ana Delgado, Clare Shelley-Egan, Chris Toumey, Poonam Pandey, Christopher Coenen, Colin Milburn, Kornelia Konrad, Nora Vaage, Maria Belen Albornoz, and Ryan LaBar.
Conference Theme: Anticipatory technologies – data and disorientation
Any effort on new and emerging technologies unavoidably deals with the non-existing and the speculative. The future is permanently mobilized to promote decisions and policies regarding the science, technology and society nexus. Anticipatory technologies like predictive policing and preventive medicine promise to give us better epistemic access and practical control over the future. The basic irony, however, is that anticipatory technologies do not only increase data but also disorientation. Is the disorientation vis-á-vis the future in spite of the astonishing growth of data, or can it be a result of that growth? Does the growing control over future events in terms of risk make people more acutely aware of what they don’t control? Contributions are invited that explore existing ways in which the future is mobilized, technologically mediated, and economically exploited; that map the manifold ways it is contested both in discourse and in action; and that reflect on the extent to which new technologies ironically undermine our faith in the future.
Key note speakers
Prof Cyrus Mody is an historian of recent science and technology and has published on the history of nanotechnology and micro-electronics. He studies the commercialization of academic research, countercultural science and technology, and the longue durée of responsible research and innovation. He worked at Rice University, Texas, the NSF Center for Nanotechnology in Society and now has a chair at Maastricht University.
Prof Marjolein van Asselthas a strong profile on governance, risk and uncertainty in both academic and policy circles. Currently she is member of the Dutch Safety Board and was a member of the Scientific Council for Government Policy for many years. She has a Governance chair at Maastricht University.
Third key note speaker to be announced.
Themes, topics and conference strands for the 10th Annual Meeting
S.NET encompasses communities, perspectives, and methodologies from across the social sciences, humanities and natural sciences, and welcomes contributions from technology developers and other practitioners. The program committee invites contributions from the full breadth of disciplines, methodologies, and perspectives, as well as from applied, participatory, and practical approaches to studying these emerging fields. Regionally or internationally comparative perspectives are especially welcome. Possible themes and topics have been organized into one overarching conference theme and six ‘strands’. While applicants are asked to indicate the strand relevant to the topic of their paper, submissions dealing with themes or topics outside the present strands are also welcome.
R&D practices and the dynamics of new and emerging sciences and technologies
Research networks & collaborations, ways of organizing research & development, emerging research fields, practices of ‘doing’ new and emerging fields of science and technology, including historical and philosophical studies of these practices.
Innovation and the use of new and emerging sciences and technologies
Innovation networks and systems, commercialization, implications for industry structures, translation from lab to practice, application and use of products and other innovations, critical analyses of growth and consumption, including economic, social and cultural approaches of innovation processes.
Governance of newly emerging sciences and technologies
Regulations, anticipatory governance practices, risk assessment, risk concerns, (constructive) TA, forms of public participation and engagement, including critical evaluation of forms of governance.
Visions and cultural imaginaries of newly emerging sciences and technologies
Promises, expectations, visions, science fiction, imagination, socio – technical change, moral change, role of media, including assessments of such visions and analyses of their role in innovation processes.
Publics and their relations to newly emerging science s and technologies
Science communication, risk communication, public engagement, participation and discourses on NEST, science museums, informal science learning initiatives, including critical evaluation of such initiatives and the notion of ‘publics’.
Politics and ethics of new and emerging sciences and technologies
Responsible innovation, (in)equality, equity, development, global and social distribution of benefits and risks, sustainability, ‘soft’ and ‘hard’ impacts of emerging technologies, including theoretical perspectives on NEST and global developments.
How to apply
S.NET encourages proposals for individual papers, posters, traditional panels, roundtable discussions and other innovative formats. Abstracts should be approximately 250 words in length. Proposals for panel sessions should include a general introduction and abstracts of the separate contributions. Proposals should include the theme or strand to which the abstract/panel session is submitted. If an abstract fits more strands, or does not fit the existing strands, simply note that in your submission. The deadline for abstract submissions is March 2, 2018; send your abstract in PDF form to email@example.com. All submitters will be notified about the results of the review process by the end of April 2018. Details of the submission process are available online: www.maastrichtsts.nl/snet.
The local organizing committee
Tsjalling Swierstra, Harro van Lente, Nora Vaage, Conor Douglas, Danielle Shanley, Darian Meacham, Cindy van Montfoort, Jacqueline Graff.
Maastricht is an ancient Roman city of some 120.000 inhabitants in the south of The Netherlands and has a beautiful medieval inner-city. Generally known as the venue of the Treaty of Maastricht, it has a distinctly international orientation. Maastricht can easily be reached by plane, train and car. Maastricht University is internationally oriented; its students come from all over the world. The Faculty of Arts and Social Sciences (FASoS) is located in the centre of Maastricht.
Researchers in Sweden suggest plastic nanoparticles may cause brain damage in fish according to a Sept. 25, 2017 news item on phys.org,
Calculations have shown that 10 per cent of all plastic produced around the world ultimately ends up in the oceans. As a result, a large majority of global marine debris is in fact plastic waste. Human production of plastics is a well-known environmental concern, but few studies have studied the effects of tiny plastic particles, known as nanoplastic particles.
“Our study is the first to show that nanosized plastic particles can accumulate in fish brains”, says Tommy Cedervall, a chemistry researcher at Lund University.
The Lund University researchers studied how nanoplastics may be transported through different organisms in the aquatic ecosystem, i.e. via algae and animal plankton to larger fish. Tiny plastic particles in the water are eaten by animal plankton, which in turn are eaten by fish.
According to Cedervall, the study includes several interesting results on how plastic of different sizes affects aquatic organisms. Most importantly, it provides evidence that nanoplastic particles can indeed cross the blood-brain barrier in fish and thus accumulate inside fish’s brain tissue.
In addition, the researchers involved in the present study have demonstrated the occurrence of behavioural disorders in fish that are affected by nanoplastics. They eat slower and explore their surroundings less. The researchers believe that these behavioural changes may be linked to brain damage caused by the presence of nanoplastics in the brain.
Another result of the study is that animal plankton die when exposed to nanosized plastic particles, while larger plastic particles do not affect them. Overall, these different effects of nanoplastics may have an impact on the ecosystem as a whole.
“It is important to study how plastics affect ecosystems and that nanoplastic particles likely have a more dangerous impact on aquatic ecosystems than larger pieces of plastics”, says Tommy Cedervall.
However, he does not dare to draw the conclusion that plastic nanoparticles could accumulate in other tissues in fish and thus potentially be transmitted to humans through consumption.
“No, we are not aware of any such studies and are therefore very cautious about commenting on it”, says Tommy Cedervall.
Researchers from the Mayo Clinic have proposed that negative cellular responses to titanium-based nanoparticles released from metal implants interfere in bone formation and resorption at the site of repair, resulting in implant loosening and joint pain. [emphasis mine]Their review of recent scientific evidence and call for further research to characterize the biological, physical, and chemical interactions between titanium dioxide nanoparticles and bone-forming cells is published in BioResearch Open Access, a peer-reviewed open access journal from Mary Ann Liebert, Inc., publishers. The article is available free on theBioResearch Open Access website.
Jie Yao, Eric Lewallen, PhD, David Lewallen, MD, Andre van Wijnen, PhD, and colleagues from the Mayo Clinic, Rochester, MN and Second Affiliated Hospital of Soochow University, China, coauthored the article entitled “Local Cellular Responses to Titanium Dioxide from Orthopedic Implants The authors examined the results of recently published studies of titanium-based implants, focusing on the direct and indirect effects of titanium dioxide nanoparticles on the viability and behavior of multiple bone-related cell types. They discuss the impact of particle size, aggregation, structure, and the specific extracellular and intracellular (if taken up by the cells) effects of titanium particle exposure.
“The adverse effects of metallic orthopedic particles generated from implants are of significant clinical interest given the large number of procedures carried out each year. This article reviews our current understanding of the clinical issues and highlights areas for future research,” says BioResearch Open Access Editor Jane Taylor, PhD, MRC Centre for Regenerative Medicine, University of Edinburgh, Scotland.
Before getting to the abstract, here’s a link to and a citation for the paper,
Local Cellular Responses to Titanium Dioxide from Orthopedic Implants by Yao, Jie J.; Lewallen, Eric A.; Trousdale, William H.; Xu, Wei; Thaler, Roman; Salib, Christopher G.; Reina, Nicolas; Abdel, Matthew P.; Lewallen, David G.; and van Wijnenm, Andre J.. BioResearch Open Access. July 2017, 6(1): 94-103. https://doi.org/10.1089/biores.2017.0017 Published July 1, 2017
English: Tattoo of Hand of Fatima,. Model: Casini. Date: 4 July 2017, 18:13:41. Source : Own work. Author: Stephencdickson.
For those who like their news in video format, there’s this Canadian Broadcasting Corporation (CBC) news item broadcast on Sep. 11, 2017 (after the commercials),
For those who like text and more detail, scientists at the European Synchrotron Radiation Facility (ESRF) have produced a study of the (at the nanoparticle scale) inks in tattoos. From a Sept. 12, 2017 news item on phys.org,
The elements that make up the ink in tattoos travel inside the body in micro and nanoparticle forms and reach the lymph nodes, according to a study published in Scientific Reports on 12 September  by scientists from Germany and the ESRF, the European Synchrotron, Grenoble (France). It is the first time researchers have found analytical evidence of the transport of organic and inorganic pigments and toxic element impurities as well as in depth characterization of the pigments ex vivo in tattooed tissues. Two ESRF beamlines were crucial in this breakthrough.
The reality is that little is known about the potential impurities in the colour mixture applied to the skin. Most tattoo inks contain organic pigments, but also include preservatives and contaminants like nickel, chromium, manganese or cobalt. Besides carbon black, the second most common ingredient used in tattoo inks is titanium dioxide (TiO2), a white pigment usually applied to create certain shades when mixed with colorants. Delayed healing, along with skin elevation and itching, are often associated with white tattoos, and by consequence with the use of TiO2. TiO2 is also commonly used in food additives, sun screens and paints. Scientists from the ESRF, the German Federal Institute for Risk Assessment, Ludwig-Maximilians University, and the Physikalisch-Technische Bundesanstalt have managed to get a very clear picture on the location of titanium dioxide once it gets in the tissue. This work was done on the ESRF beamlines ID21 and ID16B.
Translocation of tattoo particles from skin to lymph nodes. Upon injection of tattoo inks, particles can be either passively transported via blood and lymph fluids or phagocytized by immune cells and subsequently deposited in regional lymph nodes. After healing, particles are present in the dermis and in the sinusoids of the draining lymph nodes. Credits: C. Seim.
The hazards that potentially derive from tattoos were, until now, only investigated by chemical analysis of the inks and their degradation products in vitro. “We already knew that pigments from tattoos would travel to the lymph nodes because of visual evidence: the lymph nodes become tinted with the colour of the tattoo. It is the response of the body to clean the site of entrance of the tattoo. What we didn’t know is that they do it in a nano form, which implies that they may not have the same behaviour as the particles at a micro level. And that is the problem: we don’t know how nanoparticles react”, explains Bernhard Hesse, one of the two first authors of the study (together with Ines Schreiver, from the German Federal Institute for Risk Assessment) and ESRF visiting scientist.
Particle mapping and size distribution of different tattoo pigment elements. a, d) Ti and the Br containing pigment phthalocyanine green 36 are located next to each other. b, e) Log scale mappings of Ti, Br and Fe in the same areas as displayed in a) and d) reveal primary particle sizes of different pigment species. c, f) Magnifications of the indicated areas in b) and e), respectively. Credits: C. Seim.
X-ray fluorescence measurements on ID21 allowed the team to locate titanium dioxide at the micro and nano range in the skin and the lymphatic environment. They found a broad range of particles with up to several micrometres in size in human skin, but only smaller (nano) particles transported to the lymph nodes. This can lead to the chronic enlargement of the lymph nodes and lifelong exposure. Scientists also used the technique of Fourier transform infrared spectroscopy to assess biomolecular changes in the tissues in the proximity of the tattoo particles.
Ines Schreiver doing experiments on ID16B with Julie Villanova. Credits: B. Hesse.
Altogether the scientists report strong evidence for both migration and long-term deposition of toxic elements and tattoo pigments as well as for conformational alterations of biomolecules that are sometimes linked to cutaneous adversities upon tattooing.
Then next step for the team is to inspect further samples of patients with adverse effects in their tattoos in order to find links with chemical and structural properties of the pigments used to create these tattoos.
An Aug. 28, 2017 news item on Nanotechnology Now features news about nanoparticles and the environment in São Paulo, Brazil,
When ethanol prices at the pump rise for whatever reason, it becomes economically advantageous for drivers of dual-fuel vehicles to fill up with gasoline. However, the health of the entire population pays a high price: substitution of gasoline for ethanol leads to a 30% increase in the atmospheric concentration of ultrafine particulate matter, which consists of particles with a diameter of less than 50 nanometers (nm).
“These polluting nanoparticles are so tiny that they behave like gas molecules. When inhaled, they can penetrate the respiratory system’s defensive barriers and reach the pulmonary alveoli, so that potentially toxic substances enter the bloodstream and may increase the incidence of respiratory and cardiovascular problems,” said Paulo Artaxo, Full Professor at the University of São Paulo’s Physics Institute (IF-USP) and a co-author of the study.
Levels of ultrafine particulate matter in the atmosphere are neither monitored nor regulated by environmental agencies not only in Brazil but practically anywhere in the world, according to Artaxo. The São Paulo State Environmental Corporation (CETESB), for example, routinely monitors only solid particles with diameters of 10,000 nm (PM10) and 2,500 nm (PM2.5) – as well as other gaseous pollutants such as ozone (O3), carbon monoxide (CO) and nitrogen dioxide (NO2).
“Between 75% and 80% of the mass of the nanoparticles we measured in this study corresponds to organic compounds emitted by motor vehicles – carbon in different chemical forms. What these compounds are exactly and how they affect health are questions that require further research,” Artaxo said.
He added that a consensus is forming in the United States and Europe based on recent research indicating that these emissions are a potential health hazard and should be regulated. Several US states, such as California, have laws requiring a 20%-30% ethanol blend in gasoline, which also helps reduce emissions of ultrafine particulate matter.
The data analyzed in the study were collected during the period of January-May 2011, when ethanol prices fluctuated sharply compared with gasoline prices, owing to macroeconomic factors such as variations in the international price of sugar (Brazilian ethanol is made from sugarcane).
Collection was performed at the top of a ten-story building belonging to IF-USP in the western part of São Paulo City. According to Artaxo, the site was chosen because it is relatively distant from the main traffic thoroughfares so that the aerosols there are “older” in the sense that they have already interacted with other substances present in the atmosphere.
“Generally speaking, the pollution we inhale every day at home or at work isn’t what comes out of vehicular exhaust pipes but particles already processed in the atmosphere,” he explained. “For this reason, we chose a site that isn’t directly impacted by primary vehicle emissions.”
The study was conducted during Joel Ferreira de Brito’s postdoctoral research, which Artaxo supervised. The model used to analyze the data was developed by Brazilian economist Alberto Salvo, a professor at the National University of Singapore and first author of the article. Franz Geiger, a chemist at Northwestern University in the US, also collaborated.
“We adapted a sophisticated statistical model originally developed for economic analysis and used here for the first time to analyze the chemistry of atmospheric nanoparticles,” Artaxo said. “The main strength of this tool is that it can work with a large number of variables, such as the presence or absence of rainfall, wind direction, traffic intensity, and levels of ozone, carbon monoxide and other pollutants.”
Analyses were performed before, during and after a sharp fluctuation in ethanol prices leading consumers to switch motor fuels in São Paulo City. While no significant changes were detected in levels of inhalable fine particulate matter (PM2.5 and PM10), the study proved in a real, day-to-day situation that choosing ethanol reduces emissions of ultrafine particles. To date, this phenomenon had only been observed in the laboratory.
“These results reinforce the need for public policies to encourage the use of biofuels, as they clearly show that the public lose in health what they save at the pump when opting for gasoline,” Artaxo said.
In São Paulo, a city with 7 million motor vehicles and the largest urban fleet of flexible-fuel cars, it would be feasible to run all buses on biofuel. “We have the technology for this in Brazil – and at a competitive price,” he said.
The fact that the city’s bus fleet still depends on diesel, Artaxo warned, creates an even worse health hazard in the shape of emissions of black carbon, one of the main components of soot and a pollutant that contributes to global warming. Alongside electricity generation, the transportation sector is the largest emitter of pollutants produced by the burning of fossil fuels.
For Artaxo, incentives for electric, hybrid or biofuel vehicles are vital to reduce greenhouse gas emissions. “By incentivizing biofuels, we could solve several problems at once,” he said. “We could combat climate change, reduce harm to health and foster advances in automotive technology by offering a stimulus for auto makers to develop more economical and efficient cars fueled by ethanol.”
What is in the air we breathe? In addition to the gases we learned about in school there are particles, not just the dust particles you can see, but micro- and nanoparticles too and scientists would like to know more about them.
They may be tiny and invisible, says Xiaoji Xu, but the aerosol particles suspended in gases play a role in cloud formation and environmental pollution and can be detrimental to human health.
Aerosol particles, which are found in haze, dust and vehicle exhaust, measure in the microns. One micron is one-millionth of a meter; a thin human hair is about 30 microns thick.
The particles, says Xu, are among the many materials whose chemical and mechanical properties cannot be fully measured until scientists develop a better method of studying materials at the microscale as well as the much smaller nanoscale (1 nm is one-billionth of a meter).
Xu, an assistant professor of chemistry, has developed such a method and utilized it to perform noninvasive chemical imaging of a variety of materials, as well as mechanical mapping with a spatial resolution of 10 nanometers.
The technique, called peak force infrared (PFIR) microscopy, combines spectroscopy and scanning probe microscopy. In addition to shedding light on aerosol particles, Xu says, PFIR will help scientists study micro- and nanoscale phenomena in a variety of inhomogeneous materials.
The lower portion of this image by Xiaoji Xu’s group shows the operational scheme of peak force infrared (PFIR) microscopy. The upper portion shows the topography of nanoscale PS-b-PMMA polymer islands on a gold substrate. (Image courtesy of Xiaoji Xu)
“Materials in nature are rarely homogeneous,” says Xu. “Functional polymer materials often consist of nanoscale domains that have specific tasks. Cellular membranes are embedded with proteins that are nanometers in size. Nanoscale defects of materials exist that affect their mechanical and chemical properties.
“PFIR microscopy represents a fundamental breakthrough that will enable multiple innovations in areas ranging from the study of aerosol particles to the investigation of heterogeneous and biological materials,” says Xu.
Xu and his group recently reported their results in an article titled “Nanoscale simultaneous chemical and mechanical imaging via peak force infrared microscopy.” The article was published in Science Advances, a journal of the American Association for the Advancement of Science, which also publishes Science magazine.
The article’s lead author is Le Wang, a Ph.D. student at Lehigh. Coauthors include Xu and Lehigh Ph.D. students Haomin Wang and Devon S. Jakob, as well as Martin Wagner of Bruker Nano in Santa Barbara, Calif., and Yong Yan of the New Jersey Institute of Technology.
“PFIR microscopy enables reliable chemical imaging, the collection of broadband spectra, and simultaneous mechanical mapping in one simple setup with a spatial resolution of ~10 nm,” the group wrote.
“We have investigated three types of representative materials, namely, soft polymers, perovskite crystals and boron nitride nanotubes, all of which provide a strong PFIR resonance for unambiguous nanochemical identification. Many other materials should be suited as well for the multimodal characterization that PFIR microscopy has to offer.
“In summary, PFIR microscopy will provide a powerful analytical tool for explorations at the nanoscale across wide disciplines.”
Xu and Le Wang also published a recent article about the use of PFIR to study aerosols. Titled “Nanoscale spectroscopic and mechanical characterization of individual aerosol particles using peak force infrared microscopy,” the article appeared in an “Emerging Investigators” issue of Chemical Communications, a journal of the Royal Society of Chemistry. Xu was featured as one of the emerging investigators in the issue. The article was coauthored with researchers from the University of Macau and the City University of Hong Kong, both in China.
PFIR simultaneously obtains chemical and mechanical information, says Xu. It enables researchers to analyze a material at various places, and to determine its chemical compositions and mechanical properties at each of these places, at the nanoscale.
“A material is not often homogeneous,” says Xu. “Its mechanical properties can vary from one region to another. Biological systems such as cell walls are inhomogeneous, and so are materials with defects. The features of a cell wall measure about 100 nanometers in size, placing them well within range of PFIR and its capabilities.”
PFIR has several advantages over scanning near-field optical microscopy (SNOM), the current method of measuring material properties, says Xu. First, PFIR obtains a fuller infrared spectrum and a sharper image—6-nm spatial resolution—of a wider variety of materials than does SNOM. SNOM works well with inorganic materials, but does not obtain as strong an infrared signal as the Lehigh technique does from softer materials such as polymers or biological materials.
“Our technique is more robust,” says Xu. “It works better with soft materials, chemical as well as biological.”
The second advantage of PFIR is that it can perform what Xu calls point spectroscopy.
“If there is something of interest chemically on a surface,” Xu says, “I put an AFM [atomic force microscopy] probe to that location to measure the peak-force infrared response.
“It is very difficult to obtain these spectra with current scattering-type scanning near-field optical microscopy. It can be done, but it requires very expensive light sources. Our method uses a narrow-band infrared laser and costs about $100,000. The existing method uses a broadband light source and costs about $300,000.”
A third advantage, says Xu, is that PFIR obtains a mechanical as well as a chemical response from a material.
“No other spectroscopy method can do this,” says Xu. “Is a material rigid or soft? Is it inhomogeneous—is it soft in one area and rigid in another? How does the composition vary from the soft to the rigid areas? A material can be relatively rigid and have one type of chemical composition in one area, and be relatively soft with another type of composition in another area.
“Our method simultaneously obtains chemical and mechanical information. It will be useful for analyzing a material at various places and determining its compositions and mechanical properties at each of these places, at the nanoscale.”
A fourth advantage of PFIR is its size, says Xu.
“We use a table-top laser to get infrared spectra. Ours is a very compact light source, as opposed to the much larger sizes of competing light sources. Our laser is responsible for gathering information concerning chemical composition. We get mechanical information from the AFM [atomic force microscope]. We integrate the two types of measurements into one device to simultaneously obtain two channels of information.”
Although PFIR does not work with liquid samples, says Xu, it can measure the properties of dried biological samples, including cell walls and protein aggregates, achieving a 10-nm spatial resolution without staining or genetic modification.
This looks like very exciting work.
Here are links and citations for both studies mentioned in the news release (the most recently published being cited first),
It turns out that Canada has the fifth largest reserve of coal in the world, according to the Coal in Canada Wikipedia entry (Note: Links have been removed),
Coal reserves in Canada rank fifth largest in the world (following the former Soviet Union, the United States, the People’s Republic of China and Australia) at approximately 10 billion tons, 10% of the world total. This represents more energy than all of the oil and gas in the country combined. The coal industry generates CDN$5 billion annually. Most of Canada’s coal mining occurs in the West of the country. British Columbia operates 10 coal mines, Alberta 9, Saskatchewan 3 and New Brunswick one. Nova Scotia operates several small-scale mines, Westray having closed following the 1992 disaster there.
Environmental scientists led by the Virginia Tech College of Science have discovered that the burning of coal produces incredibly small particles of a highly unusual form of titanium oxide.
When inhaled, these nanoparticles can enter the lungs and potentially the bloodstream.
The particulates — known as titanium suboxide nanoparticles — are unintentionally produced as coal is burned, creating these tiniest of particles, as small as 100 millionths of a meter [emphasis mine], said the Virginia Tech-led team. When the particles are introduced into the air — unless captured by high-tech particle traps — they can float away from power plant stacks and travel on air currents locally, regionally, and even globally.
As an example of this, these nanoparticles were found on city streets, sidewalks, and in standing water in Shanghai, China.
The findings are published in the latest issue of Nature Communications under team leader Michael F. Hochella Jr., University Distinguished Professor of Geosciences with the College of Science, and Yi Yang, a professor at East China Normal University in Shanghai. Other study participants include Duke University, the University of Kentucky, and Laurentian University in Canada.
“The problem with these nanoparticles is that there is no easy or practical way to prevent their formation during coal burning,” Hochella said, adding that in nations with strong environmental regulations, such as the United States, most of the nanoparticles would be caught by particle traps. Not so in Africa [a continent not a nation], China, or India, where regulations are lax or nonexistent, with coal ash and smoke entering the open air.
“Due to advanced technology used at U.S.-based coal burning power plants, mandated by the Clean Air Act and the Environmental Protection Agency, most of these nanoparticles and other tiny particles are removed before the final emission of the plant’s exhaust gases,” Hochella said. “But in countries where the particles from the coal burning are not nearly so efficiently removed, or removed at all, these titanium suboxide nanoparticles and many other particle types are emitted into the atmosphere, in part resulting in hazy skies that plague many countries, especially in China and India.”
Hochella and his team found these previously unknown nanoparticles not only in coal ash from around the world and in the gaseous waste emissions of coal plants, but on city streets, in soils and storm water ponds, and at wastewater treatment plants.
“I could not believe what I have found at the beginning, because they had been reported so extremely rarely in the natural environment,” said Yang, who once worked as a visiting professor in Virginia Tech’s Department of Geosciences with Hochella. “It took me several months to confirm their occurrence in coal ash samples.”
The newly found titanium suboxide — called Magnéli phases — was once thought rare, found only sparingly on Earth in some meteorites, from a small area of rock formations in western Greenland, and occasionally in moon rocks. The findings by Hochella and his team indicate that these nanoparticles are in fact widespread globally. They are only now being studied for the first time in natural environments using powerful electron microscopes.
Why did the discovery occur now? According to the report, nearly all coal contains traces of the minerals rutile and/or anatase, both “normal,” naturally occurring, and relatively inert titanium oxides, especially in the absence of light. When those minerals are burned in the presence of coal, research found they easily and quickly converted to these unusual titanium suboxide nanoparticles. The nanoparticles then become entrained in the gases that leave the power plant.
When inhaled, the nanoparticles enter deep into the lungs, potentially all the way into the air sacs that move oxygen into our bloodstream during the normal breathing process. While human lung toxicity of these particles is not yet known, a preliminary biotoxicity test by Hochella and Richard Di Giulio, professor of environmental toxicology, and Jessica Brandt, a doctoral candidate, both at Duke University, indicates that the particles do indeed have toxicity potential.
According to the team, further study is clearly needed, especially biotoxicity testing directly relevant to the human lung. Partnering with coal-power plants either in the United States or China would be ideal, said Yang.
More troubling, the study shows that titanium suboxide nanoparticles are biologically active in the dark, making the particles highly suspect. Exact human health effects are yet unknown.
“Future studies will need to very carefully investigate and access the toxicity of titanium suboxide nanoparticles in the human lung, and this could take years, a sobering thought considering its potential danger,” Hochella said.
As the titanium suboxide nanoparticle itself is produced incidentally, Hochella and his team came across the nanoparticle by accident while studying a 2014 coal ash spill in the Dan River, North Carolina. During the study of the downstream movement of toxic metals in the ash in the Dan River, the team discovered and recognized the presence of small amounts of the highly unusual titanium suboxide.
The group later produced the titanium suboxide nanoparticles when burning coal in a lab simulation.
This new potential air pollution health hazard builds on already established findings from the World Health Organization. It estimates that 3.3 million premature deaths occur worldwide per year due to polluted air, Hochella said. In China, 1.6 million premature deaths are estimated annually due to cardiovascular and respiratory injury from air pollution. Most Chinese megacities top 100 severely hazy days each year with particle concentrations two to four times higher than WHO guidelines, Yang said.
Direct health effects on humans is only one factor. Findings of thousands of scientists have determined that the biggest driver of warming of the planet and the resulting climate change is industrial-scale coal burning. The impact of titanium suboxide nanoparticles found in the atmosphere, in addition to greenhouse gases, on animals, water, and plants is not yet known.
They’ve used an unusual unit of measurement, “100 millionths of a meter,” nanoparticles are usually described in nanometers.
This put me in mind of the famous London smog, which one doesn’t hear about much anymore. For anyone not familiar with that phenomenon, here’s more from the Great Smog of London Wikipedia entry (Note: Links have been removed),
The Great Smog of London, or Great Smog of 1952 sometimes called the Big Smoke, was a severe air-pollution event [emphasis mine] that affected the British capital of London in December 1952. A period of cold weather, combined with an anticyclone and windless conditions, collected airborne pollutants – mostly arising from the use of coal [emphasis mine]– to form a thick layer of smog over the city. It lasted from Friday, 5 December to Tuesday, 9 December 1952 and then dispersed quickly when the weather changed.
It caused major disruption by reducing visibility and even penetrating indoor areas, far more severe than previous smog events experienced in the past, called “pea-soupers”. Government medical reports in the following weeks, however, estimated that up until 8 December, 4,000 people had died as a direct result of the smog and 100,000 more were made ill by the smog’s effects on the human respiratory tract. More recent research suggests that the total number of fatalities was considerably greater, about 12,000.
London had suffered since the 1200s from poor air quality, which worsened in the 1600s, but the Great Smog is known to be the worst air-pollution event in the history of the United Kingdom, and the most significant in terms of its effect on environmental research, government regulation, and public awareness of the relationship between air quality and health. It led to several changes in practices and regulations, including the Clean Air Act 1956. …
Testo, Inc., the world’s leading manufacturer of test and measurement instruments, announces the DiSCmini, the smallest handheld instrument for the measurement of nanoparticle. DiSCmini measures: particle number, average particle diameter and lung-deposited surface area (LDSA) with time resolution and logging at 1 second (1 Hz).
Negative health effects due to nanoparticles appear to correlate particularly well with number concentration or surface. Epidemiological and toxicological studies are still mainly based on total mass, or they use fuzzy proxies like “distance from a busy road” to describe personal exposure, although the health-related effects of particle number concentration are well known. We believe that this contradictory situation is due to the lack of adequate sensors on the market.
This gap is now closed with Testo Particle´s handheld version of the “Diffusion Size Classifier”, testo DiSCmini. The testo DiSCmini is a portable sensor for the measurement of particle number and average diameter with a time resolution of up to 1 second (1 Hz). The simultaneous capture of number concentration and particle size allows the specification of other characteristic parameters, such as the particles surface (Lung Deposited Surface Area, LDSA). The instrument is battery powered with a lifetime of up to 8 hours; data can be recorded on a memory card, and transferred to a external computer via USB cable.
The testo DiSCmini is particularly efficient for personal exposure monitoring in particle-loaded work space with toxic air contaminants such as diesel soot, welding fumes, or industrial nanomaterials.
The testo DiSCmini is based on the electrical charging of the aerosols. Positive air ions generated in a corona discharge are mixed with the aerosol. The charged particles are then detected in two stages by electrometers. The first detector stage is a pile of steel grids; small particles will preferably deposit on it by diffusion. The second stage is a high-efficiency particle filter which captures all the other particles. The mean particle size can be obtained by analysis of the two currents measured on the stages. The particle count is determined with the total current. The testo DiSCmini detects particles ranging in size from 10 to about 700 nm, while the modal value should lie below 300 nm. The concentration range is from about 1’000 to over 1’000’000 particles per cubic centimetre. The accuracy of the measurement depends on the shape of the particle size distribution and number concentration, and is usually around 15-20% compared to a reference CPC. The unit should be serviced and calibrated once a year.
Unlike other instruments the testo DiSCmini needs neither working liquid of any kind nor radioactive sources. Therefore, it can be operated in any position and over extended periods without requiring a liquid refill. Typical applications include the determination of personal exposure in particle-loaded jobs (diesel soot, welding fumes, industrial nanomaterials) or in vulnerable groups (asthmatics, COPD patients). The development of large area survey grids of ambient air is becoming possible. The small size of the testo DiSCmini makes the instrument particularly suitable for personal carry-on measurement campaigns. The high measurement frequency of 1 Hz allows the instrument to monitor rapid changes in the aerosol. This feature is particularly interesting to local or defined sources of particle generation. The equipment is designed for situations and applications where quick and easy access to particle number concentration and average diameter is desired.
The nanotech industry is booming. Every year, several thousands of tonnes of man-made nanoparticles are produced worldwide; sooner or later, a certain part of them will end up in bodies of water or soil. But even experts find it difficult to say exactly what happens to them there. It is a complex question, not only because there are many different types of man-made (engineered) nanoparticles, but also because the particles behave differently in the environment depending on the prevailing conditions.
Researchers led by Martin Scheringer, Senior Scientist at the Department of Chemistry and Applied Biosciences, wanted to bring some clarity to this issue. They reviewed 270 scientific studies, and the nearly 1,000 laboratory experiments described in them, looking for patterns in the behaviour of engineered nanoparticles. The goal was to make universal predictions about the behaviour of the particles.
However, the researchers found a very mixed picture when they looked at the data. “The situation is more complex than many scientists would previously have predicted,” says Scheringer. “We need to recognise that we can’t draw a uniform picture with the data available to us today.”
Nicole Sani-Kast, a doctoral student in Scheringer’s group and first author of the analysis published in the journal PNAS [Proceedings of the National Academy of Sciences], adds: “Engineered nanoparticles behave very dynamically and are highly reactive. They attach themselves to everything they find: to other nanoparticles in order to form agglomerates, or to other molecules present in the environment.”
To what exactly the particles react, and how quickly, depends on various factors such as the acidity of the water or soil, the concentration of the existing minerals and salts, and above all, the composition of the organic substances dissolved in the water or present in the soil. The fact that the engineered nanoparticles often have a surface coating makes things even more complicated. Depending on the environmental conditions, the particles retain or lose their coating, which in turn influences their reaction behaviour.
To evaluate the results available in the literature, Sani-Kast used a network analysis for the first time in this research field. It is a technique familiar in social research for measuring networks of social relations, and allowed her to show that the data available on engineered nanoparticles is inconsistent, insufficiently diverse and poorly structured.
More method for machine learning
“If more structured, consistent and sufficiently diverse data were available, it may be possible to discover universal patterns using machine learning methods,” says Scheringer, “but we’re not there yet.” Enough structured experimental data must first be available.
“In order for the scientific community to carry out such experiments in a systematic and standardised manner, some kind of coordination is necessary,” adds Sani-Kast, but she is aware that such work is difficult to coordinate. Scientists are generally well known for preferring to explore new methods and conditions rather than routinely performing standardized experiments.
Distinguishing man-made and natural nanoparticles
In addition to the lack of systematic research, there is also a second tangible problem in researching the behaviour of engineered nanoparticles: many engineered nanoparticles consist of chemical compounds that occur naturally in the soil. So far it has been difficult to measure the engineered particles in the environment since it is hard to distinguish them from naturally occurring particles with the same chemical composition.
However, researchers at ETH Zurich’s Department of Chemistry and Applied Biosciences, under the direction of ETH Professor Detlef Günther, have recently established an effective method that makes such a distinction possible in routine investigations. They used a state-of-the-art and highly sensitive mass spectrometry technique (called spICP-TOF mass spectrometry) to determine which chemical elements make up individual nanoparticles in a sample.
In collaboration with scientists from the University of Vienna, the ETH researchers applied the method to soil samples with natural cerium-containing particles, into which they mixed engineered cerium dioxide nanoparticles. Using machine learning methods, which were ideally suited to this particular issue, the researchers were able to identify differences in the chemical fingerprints of the two particle classes. “While artificially produced nanoparticles often consist of a single compound, natural nanoparticles usually still contain a number of additional chemical elements,” explains Alexander Gundlach-Graham, a postdoc in Günther’s group.
The new measuring method is very sensitive: the scientists were able to measure engineered particles in samples with up to one hundred times more natural particles.
The researchers have produced a visualization of their network analysis,
The researchers evaluated the experimental data published in the scientific literature using a network analysis. This analysis reveals which types of nanoparticles (blue) have been studied under which environmental conditions (red). (Visualisations: Thomas Kast)
Here are links and citation for two papers associated with this research,