Tag Archives: toxicology

Fantastic Fungi Futures: a multi-night ArtSci Salon event in late November/early December 2019 in Toronto

In fact, I have two items about fungi and I’m starting with the essay first.

Giving thanks for fungi

These foods are all dependent on microorganisms for their distinctive flavor. Credit: margouillat photo/Shutterstock.com

Antonis Rokas, professor at Venderbilt University (Nashville, Tennessee, US), has written a November 25, 2019 essay for The Conversation (h/t phys.org Nov.26.19) featuring fungi and food, Note: Links have been removed),

I am an evolutionary biologist studying fungi, a group of microbes whose domestication has given us many tasty products. I’ve long been fascinated by two questions: What are the genetic changes that led to their domestication? And how on Earth did our ancestors figure out how to domesticate them?

The hybrids in your lager

As far as domestication is concerned, it is hard to top the honing of brewer’s yeast. The cornerstone of the baking, brewing and wine-making industries, brewer’s yeast has the remarkable ability to turn the sugars of plant fruits and grains into alcohol. How did brewer’s yeast evolve this flexibility?

By discovering new yeast species and sequencing their genomes, scientists know that some yeasts used in brewing are hybrids; that is, they’re descendants of ancient mating unions of individuals from two different yeast species. Hybrids tend to resemble both parental species – think of wholpins (whale-dolphin) or ligers (lion-tiger).

… What is still unknown is whether hybridization is the norm or the exception in the yeasts that humans have used for making fermented beverages for millennia.

To address this question, a team led by graduate student Quinn Langdon at the University of Wisconsin and another team led by postdoctoral fellow Brigida Gallone at the Universities of Ghent and Leuven in Belgium examined the genomes of hundreds of yeasts involved in brewing and wine making. Their bottom line? Hybrids rule.

For example, a quarter of yeasts collected from industrial environments, including beer and wine manufacturers, are hybrids.

The mutants in your cheese

Comparing the genomes of domesticated fungi to their wild relatives helps scientists understand the genetic changes that gave rise to some favorite foods and drinks. But how did our ancestors actually domesticate these wild fungi? None of us was there to witness how it all started. To solve this mystery, scientists are experimenting with wild fungi to see if they can evolve into organisms resembling those that we use to make our food today.

Benjamin Wolfe, a microbiologist at Tufts University, and his team addressed this question by taking wild Penicillium mold and growing the samples for one month in his lab on a substance that included cheese. That may sound like a short period for people, but it is one that spans many generations for fungi.

The wild fungi are very closely related to fungal strains used by the cheese industry in the making of Camembert cheese, but look very different from them. For example, wild strains are green and smell, well, moldy compared to the white and odorless industrial strains.

For Wolfe, the big question was whether he could experimentally recreate, and to what degree, the process of domestication. What did the wild strains look and smell like after a month of growth on cheese? Remarkably, what he and his team found was that, at the end of the experiment, the wild strains looked much more similar to known industrial strains than to their wild ancestor. For example, they were white in color and smelled much less moldy.

… how did the wild strain turn into a domesticated version? Did it mutate? By sequencing the genomes of both the wild ancestors and the domesticated descendants, and measuring the activity of the genes while growing on cheese, Wolfe’s team figured out that these changes did not happen through mutations in the organisms’ genomes. Rather, they most likely occurred through chemical alterations that modify the activity of specific genes but don’t actually change the genetic code. Such so-called epigenetic modifications can occur much faster than mutations.

Fantastic Fungi Futures (FFF) Nov. 29, Dec. 1, and Dec. 4, 2019 events in Toronto, Canada

The ArtSci Salon emailed me a November 23, 2019 announcement about a special series being presented in partnership with the Mycological Society of Toronto (MST) on the topic of fungi,

Fantastic Fungi Futures a discussion, a mini exhibition, a special screening, and a workshop revolving around Fungi and their versatile nature.

NOV 29 [2019], 6:00-8:00 PM Fantastic Fungi Futures (FFF): a roundtable discussion and popup exhibition.

Join us for a roundtable discussion. what are the potentials of fungi? Our guests will share their research, as well as professional and artistic practice dealing with the taxonomy and the toxicology, the health benefits and the potentials for sustainability, as well as the artistic and architectural virtues of fungi and mushrooms. The Exhibition will feature photos and objects created by local and Canadian artists who have been working with mushrooms and fungi.

This discussion is in anticipation of the special screening of Fantastic Fungi at the HotDocs Cinema on Dec 1 [2019] our guests:James Scott,Occupational & Environmental Health, Dalla Lana School of Public Health, UofT; Marshall Tyler, Director of Research, Field Trip, Toronto; Rotem Petranker, PhD student, Social Psychology, York University; Nourin Aman, PhD student, fungal biology and Systematics lab, Punjab University; Sydney Gram, PhD student, Ecology & Evolutionary Biology student researcher (UofT/ROM); [and] Tosca Teran, Interdisciplinary artist.

DEC. 1 [2019], 6:15 pm join us to the screening of Fantastic Fungi, at the HotDocs Cinemaget your tickets herehttps://boxoffice.hotdocs.ca/websales/pages/info.aspx?evtinfo=104145~fff311b7-cdad-4e14-9ae4-a9905e1b9cb0 afterward, some of us will be heading to the Pauper’s Pub, just across from the HotDocs Cinema

DEC. 4 [2019], 7:00-10:00PM Multi-species entanglements:Sculpting with Mycelium, @InterAccess, 950 Dupont St., Unit 1 

This workshop is a continuation of ArtSci Salon’s Fantastic Fungi Futures event and the HotDocs screening of Fantastic Fungi.this workshop is open to public to attend, however, pre-registration is required. $5.00 to form a mycelium bowl to take home.

During this workshop Tosca Teran introduces the amazing potential of Mycelium for collaboration at the intersection of art and science. Participants learn how to transform their kitchens and closets in to safe, mini-Mycelium biolabs and have the option to leave the workshop with a live Mycelium planter/bowl form, as well as a wide array of possibilities of how they might work with this sustainable bio-material. 

Bios

Nourin Aman is a PhD student at fungal biology and Systematics lab at Punjab University, Lahore, Pakistan. She is currently a visiting PhD student at the Mycology lab, Royal Ontario Museum. Her research revolves around comparison between macrofungal biodiversity of some reserve forests of Punjab, Pakistan.Her interest is basically to enlist all possible macrofungi of reserve forests under study and describe new species as well from area as our part of world still has many species to be discovered and named. She will be discussing factors which are affecting the fungal biodiversity in these reserve forests.

Sydney Gram is an Ecology & Evolutionary Biology student researcher (UofT/ROM)

Rotem Petranker- Bsc in psychology from the University of Toronto and a MA in social psychology from York University. Rotem is currently a PhD student in York’s clinical psychology program. His main research interest is affect regulation, and the way it interacts with sustained attention, mind wandering, and creativity. Rotem is a founding member oft the Psychedelic Studies Research Program at the University of Toronto, has published work on microdosing, and presented original research findings on psychedelic research in several conferences. He feels strongly that the principles of Open Science are necessary in order to do good research, and is currently in the process of starting the first lab study of microdosing in Canada.

James Scott– PhD, is a ARMCCM Professor and Head Division of Occupational & Environmental Health, Dalla Lana School of Public Health, University of TorontoUAMH Fungal Biobank: http://www.uamh.caUniversity Profile: http://www.dlsph.utoronto.ca/faculty-profile/scott-james-a/Research Laboratory: http://individual.utoronto.ca/jscottCommercial Laboratory: http://www.sporometrics.com

Marshall Tyler– Director of Research, Field Trip. Marshall is a scientist with a deep interest in psychoactive molecules. His passion lies in guiding research to arrive at a deeper understanding of consciousness with the ultimate goal of enhancing wellbeing. At Field Trip, he is helping to develop a lab in Jamaica to explore the chemical and biological complexities of psychoactive fungi.

Tosca Teran, aka Nanotopia, is an Multi-disciplinary artist. Her work has been featured at SOFA New York, Culture Canada, and The Toronto Design Exchange. Tosca has been awarded artist residencies with The Ayatana Research Program in Ottawa and The Icelandic Visual Artists Association through Sím, Reykjavik Iceland and Nes artist residency in Skagaströnd, Iceland. In 2019 she was one of the first Bio-Artists in residence at the Museum of Contemporary Art Toronto in partnership with the Ontario Science Centre as part of the Alien Agencies Collective. A recipient of the 2019 BigCi Environmental Award at Wollemi National Park within the UNESCO World Heritage site in the Greater Blue Mountains. Tosca started collaborating artistically with Algae, Physarum polycephalum, and Mycelium in 2016, translating biodata from non-human organisms into music.@MothAntler @nanopodstudio www.toscateran.com www.nanotopia.net8 

A trailer has been provided for the movie mentioned in the announcement (from the Fantastic Fungi screening webpage on the Mycological Society of Toronto website),

You can find the ArtSci Salon here and the Mycological Society of Toronto (MST) here.

Artificial intelligence (AI) brings together International Telecommunications Union (ITU) and World Health Organization (WHO) and AI outperforms animal testing

Following on my May 11, 2018 posting about the International Telecommunications Union (ITU) and the 2018 AI for Good Global Summit in mid- May, there’s an announcement. My other bit of AI news concerns animal testing.

Leveraging the power of AI for health

A July 24, 2018 ITU press release (a shorter version was received via email) announces a joint initiative focused on improving health,

Two United Nations specialized agencies are joining forces to expand the use of artificial intelligence (AI) in the health sector to a global scale, and to leverage the power of AI to advance health for all worldwide. The International Telecommunication Union (ITU) and the World Health Organization (WHO) will work together through the newly established ITU Focus Group on AI for Health to develop an international “AI for health” standards framework and to identify use cases of AI in the health sector that can be scaled-up for global impact. The group is open to all interested parties.

“AI could help patients to assess their symptoms, enable medical professionals in underserved areas to focus on critical cases, and save great numbers of lives in emergencies by delivering medical diagnoses to hospitals before patients arrive to be treated,” said ITU Secretary-General Houlin Zhao. “ITU and WHO plan to ensure that such capabilities are available worldwide for the benefit of everyone, everywhere.”

The demand for such a platform was first identified by participants of the second AI for Good Global Summit held in Geneva, 15-17 May 2018. During the summit, AI and the health sector were recognized as a very promising combination, and it was announced that AI-powered technologies such as skin disease recognition and diagnostic applications based on symptom questions could be deployed on six billion smartphones by 2021.

The ITU Focus Group on AI for Health is coordinated through ITU’s Telecommunications Standardization Sector – which works with ITU’s 193 Member States and more than 800 industry and academic members to establish global standards for emerging ICT innovations. It will lead an intensive two-year analysis of international standardization opportunities towards delivery of a benchmarking framework of international standards and recommendations by ITU and WHO for the use of AI in the health sector.

“I believe the subject of AI for health is both important and useful for advancing health for all,” said WHO Director-General Tedros Adhanom Ghebreyesus.

The ITU Focus Group on AI for Health will also engage researchers, engineers, practitioners, entrepreneurs and policy makers to develop guidance documents for national administrations, to steer the creation of policies that ensure the safe, appropriate use of AI in the health sector.

“1.3 billion people have a mobile phone and we can use this technology to provide AI-powered health data analytics to people with limited or no access to medical care. AI can enhance health by improving medical diagnostics and associated health intervention decisions on a global scale,” said Thomas Wiegand, ITU Focus Group on AI for Health Chairman, and Executive Director of the Fraunhofer Heinrich Hertz Institute, as well as professor at TU Berlin.

He added, “The health sector is in many countries among the largest economic sectors or one of the fastest-growing, signalling a particularly timely need for international standardization of the convergence of AI and health.”

Data analytics are certain to form a large part of the ITU focus group’s work. AI systems are proving increasingly adept at interpreting laboratory results and medical imagery and extracting diagnostically relevant information from text or complex sensor streams.

As part of this, the ITU Focus Group for AI for Health will also produce an assessment framework to standardize the evaluation and validation of AI algorithms — including the identification of structured and normalized data to train AI algorithms. It will develop open benchmarks with the aim of these becoming international standards.

The ITU Focus Group for AI for Health will report to the ITU standardization expert group for multimedia, Study Group 16.

I got curious about Study Group 16 (from the Study Group 16 at a glance webpage),

Study Group 16 leads ITU’s standardization work on multimedia coding, systems and applications, including the coordination of related studies across the various ITU-T SGs. It is also the lead study group on ubiquitous and Internet of Things (IoT) applications; telecommunication/ICT accessibility for persons with disabilities; intelligent transport system (ITS) communications; e-health; and Internet Protocol television (IPTV).

Multimedia is at the core of the most recent advances in information and communication technologies (ICTs) – especially when we consider that most innovation today is agnostic of the transport and network layers, focusing rather on the higher OSI model layers.

SG16 is active in all aspects of multimedia standardization, including terminals, architecture, protocols, security, mobility, interworking and quality of service (QoS). It focuses its studies on telepresence and conferencing systems; IPTV; digital signage; speech, audio and visual coding; network signal processing; PSTN modems and interfaces; facsimile terminals; and ICT accessibility.

I wonder which group deals with artificial intelligence and, possibly, robots.

Chemical testing without animals

Thomas Hartung, professor of environmental health and engineering at Johns Hopkins University (US), describes in his July 25, 2018 essay (written for The Conversation) on phys.org the situation where chemical testing is concerned,

Most consumers would be dismayed with how little we know about the majority of chemicals. Only 3 percent of industrial chemicals – mostly drugs and pesticides – are comprehensively tested. Most of the 80,000 to 140,000 chemicals in consumer products have not been tested at all or just examined superficially to see what harm they may do locally, at the site of contact and at extremely high doses.

I am a physician and former head of the European Center for the Validation of Alternative Methods of the European Commission (2002-2008), and I am dedicated to finding faster, cheaper and more accurate methods of testing the safety of chemicals. To that end, I now lead a new program at Johns Hopkins University to revamp the safety sciences.

As part of this effort, we have now developed a computer method of testing chemicals that could save more than a US$1 billion annually and more than 2 million animals. Especially in times where the government is rolling back regulations on the chemical industry, new methods to identify dangerous substances are critical for human and environmental health.

Having written on the topic of alternatives to animal testing on a number of occasions (my December 26, 2014 posting provides an overview of sorts), I was particularly interested to see this in Hartung’s July 25, 2018 essay on The Conversation (Note: Links have been removed),

Following the vision of Toxicology for the 21st Century, a movement led by U.S. agencies to revamp safety testing, important work was carried out by my Ph.D. student Tom Luechtefeld at the Johns Hopkins Center for Alternatives to Animal Testing. Teaming up with Underwriters Laboratories, we have now leveraged an expanded database and machine learning to predict toxic properties. As we report in the journal Toxicological Sciences, we developed a novel algorithm and database for analyzing chemicals and determining their toxicity – what we call read-across structure activity relationship, RASAR.

This graphic reveals a small part of the chemical universe. Each dot represents a different chemical. Chemicals that are close together have similar structures and often properties. Thomas Hartung, CC BY-SA

To do this, we first created an enormous database with 10 million chemical structures by adding more public databases filled with chemical data, which, if you crunch the numbers, represent 50 trillion pairs of chemicals. A supercomputer then created a map of the chemical universe, in which chemicals are positioned close together if they share many structures in common and far where they don’t. Most of the time, any molecule close to a toxic molecule is also dangerous. Even more likely if many toxic substances are close, harmless substances are far. Any substance can now be analyzed by placing it into this map.

If this sounds simple, it’s not. It requires half a billion mathematical calculations per chemical to see where it fits. The chemical neighborhood focuses on 74 characteristics which are used to predict the properties of a substance. Using the properties of the neighboring chemicals, we can predict whether an untested chemical is hazardous. For example, for predicting whether a chemical will cause eye irritation, our computer program not only uses information from similar chemicals, which were tested on rabbit eyes, but also information for skin irritation. This is because what typically irritates the skin also harms the eye.

How well does the computer identify toxic chemicals?

This method will be used for new untested substances. However, if you do this for chemicals for which you actually have data, and compare prediction with reality, you can test how well this prediction works. We did this for 48,000 chemicals that were well characterized for at least one aspect of toxicity, and we found the toxic substances in 89 percent of cases.

This is clearly more accurate that the corresponding animal tests which only yield the correct answer 70 percent of the time. The RASAR shall now be formally validated by an interagency committee of 16 U.S. agencies, including the EPA [Environmental Protection Agency] and FDA [Food and Drug Administration], that will challenge our computer program with chemicals for which the outcome is unknown. This is a prerequisite for acceptance and use in many countries and industries.

The potential is enormous: The RASAR approach is in essence based on chemical data that was registered for the 2010 and 2013 REACH [Registration, Evaluation, Authorizations and Restriction of Chemicals] deadlines [in Europe]. If our estimates are correct and chemical producers would have not registered chemicals after 2013, and instead used our RASAR program, we would have saved 2.8 million animals and $490 million in testing costs – and received more reliable data. We have to admit that this is a very theoretical calculation, but it shows how valuable this approach could be for other regulatory programs and safety assessments.

In the future, a chemist could check RASAR before even synthesizing their next chemical to check whether the new structure will have problems. Or a product developer can pick alternatives to toxic substances to use in their products. This is a powerful technology, which is only starting to show all its potential.

It’s been my experience that these claims having led a movement (Toxicology for the 21st Century) are often contested with many others competing for the title of ‘leader’ or ‘first’. That said, this RASAR approach seems very exciting, especially in light of the skepticism about limiting and/or making animal testing unnecessary noted in my December 26, 2014 posting.it was from someone I thought knew better.

Here’s a link to and a citation for the paper mentioned in Hartung’s essay,

Machine learning of toxicological big data enables read-across structure activity relationships (RASAR) outperforming animal test reproducibility by Thomas Luechtefeld, Dan Marsh, Craig Rowlands, Thomas Hartung. Toxicological Sciences, kfy152, https://doi.org/10.1093/toxsci/kfy152 Published: 11 July 2018

This paper is open access.

Faster predictive toxicology of nanomaterials

As more nanotechnology-enabled products make their way to the market and concerns rise regarding safety, scientists work to find better ways of assessing and predicting the safety of these materials, from an Aug. 13, 2016 news item on Nanowerk,

UCLA [University of California at Los Angeles] researchers have designed a laboratory test that uses microchip technology to predict how potentially hazardous nanomaterials could be.

According to UCLA professor Huan Meng, certain engineered nanomaterials, such as non-purified carbon nanotubes that are used to strengthen commercial products, could have the potential to injure the lungs if inhaled during the manufacturing process. The new test he helped develop could be used to analyze the extent of the potential hazard.

An Aug. 12, 2016 UCLA news release, which originated the news item, expands on the theme,

The same test could also be used to identify biological biomarkers that can help scientists and doctors detect cancer and infectious diseases. Currently, scientists identify those biomarkers using other tests; one of the most common is called enzyme-linked immunosorbent assay, or ELISA. But the new platform, which is called semiconductor electronic label-free assay, or SELFA, costs less and is faster and more accurate, according to research published in the journal Scientific Reports.

The study was led by Meng, a UCLA assistant adjunct professor of medicine, and Chi On Chui, a UCLA associate professor of electrical engineering and bioengineering.

ELISA has been used by scientists for decades to analyze biological samples — for example, to detect whether epithelial cells in the lungs that have been exposed to nanomaterials are inflamed. But ELISA must be performed in a laboratory setting by skilled technicians, and a single test can cost roughly $700 and take five to seven days to process.

In contrast, SELFA uses microchip technology to analyze samples. The test can take between 30 minutes and two hours and, according to the UCLA researchers, could cost just a few dollars per sample when high-volume production begins.

The SELFA chip contains a T-shaped nanowire that acts as an integrated sensor and amplifier. To analyze a sample, scientists place it on a sensor on the chip. The vertical part of the T-shaped nanowire converts the current from the molecule being analyzed, and the horizontal portion amplifies that signal to distinguish the molecule from others.

The use of the T-shaped nanowires created in Chui’s lab is a new application of a UCLA patented invention that was developed by Chui and his colleagues. The device is the first time that “lab-on-a-chip” analysis has been tested in a scenario that mimics a real-life situation.

The UCLA scientists exposed cultured lung cells to different nanomaterials and then compared their results using SELFA with results in a database of previous studies that used other testing methods.

“By measuring biomarker concentrations in the cell culture, we showed that SELFA was 100 times more sensitive than ELISA,” Meng said. “This means that not only can SELFA analyze much smaller sample sizes, but also that it can minimize false-positive test results.”

Chui said, “The results are significant because SELFA measurement allows us to predict the inflammatory potential of a range of nanomaterials inside cells and validate the prediction with cellular imaging and experiments in animals’ lungs.”

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

Semiconductor Electronic Label-Free Assay for Predictive Toxicology by Yufei Mao, Kyeong-Sik Shin, Xiang Wang, Zhaoxia Ji, Huan Meng, & Chi On Chui. Scientific Reports 6, Article number: 24982 (2016) doi:10.1038/srep24982 Published online: 27 April 2016

This paper is open access.

Two nano workshops precede OpenTox Euro conference

The main conference OpenTox Euro is focused on novel materials and it’s being preceded by two nano workshops. All of of these events will be taking place in Germany in Oct. 2016. From an Aug. 11, 2016 posting by Lynn L. Bergeson on Nanotechnology Now,

The OpenTox Euro Conference, “Integrating Scientific Evidence Supporting Risk Assessment and Safer Design of Novel Substances,” will be held October 26-28, 2016. … The current topics for the Conference include: (1) computational modeling of mechanisms at the nanoscale; (2) translational bioinformatics applied to safety assessment; (3) advances in cheminformatics; (4) interoperability in action; (5) development and application of adverse outcome pathways; (6) open science applications showcase; (7) toxicokinetics and extrapolation; and (8) risk assessment.

On Oct. 24, 2016, two days before OpenTox Euro, the EU-US Nano EHS [Environmental Health and Safety] 2016 workshop will be held in Germany. The theme is: ‘Enabling a Sustainable Harmonised Knowledge Infrastructure supporting Nano Environmental and Health Safety Assessment’ and the objectives are,

The objective of the workshop is to facilitate networking, knowledge sharing and idea development on the requirements and implementation of a sustainable knowledge infrastructure for Nano Environmental and Health Safety Assessment and Communications. The infrastructure should support the needs required by different stakeholders including scientific researchers, industry, regulators, workers and consumers.

The workshop will also identify funding opportunities and financial models within and beyond current international and national programs. Specifically, the workshop will facilitate active discussions but also identify potential partners for future EU-US cooperation on the development of knowledge infrastructure in the NanoEHS field. Advances in the Nano Safety harmonisation process, including developing an ongoing working consensus on data management and ontology, will be discussed:

– Information needs of stakeholders and applications
– Data collection and management in the area of NanoEHS
– Developments in ontologies supporting NanoEHS goals
– Harmonisation efforts between EU and US programs
– Identify practice and infrastructure gaps and possible solutions
– Identify needs and solutions for different stakeholders
– Propose an overarching sustainable solution for the market and society

The presentations will be focused on the current efforts and concrete achievements within EU and US initiatives and their potential elaboration and extension.

The second workshop is being held by the eNanoMapper (ENM) project on Oct. 25, 2016 and concerns Nano Modelling. The objectives and workshop sessions are:

1. Give the opportunity to research groups working on computational nanotoxicology to disseminate their modelling tools based on hands-on examples and exercises
2. Present a collection of modelling tools that can span the entire lifecycle of nanotox research, starting from the design of experiments until use of models for risk assessment in biological and environmental systems.
3. Engage the workshop participants in using different modelling tools and motivate them to contribute and share their knowledge.

Indicative workshop sessions

• Preparation of datasets to be used for modelling and risk assessment
• Ontologies and databases
• Computation of theoretical descriptors
• NanoQSAR Modelling
• Ab-initio modelling
• Mechanistic modelling
• Modelling based on Omics data
• Filling data gaps-Read Across
• Risk assessment
• Experimental design

We would encourage research teams that have developed tools in the areas of computational nanotoxicology and risk assessment to demonstrate their tools in this workshop.

That’s going to be a very full week in Germany.

You can register for OpenTox Euro and more here.

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

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

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

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

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

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

39,000 metric tons of nanoparticles

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

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

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

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

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

Copyright © 2016 American Chemical Society

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

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

Identifying minute amounts of nanomaterial in environmental samples

It’s been a while since I’ve had a story from one of Germany’s Franhaufer Institutes. Their stories are usually focused on research that’s about to commercialized but that’s not the case this time according to an April 28, 2016 news item on Nanowerk,

It is still unclear what the impact is on humans, animals and plants of synthetic nanomaterials released into the environment or used in products. It’s very difficult to detect these nanomaterials in the environment since the concentrations are so low and the particles so small. Now the partners in the NanoUmwelt project have developed a method that is capable of identifying even minute amounts of nanomaterials in environmental samples.

An April 28, 2016 Fraunhofer Institute press release, which originated the news item, provides more detail about the technology and about the NanoUmwelt project along with a touch of whimsy,

Tiny dwarves keep our mattresses clean, repair damage to our teeth, stop eggs sticking to our pans, and extend the shelf life of our food. We are talking about nanomaterials – “nano” comes from the Greek word for “dwarf”. These particles are just a few billionths of a meter small, and they are used in a wide range of consumer products. However, up to now the impact of these materials on the environment has been largely unknown, and information is lacking on the concentrations and forms in which they are present there. “It’s true that many laboratory studies have examined the effect of nanomaterials on human and animal cells. To date, though, it hasn’t been possible to detect very small amounts in environmental samples,” says Dr. Yvonne Kohl from the Fraunhofer Institute for Biomedical Engineering IBMT in Sulzbach.

A millionth of a milligram per liter 

That is precisely the objective of the NanoUmwelt project. The interdisciplinary project team is made up of eco- and human toxicologists, physicists, chemists and biologists, and they have just managed to take their first major step forward in achieving their goal: they have developed a method for testing a variety of environmental samples such as river water, animal tissue, or human urine and blood that can detect nanomaterials at a concentration level of nanogram per liter (ppb – parts per billion). That is equivalent to half a sugar cube in the volume of water contained in 1,000 competition swimming pools. Using the new method, it is now possible to detect not just large amounts of nanomaterials in clear fluids, as was previously the case, but also very few particles in complex substance mixtures such as human blood or soil samples. The approach is based on field-flow fractionation (FFF), which can be used to separate complex heterogeneous mixtures of fluids and particles into their component parts – while simultaneously sorting the key components by size. This is achieved by the combination of a controlled flow of fluid and a physical separation field, which acts perpendicularly on the flowing suspension.

For the detection process to work, environmental samples have to be appropriately processed. The team from Fraunhofer IBMT’s Bioprocessing & Bioanalytics Department prepared river water, human urine, and fish tissue to be fit for the FFF device. “We prepare the samples with special enzymes. In this process, we have to make sure that the nanomaterials are not destroyed or changed. This allows us to detect the real amounts and forms of the nanomaterials in the environment,” explains Kohl. The scientists have special expertise when it comes to providing, processing and storing human tissue samples. Fraunhofer IBMT has been running the “German Environmental Specimen Bank (ESB) – Human Samples”since January 2012 on behalf of Germany’s Environment Agency (UBA). Each year the research institute collects blood and urine samples from 120 volunteers in four cities in Germany. Individual samples are a valuable tool for mapping the trends over time of human exposure to pollutants. ”In addition, blood and urine samples have been donated for the NanoUmwelt project and put into cryostorage at Fraunhofer IBMT. We used these samples to develop our new detection method,” says Dr. Dominik Lermen, manager of the working group on Biomonitoring & Cryobanks at Fraunhofer IBMT. After approval by the UBA, some of the human samples in the ESB archive may also be examined using the new method.

Developing new cell culture models

Nanomaterials end up in the environment via different pathways, inter alia the sewage system. Human beings and animals presumably absorb them through biological barriers such as the lung or intestine. The project team is simulating these processes in petri dishes in order to understand how nanomaterials are transported across these barriers. “It’s a very complex process involving an extremely wide range of cells and layers of tissue,” explains Kohl. The researchers replicate the processes in a way as realistic as possible. They do this by, for instance, measuring the electrical flows within the barriers to determine the functionality of these barriers – or by simulating lung-air interaction using clouds of artificial fog. In the first phase of the NanoUmwelt project, the IBMT team succeeded in developing several cell culture models for the transport of nanomaterials across biological barriers. IBMT worked together with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME, which used pluripotent stem cells to develop a model for investigating cardiotoxicity. Empa, the Swiss partner in the project, delivered a placental barrier model for studying the transport of nanomaterials between mother and child.

Next, the partners want to use their method to measure the concentrations of nanoparticles in a wide variety of environmental samples. They will then analyze the results obtained so as to be in a better position to assess the behavior of nanomaterials in the environment and their potential danger for humans, animals, and the environment. “Our next goal is to detect particles in even smaller quantities,” says Kohl. To achieve this, the scientists are planning to use special filters to remove distracting elements from the environmental samples, and they are looking forward to develop new processing techniques.
NanoUmwelt – the objective

The NanoUmwelt research project was launched in October 2014 and will last for 36 months. Its objective is to develop methods for detecting minute amounts of nanomaterials in environmental samples. Using this information, the project partners will assess the effect of nanomaterials on humans, animals, and the environment. They are focusing on commercially significant, slowly degradable, metallic (silver, titanium dioxide), carbonic (carbon nanotubes) and polymer-based (polystyrene) nanomaterials.

http://www.nanopartikel.info/projekte/laufende-projekte/nanoumwelt

NanoUmwelt – the partners

The German Federal Ministry for Education and Research (BMBF) is providing the NanoUmwelt project with 1.8 million euros of funding as part of its NanoCare program. Led by Postnova Analytics GmbH, ten further partners are collaborating together on the project. Besides the Fraunhofer Institutes for Biomedical Engineering IBMT and for Molecular Biology and Applied Ecology IME, these partners include Germany’s Environment Agency, Empa (the Swiss Federal Laboratories for Materials Science and Technology), PlasmaChem GmbH, Senova GmbH (biological sciences and engineering), fzmb GmbH (Research Centre of Medical Technology and Biotechnology), the universities of Trier and Frankfurt, and the Rhine Water Control Station in Worms.

http://www.nanopartikel.info/projekte/laufende-projekte/nanoumwelt

How small is nano?

A nanometer (nm) is a billionth of a meter. To put this into context: the size of a single nanoparticle relative to a football is the same as that of a football relative to the earth. In the main, nanoscopic particles are not new materials. It’s simply that the increased overall surface area of these tiny particles gives them new functionalities as against larger particles of the same material.


The German Environmental Specimen Bank  

The German Environmental Specimen Bank (ESB) provides the country’s Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) with a scientific basis both for adopting appropriate measures concerning environment and nature conservation and for monitoring the success of those measures. The human samples collected by the Fraunhofer Institute for Biomedical Engineering IBMT on behalf of Germany’s Environment Agency (UBA) give an overview of human exposure to environmental pollutants.

https://www.umweltprobenbank.de/de

Assuming I’ve understood this correctly, the NanoUmwelt project will be ending in 2017 (36 months in total) and the researchers have expended 1/2 of the time (18 months) allotted to developing a technique for measuring nanomaterials of heretofore unheard of quantities in environmental samples. With that done, researchers are now going to use the technique with human samples over the next 18 months.

What is the effect of nanoscale plastic on marine life?

A Nov.27, 2015 news item on Nanowerk announces a new UK (United Kingdom) research project designed to answer the question: what impact could nanoscale plastic particles  have on the marine environment?,

As England brings in pricing on plastic carrier bags, and Scotland reveals that similar changes a little over a year ago have reduced the use of such bags by 80%, new research led by Heriot-Watt University in conjunction with Plymouth University will look at the effect which even the most microscopic plastic particles can have on the marine environment.

While images of large ‘islands’ of plastic rubbish or of large marine animals killed or injured by the effects of such discards have brought home some of the obvious negative effects of plastics in the marine environment, it is known that there is more discarded plastic out there than we can account for, and much of it will have degraded into small or even microscopic particles.

It is the effect of these latter, known as nano-plastics, which will be studied under a £1.1m research project, largely funded by NERC [UK Natural Environment Research Council] and run by Heriot-Watt and Plymouth Universities.

A Nov. 25, 2015 Herriot-Watt University press release, which originated the news item, provides more details,

The project, RealRiskNano, will look at the risks these tiny plastic particles pose to the food web including filter-feeding organisms like mussels, clams and sediment dwelling organisms. It will focus on providing information to improve environmental risk assessment for nanoplastics, based on real-world exposure scenarios replicated in the laboratory.

Team leader Dr Theodore Henry, Associate Professor of Toxicology at Heriot-Watt’s School of Life Sciences, said that the study will build on previous research on nano-material toxicology, but will provide information which the earlier studies did not include.

“Pieces of plastic of all sizes have been found in even the most remote marine environments. It’s relatively easy to see some of the results: turtles killed by easting plastic bags which they take for jelly fish, or large marine mammals drowned when caught in discarded ropes and netting.

“But when plastics fragment into microscopic particles, what then? It’s easy to imagine that they simply disappear, but we know that nano-particles pose their own distinct threats purely because of their size. They’re small enough to be transported throughout the environment with unknown effects on organisms including toxicity and interference with processes of the digestive system.

An important component of the project, to be investigated by Dr Tony Gutierrez at Heriot-Watt, will be the study of interactions between microorganisms and the nanoplastics to reveal how these interactions affect their fate and toxicology.

The aim, said Dr Henry, is to provide the information which is needed to effect real change.“We simply don’t know what effects these nano-plastic particles may pose to the marine environment, to filter-feeders and on to fish, and through the RealRiskNano project we aim to provide this urgently needed information to the people whose job it is to assess risk to the marine ecosystem and decide what steps need to be taken to mitigate it.”

You can find the RealRiskNano website here.

Beginner’s guide to carbon nanotubes and nanowires

There’s a very nice Apr. 11, 2013  introductory article by David L. Chandler for the Massachusetts Institute of Technology (MIT) news office) about carbon and other nanotubes and nanowires,

The initial discovery of carbon nanotubes — tiny tubes of pure carbon, essentially sheets of graphene rolled up unto a cylinder — is generally credited to a paper published in 1991 by the Japanese physicist Sumio Ijima (although some forms of carbon nanotubes had been observed earlier). Almost immediately, there was an explosion of interest in this exotic form of a commonplace material. Nanowires — solid crystalline fibers, rather than hollow tubes — gained similar prominence a few years later.

Due to their extreme slenderness, both nanotubes and nanowires are essentially one-dimensional. “They are quasi-one-dimensional materials,” says MIT associate professor of materials science and engineering Silvija Gradečak: “Two of their dimensions are on the nanometer scale.” This one-dimensionality confers distinctive electrical and optical properties.

For one thing, it means that the electrons and photons within these nanowires experience “quantum confinement effects,” Gradečak says. And yet, unlike other materials that produce such quantum effects, such as quantum dots, nanowires’ length makes it possible for them to connect with other macroscopic devices and the outside world.

The structure of a nanowire is so simple that there’s no room for defects, and electrons pass through unimpeded, Gradečak explains. This sidesteps a major problem with typical crystalline semiconductors, such as those made from a wafer of silicon: There are always defects in those structures, and those defects interfere with the passage of electrons.

H/T Nanowerk Apr. 11, 2013 news item. There’s more to read at the MIT website and I recommend this as a good beginner’s piece since the focus is entirely on what carbon nanotubes and nanowires are , how they are formed, and which distinctive properties are theirs. You can find some of this information in the odd paragraph of a news release touting the latest research but I’m very excited to find this much explanatory material in one place.

Another very good explanatory piece, this one focused on carbon nanotubes and risk, is a video produced by Dr. Andrew Maynard for his Risk Bites series. I featured and embedded it in my Mar. 15, 2013 posting. titled, The long, the short, the straight, and the curved of them: all about carbon nanotubes.  You can also find the video in Andrew’s Mar. 14, 2013 posting on his 2020 Science blog where he also writes about the then recently released information from the US National Institute of Occupational Health and Safety on carbon nanotubes and toxicity.

Looking blue? Maybe it’s silver nanoparticles

Looking blue can mean feeling sad or it can indicate that you have argyria, a condition caused by ingesting too much silver. An Oct. 29, 2012 news item on Nanowerk about research on argyria taking place at Brown University reveals the latest insight on the cause for this condition,

Researchers from Brown University have shown for the first time how ingesting too much silver can cause argyria, a rare condition in which patients’ skin turns a striking shade of grayish blue.

“It’s the first conceptual model giving the whole picture of how one develops this condition,” said Robert Hurt, professor of engineering at Brown and part of the research team. “What’s interesting here is that the particles someone ingests aren’t the particles that ultimately cause the disorder.”

Scientists have known for years argyria had something to do with silver. The condition has been documented in people who (ill advisedly) drink antimicrobial health tonics containing silver nanoparticles and in people who have had extensive medical treatments involving silver. Tissue samples from patients showed silver particles actually lodged deep in the skin, but it wasn’t clear how they got there.

As it turns out, argyria is caused by a complex series of chemical reactions, Hurt said. His paper on the subject, authored with Brown colleagues Jingyu Liu, Zhongying Wang, Frances Liu, and Agnes Kane, is published in the journal ACS Nano (“Chemical Transformations of Nanosilver in Biological Environments” [behind a paywall]).

The Oct. 25, 2012 Brown University news release (which originated the news item) provides more detail,

Hurt and his team have been studying the environmental impact of silver, specifically silver nanoparticles, for years. They’ve found that nanosilver tends to corrode in acidic environments, giving off charged ions — silver salts — that can be toxic in large amounts. Hurt’s graduate student, Jingyu Liu (now a postdoctoral fellow at the National Institute of Standards and Technology), thought those same toxic ions might also be produced when silver enters the body, and could play a role in argyria.

To find out, the researchers mixed a series chemical treatments that could simulate what might happen to silver inside the body. One treatment simulated the acidic environment in the gastrointestinal tract; one mimicked the protein content of the bloodstream; and a collagen gel replicated the base membranes of the skin.

They found that nanosilver corrodes in stomach acid in much the same way it does in other acidic environments. Corrosion strips silver atoms of electrons, forming positively charged silver salt ions. Those ions can easily be taken into the bloodstream through channels that absorb other types of salt. That’s a crucial step, Hurt said. Silver metal particles themselves aren’t terribly likely to make it from the GI tract to the blood, but when they’re transformed into a salt, they’re ushered right through.

From there, Hurt and his team showed that silver ions bind easily with sulfur present in blood proteins, which would give them a free ride through the bloodstream. Some of those ions would eventually end up in the skin, where they’d be exposed to light.

To re-create this end stage, the researchers shined ultraviolet light on collagen gel containing silver ions. The light caused electrons from the surrounding materials to jump onto the unstable ions, returning them to their original state — elemental silver. This final reaction is ultimately what turns patients’ skin blue. The photoreaction is similar to the way silver is used in black and white photography [emphasis mine]. When exposed to light, silver salts on a photographic film reduce to elemental silver and darken, creating an image.

While I find the notion that the body’s reaction to silver is similar to the processing of silver in black and white photography, it’s the discussion about toxicity that most interests me. The scientists at Brown are suggesting that   standard ‘ingestable’ silver could be more dangerous than silver nanoparticles when they are consumed in the body,

This research, however, “would be one piece of evidence that you could treat nanoparticles in the same way as other forms of silver,” Hurt says.

That’s because the bioavailable form of silver — the form that is absorbed into the bloodstream — is the silver salt that’s made in the stomach. Any elemental silver that’s ingested is just the raw material to make that bioavailable salt. So ingesting silver in any form, be it nano or not, would have basically the same effect, Hurt said.

“The concern in this case is the total dose of silver, not what form it’s in,” Hurt said. “This study implies that silver nanoparticles will be less toxic than an equivalent amount of silver salt, at least in this exposure scenario [emphasis mine].”

This research provides more evidence supporting Dr. Andrew Maynard’s contention that creating definitions and regulations for nanomaterials based on size may not be the best approach. Here’s his response to my question (in an Oct. 24, 2011 posting) about the then newly adopted Health Canada definition (which includes size) for nanomaterials,

The problem is that, while the Health Canada is a valiant attempt to craft a definition based on the current state of science, it is still based on a premise – that size within a well defined range is a robust indicator of novel risk – that is questionable [emphasis mine].  Granted, they try to compensate for the limitations of this premise, but the result still smacks of trying to shoehorn the science into an assumption of what is important.

One can only wait as the evidence continues to mount on one side or the other. In the meantime, I don’t one can ever go wrong with BB King, one of the great blues guitar players (Blues Boys Tune),

Nanomaterials and toxicology (US Environmental Protection Agency and National Institute of Occupational Health and Safety)

It seems to be ‘toxicology and nanomaterials’ season right now. In addition to the ISO (International Standards Organization) technical report on nanomaterials and toxicology which was released in early June (mentioned in my June 4, 2012 posting), the US Environmental Protection Agency (EPA) and the US National Institute of Occupational Safety and Health (NIOSH) have released new reports.

Yesterday (July 2, 2012), the EPA posted a notice on the US Federal Register about a report, a commenting period, and a public information exchange meeting for “Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotubes and Decabromodiphenyl Ether Flame-Retardant Coatings Applied to Upholstery Textiles.”

As I noted in an Aug. 27, 2010 posting, the EPA has adopted a very interesting approach to studying possible toxicological effects due to nanomaterials (and other materials),

Such case studies do not represent completed or even preliminary assessments; rather, they are intended as a starting point in a process to identify and prioritize possible research directions to support future assessments of nanomaterials.

Part of the rationale for focusing on a series of nanomaterial case studies is that such materials and applications can have highly varied and complex properties that make considering them in the abstract or in generalities quite difficult. Different materials and different applications of a given material could raise unique questions or issues as well as some issues that are common to various applications of a given nanomaterial or even to different nanomaterials. After several individual case studies have been examined, refining a strategy for nanomaterials research to support long-term assessment efforts should be possible. (p. 19 PDF, p. 1-1 in print version of a  US EPA silver nanomaterials draft report)

The July 3, 2012 news item on Nanowerk offers more detail about this latest case study (Note: I have removed a link),

EPA announces the release of the draft report, Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotube and Decabromodiphenyl Ether Flame-Retardant Coatings Applied to Upholstery Textiles (External Review Draft), for public viewing and comment. This was announced in a July 2, 2012 Federal Register Notice  along with information about the upcoming public Information Exchange Meeting scheduled for October 29, 2012. The purpose of this meeting is to receive comments and questions on the draft document, as well as provide information on the draft document and a workshop process that it will be used in, which is being conducted independently by RTI International, a contractor for EPA. The deadline for comments on the draft document is August 31, 2012. [emphases mine]

The notice on the EPA website offers details and extensive links to satisfy your information needs on this matter,

The draft document is intended to be used as part of a process to identify what is known and, more importantly, what is not yet known that could be of value in assessing the broad implications of specific nanomaterials. Like previous case studies (see History/ Chronology below [on the EPA website]), this draft case study on multiwalled carbon nanotubes (MWCNTs) is based on the comprehensive environmental assessment (CEA) approach, which consists of both a framework and a process. Unlike previous case studies this case study incorporates information about a traditional (i.e., “non-nano-enabled”) product, against which the MWCNT flame-retardant coating applied to upholstery textiles (i.e., the “nano-enabled” product) can be compared. The comparative element serves dual-purposes: 1) to provide a more robust database that facilitates identification of data gaps related to the nano-enabled product and 2) to provide a context for identifying key factors and data gaps for future efforts to evaluate risk-related trade-offs between a nano-enabled and non-nano-enabled product.

This draft case study does not represent a completed or even a preliminary assessment of MWCNTs; rather, it uses the CEA framework to structure information from available literature and other resources (e.g., government reports) on the product life cycle, fate and transport processes in various environmental media, exposure-dose characterization, and impacts in human, ecological, and environmental receptors. Importantly, information on other direct and indirect ramifications of both primary and secondary substances or stressors associated with the nanomaterial is also included when available. The draft case study provides a basis for the next step of the CEA process, whereby collective judgment is used to identify and prioritize research gaps to support future assessment efforts that inform near-term risk management goals.

Meanwhile, NIOSH has released a safety guide (from the June 29, 2012 news item on Nanowerk),

The National Institute for Occupational Safety and Health (NIOSH) has published “General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories” (pdf).

With the publication of this document, NIOSH hopes to raise awareness of the occupational safety and health practices that should be followed during the synthesis, characterization, and experimentation with engineered nanomaterials in a laboratory setting. The document contains recommendations on engineering controls and safe practices for handling engineered nanomaterials in laboratories and some pilot scale operations. This guidance was designed to be used in tandem with well-established practices and the laboratory’s chemical hygiene plan. As our knowledge of nanotechnology increases, so too will our efforts to provide additional guidance materials for working safely with engineered nanomaterials.

Here is more information  from the executive summary of the General Safe Practices for Working with Engineered Nanomaterials in Research Laboratories,

Risk Management

Risk management is an integral part of occupational health and safety. Potential expo­sures to nanomaterials can be controlled in research laboratories through a flexible and adaptive risk management program. An effective program provides the framework to anticipate the emergence of this technology into laboratory settings, recognize the po­tential hazards, evaluate the exposure to the nanomaterial, develop controls to prevent or minimize exposure, and confirm the effectiveness of those controls.

Hazard Identification

Experimental animal studies indicate that potentially adverse health effects may result from exposure to nanomaterials. Experimental studies in rodents and cell cultures have shown that the toxicity of ultrafine particles or nanoparticles is greater than the toxicity of the same mass of larger particles of similar chemical composition.

Research demonstrates that inhalation is a significant route of exposure for nanoma­terials. Evidence from animal studies indicates that inhaled nanoparticles may deposit deep in lung tissue, possibly interfering with lung function. It is also theorized that nanoparticles may enter the bloodstream through the lungs and transfer to other or­gans. Dermal exposure and subsequent penetration of nanomaterials may cause local or systemic effects. Ingestion is a third potential route of exposure. Little is known about the possible adverse effects of ingestion of nanomaterials, although some evidence sug­gests that nanosized particles can be transferred across the intestinal wall.

Exposure Assessment

Exposure assessment is a key element of an effective risk management program. The ex­posure assessment should identify tasks that contribute to nanomaterial exposure and the workers conducting those tasks. An inventory of tasks should be developed that in­cludes information on the duration and frequency of tasks that may result in exposure, along with the quantity of the material being handled, dustiness of the nanomaterial, and its physical form. A thorough understanding of the exposure potential will guide exposure assessment measurements, which will help determine the type of controls re­quired for exposure mitigation.

Exposure Control

Exposure control is the use of a set of tools or strategies for decreasing or eliminating worker exposure to a particular agent. Exposure control consists of a standardized hi­erarchy to include (in priority order): elimination, substitution, isolation, engineering controls, administrative controls, or if no other option is available, personal protective equipment (PPE).

Substitution or elimination is not often feasible for workers performing research with nanomaterials; however, it may be possible to change some aspects of the physical form of the nanomaterial or the process in a way that reduces nanomaterial release.

Isolation includes the physical separation and containment of a process or piece of equipment, either by placing it in an area separate from the worker or by putting it within an enclosure that contains any nanomaterials that might be released.

Engineering controls include any physical change to the process that reduces emissions or exposure to the material being contained or controlled. Ventilation is a form of engi­neering control that can be used to reduce occupational exposures to airborne particu­lates. General exhaust ventilation (GEV), also known as dilution ventilation, permits the release of the contaminant into the workplace air and then dilutes the concentration to an acceptable level. GEV alone is not an appropriate control for engineered nano­materials or any other uncharacterized new chemical entity. Local exhaust ventilation (LEV), such as the standard laboratory chemical hood (formerly known as a laboratory fume hood), captures emissions at the source and thereby removes contaminants from the immediate occupational environment. Using selected forms of LEV properly is ap­propriate for control of engineered nanomaterials.

Administrative controls can limit workers’ exposures through techniques such as us­ing job-rotation schedules that reduce the time an individual is exposed to a substance. Administrative controls may consist of standard operating procedures, general or spe­cialized housekeeping procedures, spill prevention and control, and proper labeling and storage of nanomaterials. Employee training on the appropriate use and handling of nanomaterials is also an important administrative function.

PPE creates a barrier between the worker and nanomaterials in order to reduce expo­sures. PPE may include laboratory coats, impervious clothing, closed-toe shoes, long pants, safety glasses, face shields, impervious gloves, and respirators.

Other Considerations

Control verification or confirmation is essential to ensure that the implemented tools or strategies are performing as specified. Control verification can be performed with traditional industrial hygiene sampling methods, including area sampling, personal sampling, and real-time measurements. Control verification may also be achieved by monitoring the performance parameters of the control device to ensure that design and performance criteria are met.

Other important considerations for effective risk management of nanomaterial expo­sure include fire and explosion control. Some studies indicate that nanomaterials may be more prone to explosion and combustion than an equivalent mass concentration of larger particles.

Occupational health surveillance is used to identify possible injuries and illnesses and is recommended as a key element in an effective risk management program. Basic medical screening is prudent and should be conducted under the oversight of a qualified health-care professional. (pp. 9 – 11 PDF or pp. vii – ix in print)

The guidance as per the executive summary seems to rely heavily on what I imagine are industrial hygiene practices that should be followed whether or not laboratories are researching nanomaterials.