Tech

Well-meaning climate measures can make matters worse

Lifestyle changes can reduce our greenhouse gas emissions and help protect nature. While some actions offer great potential, some aren't as effective as we think and may even require more land and water, such as shifting to renewable energy.

We need to change our lifestyle if we want to make a dent in greenhouse gas emissions in Europe. But not all changes proposed in the name of climate mitigation are for the better, according to research from NTNU and others.

"The most promising solutions involve reducing motorized transport, switching to a more shared economy, saving energy, using fewer household chemicals and plastics, reducing food waste or food surpluses, and increasing the lifetime of clothing and other durable goods. These measures assume that we shift our focus from infinite economic growth to building a more sustainable society and achieving environmental goals," says Gibran Vita, a researcher in NTNU's Industrial Ecology Programme and at the University of Kassel in Germany.

Risky tactics

First, let's take a look at what tactics fall short or could even make matters worse, at least in some areas.

True enough, transitioning to more renewable electricity may lessen our carbon footprint by around 3 per cent, but at the same time land use could increase by more than 3 per cent, which is no doubt apparent to anyone who has been following the debate on wind turbines in Norwegian wilderness areas. These factors need to be weighed against one another.

The spring UN report by Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) pointed out that changes in land and sea use pose the greatest threat to the world's species, more than direct exploitation of organisms, with climate change in third place.

Increasing the use of renewable fuels is another risky tactic. Despite its potential to reduce carbon emissions by up to 12 per cent, such a measure would also increase land use and water consumption by 5-6 per cent. This should likely be considered in the debate on electric and hydrogen cars.

To exhaustively repair and renovate the existing building stock might help energy efficiency but also, perhaps somewhat surprisingly, increase land use by over 10 per cent. The materials have to come from somewhere.

If we want to reduce the impact of Europeans on the environment, then we need to know what we're doing.

Rich countries: going for growth or enough?

Specialists in consumption and how different choices affect emissions of greenhouse gases, land use, water consumption and toxicity were part of a research group that analysed two different main directions, with several sub-scenarios, that the world can take.

Green Consumption or Less Consumption? Varying creeds exist even among people who know the climate crisis is real and human caused. These include:

* Green growth: Some people believe it's possible to achieve "green growth". They tend to think that it is enough to consume products that pollute less and to adopt more environmentally friendly technologies like renewable energy, while at the same time producing renewable materials. Green growth also includes moving to a circular economy where we minimize raw material use, energy consumption, and emissions - and throw away as little as possible.

* Enough is enough: Other people think we need to take more drastic steps and believe that those of us in the richest parts of the world have to learn to live with just enough to maintain the standard of living we have today instead of pursuing continued growth. This option means that people work less and have more time, but also that we protect the quality of life with strong welfare systems.

300 proposals analysed

About 200 people with backgrounds in business, academia, agencies and other sectors came together to hammer out proposals for reducing greenhouse gas emissions. The working groups generated more than 300 visions for change.

Gibran Vita and his group in turn divided the proposals into 36 different scenarios, 17 of them for green growth, and 19 of sufficiency, assuming consumption is limited to a reasonable level in the richest parts of the world.

"Although the scenarios that assume no increased consumption would be the most effective, the measures proposed in them are less popular than green consumption, since they're at odds with today's view that consumption equates to quality of life," says Vita.

The impacts of the various measures naturally vary greatly.

Food, transportation and reuse

"We found that switching to plant-based foods, less motorized transport and energy-efficient houses can reduce climate impact in Europe by 10 per cent or more," says Vita.

A large scale switch to plant-based foods can reduce your carbon footprint by up to 15 per cent. Throwing away less food could yield an additional 5 per cent reduction in carbon and up to 16 per cent less water.

A massive transition to cycling and walking could by itself offset European greenhouse gas emissions by up to 26 per cent and reduce the pressure on land and water resources by up to 4 per cent.

"But if you walk or bike daily and then reward yourself with a plane flight, you could still end up with a bigger footprint than today," Vita says.

Repairing and buying less household electronics could reduce emissions and consumption by up to 6 per cent.

Repairing and re-using clothing would reduce consumption more than 2 per cent. But switching to plant-based textiles would amount to very little, if anything. Only lowering fashion consumption makes a significant difference.

People can share more

The effects of switching to a more local economy, where numerous tasks are taken care of cooperatively in the local area, vary greatly depending on how this is done. The impact can therefore range from a 3 to 23 per cent reduction in a community's climate footprint.

If we build fewer homes because more people choose to live together, or we divide existing units into smaller ones, Europe's carbon footprint could shrink by about 1.8 per cent, and the pressure on rural areas by about 3.5 per cent. Using natural building materials probably has no significant effect.

Vita notes that some of the measures may have effects in other parts of the world than Europe. Because of an increase globalized economy, reduced consumption here at home can mean less damage in the manufacturing countries.

Credit: 
Norwegian University of Science and Technology

World's smallest MRI performed on single atoms

image: Single magnetic atoms are deposited on a surface of magnesium oxide. They are imaged by the magnetic tip of a scanning tunneling microscope which also allows researchers to perform an MRI scan of the atom's magnetic field.

Image: 
Philip Willke et al

Researchers at the Center for Quantum Nanoscience (QNS) within the Institute for Basic Science (IBS) at Ewha Womans University have made a major scientific breakthrough by performing the world's smallest magnetic resonance imaging (MRI). In an international collaboration with colleagues from the US, QNS scientists used their new technique to visualize the magnetic field of single atoms.

An MRI is routinely done in hospitals nowadays as a part of imaging for diagnostics. MRI's detect the density of spins - the fundamental magnets in electrons and protons - in the human body. Traditionally, billions and billions of spins are required for an MRI scan. The new findings, published today in the journal Nature Physics, show that this process is now also possible for an individual atom on a surface. To do this, the team used a Scanning Tunneling Microscope, which consists of an atomically sharp metal tip that allows researchers to image and probe single atoms by scanning the tip across the surface.

The two elements that were investigated in this work, iron and titanium, are both magnetic. Through precise preparation of the sample, the atoms were readily visible in the microscope. The researchers then used the microscope's tip like an MRI machine to map the three-dimensional magnetic field created by the atoms with unprecedented resolution. In order to do so, they attached another spin cluster to the sharp metal tip of their microscope. Similar to everyday magnets, the two spins would attract or repel each other depending on their relative position. By sweeping the tip spin cluster over the atom on the surface, the researchers were able to map out the magnetic interaction. Lead author, Dr. Philip Willke of QNS says: "It turns out that the magnetic interaction we measured depends on the properties of both spins, the one on the tip and the one on the sample. For example, the signal that we see for iron atoms is vastly different from that for titanium atoms. This allows us to distinguish different kinds of atoms by their magnetic field signature and makes our technique very powerful."

The researchers plan to use their single-atom MRI to map the spin distribution in more complex structures such as molecules and magnetic materials. "Many magnetic phenomena take place on the nanoscale, including the recent generation of magnetic storage devices." says Dr. Yujeong Bae also of QNS, a co-author in this study. "We now plan to study a variety of systems using our microscopic MRI." The ability to analyze the magnetic structure on the nanoscale can help to develop new materials and drugs. Moreover, the research team wants to use this kind of MRI to characterize and control quantum systems. These are of great interest for future computation schemes, also known as quantum computing.

 "I am very excited about these results. It is certainly a milestone in our field and has very promising implications for future research." says Prof. Andreas Heinrich, Director of QNS. "The ability to map spins and their magnetic field with previously unimaginable precision, allows us to gain deeper knowledge about the structure of matter and opens new fields of basic research."

The Center for Quantum Nanoscience, on the campus of Ewha Womans University in Seoul, South Korea, is a world-leading research center merging quantum and nanoscience to engineer the quantum future through basic research. Backed by Korea's Institute for Basic Science, which was founded in 2011, the Center for Quantum Nanoscience draws on decades of QNS Director Andreas J. Heinrich's (A Boy and His Atom, IBM, 2013) scientific leadership to lay the foundation for future technology by exploring the use of quantum behavior atom-by-atom on surfaces with highest precision.

Credit: 
Institute for Basic Science

'Oumuamua is not an alien spacecraft

image: In this artist's concept, the interstellar object 'Oumuamua is depicted as a cigar-shaped body. A new analysis strongly suggests that 'Oumuamua has a natural origin and is not an alien spacecraft.

Image: 
ESO/M. Kornmesser

On October 19, 2017, astronomers discovered the first known interstellar object to visit our solar system. First spotted by the Panoramic Survey Telescope and Rapid Response System 1 (PanSTARRS1) telescope located at the University of Hawaii's Haleakala Observatory, the object defied easy description, simultaneously displaying characteristics of both a comet and an asteroid.

Astronomers formally named the object 1I/2017 U1 and appended the common name 'Oumuamua, which roughly translates to "scout" in Hawaiian. Researchers from around the world raced to collect as much data as possible before 'Oumuamua traveled beyond the reach of Earth's telescopes. In all, they had only a few weeks to observe the strange visitor.

Early reports of 'Oumuamua's odd characteristics led some to speculate that the object could be an alien spacecraft, sent from a distant civilization to examine our star system. But a new analysis co-led by Matthew Knight, an associate research scientist in the University of Maryland Department of Astronomy, strongly suggests that 'Oumuamua has a purely natural origin. The research team reported their findings in the July 1, 2019, issue of the journal Nature Astronomy.

"We have never seen anything like 'Oumuamua in our solar system. It's really a mystery still," Knight said. "But our preference is to stick with analogs we know, unless or until we find something unique. The alien spacecraft hypothesis is a fun idea, but our analysis suggests there is a whole host of natural phenomena that could explain it."

As Knight and his colleagues summarized in their study, 'Oumuamua is red in color, similar to many small objects observed in our solar system. But that's where the familiarity ends.

'Oumuamua likely has an elongated, cigarlike shape and an odd spin pattern--much like a soda bottle laying on the ground, spinning on its side. According to Knight, its motion through our solar system is particularly puzzling. While it appeared to accelerate along its trajectory--a typical feature of comets--astronomers could find no evidence of the gaseous emissions that typically create this acceleration.

"The motion of 'Oumuamua didn't simply follow gravity along a parabolic orbit as we would expect from an asteroid," Knight said. "But visually, it hasn't ever displayed any of the cometlike characteristics we'd expect. There is no discernable coma--the cloud of ice, dust and gas that surrounds active comets--nor a dust tail or gas jets."

Knight worked with Alan Fitzsimmons, an astronomer at Queen's University Belfast in Northern Ireland, to assemble a team of 14 astronomers hailing from the U.S. and Europe. The International Space Science Institute in Bern, Switzerland, served as a virtual home base for the collaboration.

"We put together a strong team of experts in various different areas of work on 'Oumuamua. This cross-pollination led to the first comprehensive analysis and the best big-picture summary to date of what we know about the object," Knight explained. "We tend to assume that the physical processes we observe here, close to home, are universal. And we haven't yet seen anything like 'Oumuamua in our solar system. This thing is weird and admittedly hard to explain, but that doesn't exclude other natural phenomena that could explain it."

The new research paper is primarily an analysis of existing data, including a December 2017 study of 'Oumuamua's shape and spin pattern co-authored by Knight and a team of UMD astronomers. This paper, published in The Astrophysical Journal Letters, relied on data from the Discovery Channel Telescope (DCT) at the Lowell Observatory in Arizona. UMD is a scientific partner of the DCT, along with Boston University, the University of Toledo and Northern Arizona University.

Knight, Fitzsimmons and their colleagues considered a number of mechanisms by which 'Oumuamua could have escaped from its home system. For example, the object could have been ejected by a gas giant planet orbiting another star. According to theory, Jupiter may have created the Oort cloud--a massive shell of small objects at the outer edge of our solar system--in this way. Some of those objects may have slipped past the influence of the sun's gravity to become interstellar travelers themselves.

The research team suspects that 'Oumuamua could be the first of many interstellar visitors. Knight is looking forward to data from the Large Synoptic Survey Telescope (LSST), which is scheduled to be operational in 2022.

"In the next 10 years, we expect to begin seeing more objects like 'Oumuamua. The LSST will be leaps and bounds beyond any other survey we have in terms of capability to find small interstellar visitors," Knight said. "We may start seeing a new object every year. That's when we'll start to know whether 'Oumuamua is weird, or common. If we find 10-20 of these things and 'Oumuamua still looks unusual, we'll have to reexamine our explanations."

Credit: 
University of Maryland

A bacteria likely to reduce the cardiovascular risks of 1 in 2 people

image: University of Louvain conducted the first pilot study in humans to observe the impact of the bacteria Akkermansia. Results: the bacterium limits the increase of several risk factors for cardiovascular diseases, moderates the progression of pre-diabetes and reduces cholesterol levels in humans. A major discovery since one in two individuals is overweight and cardiovascular risk factors. The results are published in Nature Medicine.

Image: 
Patrice Cani, UCLouvain

In 2007, Patrice Cani (FNRS-WELBIO researcher) and his team at the Louvain Drug Research Institute of University of Louvain, in close collaboration with Willem de Vos, professor at UWageningen, discovered the beneficial effects of an intestinal bacteria, Akkermansia muciniphila (1), able to moderate the development of obesity and type 2 diabetes, in mice. In 2017, the team discovered (still in the mouse) that the use of a pasteurized form of Akkermansia leads to an even greater protection than the living bacterium regarding various cardiovascular disease risk factors such as insulin resistance, hypercholesterolemia, or the storage of fat in adipose tissue.

Following these discoveries, the UCLouvain team, in collaboration with the Cliniques universitaires Saint-Luc (2), developed a clinical study in order to administer the bacteria to humans. For this, it was necessary to develop the capacity to produce the bacterium in large quantity and to make sure that the tests would be without risk for the participants.

The UCLouvain researchers administered Akkermansia to overweight or obese volunteers, all displaying insulin resistance (pre-diabetes type 2) and metabolic syndrome, in other words, having several elevated risk factors for cardiovascular diseases. The volunteers were randomly divided into 3 groups (placebo, live bacteria and pasteurized bacteria) and were asked not to change their dietary habits or their physical activity. Akkermansia was provided as a nutritional supplement.

The primary goal of this UCLouvain study was to demonstrate the feasibility of daily ingesting Akkermansia for 3 months, without risk. Clara Depommier and Amandine Everard, UCLouvain researchers, observed excellent compliance (the supplements were easy to ingest) and tolerance (there were no side effects) in the groups taking live or pasteurized bacteria.

The conclusions are clear: the tests in humans confirm what had already been observed in mice. Ingestion of the (pasteurized) bacterium prevented the deterioration of the health status of the subjects (pre-diabetes, cardiovascular risks). Even better, the researchers observed a decrease in inflammation markers in the liver, a slight decrease in the body weight of the subjects (2.3 kg on average (3)) as well as a lowering of cholesterol levels. In contrast, the metabolic parameters (insulin resistance or hypercholesterolemia) in placebo subjects continued to deteriorate over time.

Who does it benefit? According to the WHO, one in three people die every day from cardiovascular disease worldwide. In Western countries, one in two people is overweight and has increased cardiovascular risks. This research of the UCLouvain would limit these risks and therefore potentially have an impact (limit the effects) on half of the population, if properly used.

In conclusion, this pilot study demonstrates the feasibility of administrating (pasteurized) Akkermansia bacteria to humans in the form of a food supplement and reports encouraging results on the effectiveness of the Akkermansia-based dietary supplements to reduce cardio-metabolic risk factors. These results pave the way for a large-scale study, to confirm/elaborate these first results, but also endorse the commercialization of the bacteria as food supplements, by 2021.

Credit: 
Université catholique de Louvain

Three-dimensional model illuminates key aspects of early development

image: Using a 3D model, researchers were able to simulate the moment in development when the body starts to separate into two distinct halves, here, yellow and green cells.

Image: 
Laboratory of Stem Cell Biology and Molecular Embryology at The Rockefeller University

From a biological standpoint, the earliest stages of life are the most mysterious. A developing human embryo undergoes a flurry of rapid changes, and these changes are exceedingly difficult to study because they transpire within the confines of a womb.

But with new technology, it might soon be possible to fill important gaps in our understanding of early pregnancy and development. Rockefeller scientists recently used stem cells to create a 3D model of early embryonic tissues, allowing them to simulate developmental processes as they occur in time and space. The researchers hope that this tool, whose utility they recently demonstrated in a report in Nature Cell Biology, will make it possible to further elucidate the processes that guide embryonic growth, and ultimately lead to innovations that promote healthy pregnancies.

Dimensions of development

The concept of using stem cells to model early embryonic development was first developed in labs of Ali H. Brivanlou, the Robert and Harriet Heilbrunn Professor, and Eric D. Siggia, the Viola Ward Brinning and Elbert Calhoun Brinning Professor, who published their initial research on the topic in 2014. Despite making several crucial discoveries since that time, Brivanlou and Siggia knew that his system was, in some ways, limited: conventional stem cell models are two dimensional and do not take on the actual shape of an embryo, therefore prohibiting researchers from asking key questions related to its structure.

For example, scientists are highly interested in the process by which embryos attach to the uterus--a crucial first step to a successful pregnancy. And according to Mijo Simunovic, a Simons Junior Fellow in Siggia's lab, it is practically impossible to study this complex phenomenon in a two-dimensional system.

"Attachment is inherently a 3D problem," he says.

To address this issue, Brivanlou, Siggia, and Simunovic used an interdisciplinary approach to develop a 3D model simulating an approximately fourteen-day-old human embryo--the stage of development during which a key milestone of embryonic development called "gastrulation" takes place.

"We combined several techniques--bioengineering, physics, and developmental biology--to create this model," explains Simunovic, who notes that this research would not have been possible without the unique, longstanding collaboration between the Siggia and Brivanlou labs. "We now have a 3D system that mimics not only the embryo's genetic fingerprint, but also its shape and size."

Of course, it is not enough to make a model that simply looks like a real embryo: it must also act like one. Accordingly, the researchers tested whether their system could simulate one of the most fundamental processes in animal development--a phenomenon known as symmetry breaking.

Breaking symmetry, making progress

In its earliest stage, an embryo comprises a symmetrical sphere of cells. Then, after about two weeks, this symmetry begins to disappear as the embryo takes on distinct features that will become various parts of the body.

"Symmetry breaking drives almost everything that happens during embryonic development," says Simunovic. "Our heads don't look like our feet, and that's because, at some point, the embryo breaks into two parts, anterior and posterior."

This breakage is, in fact, the first symmetry breaking of the body axis that takes place during human development, and it transpires just after attachment to the uterus. If the researchers could induce such a breakage in their model, they reasoned, then they would know that their system accurately emulated a real embryo--at least during this key period in developmental time.

To this end, the researchers exposed their model to chemical signals that, in pregnancy, are released by the placenta. Through a series of experiments, they found that the addition of a chemical known as BMP4 reliably prompts symmetry breaking.

"We added BMP4, and two days later one part of the three-dimensional culture became the future posterior, and the opposite part became the future anterior," says Simunovic.

This result has implications beyond elucidating the chemistry of a particular developmental process. Now that scientists can successfully model embryonic events in 3D, extensions of this research may be used in future studies of pregnancy complications, such as unsuccessful attachment.

"About 50 to 75 percent of embryos do not attach, creating a huge bottleneck to pregnancy," says Simunovic. "We don't know why that is, but using this model we may be able to find out."

This system, Brivanlou notes, could also be used to study inborn diseases. "We can create 3D embryonic models of genetic conditions, and follow the developmental process in real time," he says. "These models can finally advance the understanding of a wide range of diseases for which we currently have no idea where and when things begin to go wrong."

Credit: 
Rockefeller University

Danish researchers create worldwide solar energy model

image: The graphic shows the total solar energy production for all European countries in the period 2013-2017. Each tiny field represents a week's energy production: The brighter the color the more energy was produced.

Image: 
Assistant Professor Marta Victoria

Solar cells are currently the world's most talked-about renewable energy source, and for any future sustainable energy system, it is crucial to know about the performance of photovoltaic systems at local, regional and global levels. Danish researchers have just set up an historically accurate model, and all the data has been made available for anyone who wants to use it.

Solar energy is advancing in earnest throughout the whole world. Over the past three years, more photovoltaic (PV) installations have been installed globally than any other energy source, and the annual growth rate between 2010 and 2017 was as high as 24%.

In global terms, it has been predicted that solar energy will play a similar role to wind energy in the sustainable energy systems of the future, but this requires precise models for how much energy PV systems produce.

Danish researchers have now developed these models in a major research project at the Department of Engineering, Aarhus University and the results have been published in the journal Progress in Photovoltaics.

"We've collected 38 years of global solar radiation, weather and temperature data with a spatial resolution of 40 km x 40 km for the entire globe, and compared this with historical data for photovoltaic installations in Europe. Based on this, we've made a very accurate model that, at global, regional and local levels, can tell you about the performance of PV installations in a given geography, depending on the type of facility being used. This means we can look at not only a single installation, but energy production in entire countries or continents from PV installations. This is extremely important for the way in which the energy systems of the future can be combined to function optimally," says Assistant Professor Marta Victoria, who has been responsible for the project.

She continues:

"Generating cheap green energy is no longer a challenge. The price of PV installations has tumbled over the last 10-20 years, so we're now seeing huge investments in this particular energy source. The challenge is to link energy production from myriads of small installations across the landscape with a country's total energy demand and energy production from other sources, some of which is also linked across national borders."

The problem is also that the green energy system of the future depends on renewable energy sources, which in turn depend on the weather. This is why, according to Marta Victoria we need very accurate and detailed knowledge about energy production.

"PV installations will have a huge impact on the energy systems of the future, and planning systems based on models that do not take into account the outages in relation to the norm simply won't work. Therefore, this project has gathered very detailed data over time for the last 38 years for the entire globe, so that the model can be used anywhere," she says.

All the data in the model has been made readily available to everyone via Open Licence.

The project is part of the RE-Invest project, which is being funded by Innovation Fund Denmark, and which brings together a large number of Danish and international universities and companies to create the energy system of the future.

Credit: 
Aarhus University

Story tips from the Department of Energy's Oak Ridge National Laboratory, July 2019

image: ORNL and university researchers use waste soft drinks as a low-cost alternative to filter carbon dioxide emissions.

Image: 
Adam Malin/Oak Ridge National Laboratory, U.S. Dept. of Energy

Materials--Soft drink science

Oak Ridge National Laboratory has teamed with Cornell College and the University of Tennessee to study ways to repurpose waste soft drinks for carbon capture that could help cut carbon dioxide emissions. In a collaborative study, researchers used a simple chemical process on a variety of regular and diet sodas and discovered that regular sodas containing citric acid made the most efficient porous carbon structures for carbon dioxide adsorption. The unconventional approach follows interest in other low-cost feedstocks, such as banana peels and coffee grounds, for adsorbents to capture carbon dioxide emitted by power plants and other fossil-fueled industries. "Our process is unique in avoiding harsh chemicals typically used to activate carbon, resulting in eco-friendly and easily recyclable adsorbents," said ORNL's Shannon Mahurin. Transforming discarded sodas into raw materials could also bring energy and environmental solutions to waste-heavy soft drink production at facilities worldwide. [Contact: Ashley Huff, (865) 241-6451; huffac@ornl.gov]

Image 1: https://www.ornl.gov/sites/default/files/2019-06/Soda%20Science%20v3%20no%20text.jpg

Caption: ORNL and university researchers use waste soft drinks as a low-cost alternative to filter carbon dioxide emissions. Credit: Adam Malin/Oak Ridge National Laboratory, U.S. Dept. of Energy

Image 2: https://www.ornl.gov/sites/default/files/2019-06/materials-soft_drink_science_2019-p05572.jpg

Caption: ORNL's Shannon Mahurin, in collaboration with Cornell College and the University of Tennessee, discovered that regular sodas containing citric acid made the most efficient porous carbon structures for carbon dioxide adsorption. Credit: Carlos Jones/Oak Ridge National Laboratory, U.S. Dept. of Energy

Quantum--Widening the net

Scientists at Oak Ridge National Laboratory studying quantum communications have discovered a more practical way to share secret messages among three parties, which could ultimately lead to better cybersecurity for the electric grid and other energy assets. Current protocols such as quantum key distribution, a prevailing approach in cybersecurity research, are designed for only two parties and, in one instance, uses a pair of light particles called entangled photons. Securely extending quantum cryptography to three parties usually requires the difficult step of creating a three-photon entangled state. "In our experiment, we were able to add the laser source as a third active participant while only needing to produce one pair of photons," said ORNL's Brian Williams, lead author of the study published in Physical Review A. "Our method removes the need for producing a third photon, which dramatically improves operation efficiency." This finding could inspire improved security for existing and future computer networks. [Contact: Sara Shoemaker, (865) 576-9219; shoemakerms@ornl.gov]

Image: https://www.ornl.gov/sites/default/files/2019-06/2018-P04780.jpg

Caption: A new study by ORNL has revealed a more practical way to share secret messages among three parties by including the laser itself as a third active participant. Their approach could ultimately lead to better cybersecurity for the electric grid and other energy assets. Credit: Genevieve Martin/Oak Ridge National Laboratory, U.S. Dept. of Energy

Batteries--Polymers that bind

A team of researchers at Oak Ridge National Laboratory have demonstrated that designed synthetic polymers can serve as a high-performance binding material for next-generation lithium-ion batteries. Binders serve a critical role in battery performance by maintaining electrochemical balance of materials and extending battery life-span. "We demonstrated how polymers perform as a binding agent during charging and discharging of lithium-ion batteries," ORNL's Tomonori Saito said. The team discovered that stronger adhesion strength alone does not always improve binder performance. Rather, performance is significantly influenced by several factors working together during the battery's operation. "Our results indicate that rational design of polymer binders is a key enabler for high-capacity anodes in next-generation batteries," Saito said. The results, published in ACS Energy Letters, could impact batteries in future consumer electronics and electric vehicles. [Contact: Jennifer Burke, (865) 576-3212; burkejj@ornl.gov]

Image: https://www.ornl.gov/sites/default/files/2019-06/Batteries-Polymers_that_bind.png

Caption: This illustration shows how polymers perform as a binding agent during the charging and discharging states of lithium-ion batteries. Credit: Tomonori Saito/Oak Ridge National Laboratory, U.S. Dept. of Energy

Nuclear--More than the core

Researchers have developed high-fidelity modeling capabilities for predicting radiation interactions outside of the reactor core--a tool that could help keep nuclear reactors running longer. The Consortium for Advanced Simulation of Light Water Reactors, headquartered at Oak Ridge National Laboratory, has integrated the new capability into its code suite VERA, or Virtual Environment for Reactor Applications. Working with the Tennessee Valley Authority, CASL simulated the refueling of the Watts Bar Unit 1 nuclear power plant. When comparing VERA's results to the detector measurements in the ex-core--the region outside a reactor's pressure vessel--the simulation of detector response closely tracked the measured data. "Not only is this advancement more accurate than other tools, it also significantly improves the computing efficiency needed to perform these high-fidelity simulations," said ORNL's Eva Davidson. The technique will provide industry and regulators better predictions for ex-core issues of current reactors, including material degradation that could affect performance and license renewals. [Contact: Jason Ellis, (865) 241-5819; ellisjk@ornl.gov]

Image: https://www.ornl.gov/sites/default/files/2019-06/Nuclear-More_than_the_core.png

Caption: The Consortium for Advanced Simulation of Light Water Reactors' code suite VERA now offers a new capability to simulate neutron transport outside of the reactor's pressure vessel. During simulations of the Tennessee Valley Authority's Watts Bar 1 nuclear power plant, VERA calculated the expected source range detector response during eight fuel cycles. Credit: Oak Ridge National Laboratory, U.S. Dept. of Energy

Computing--Building a brain

Researchers at Oak Ridge National Laboratory are taking inspiration from neural networks to create computers that mimic the human brain--a quickly growing field known as neuromorphic computing. By replacing traditional memory and CPUs with electronic neurons and synapses, scientists aim to create systems that solve complex problems more quickly using less power. "The computing community is starting to understand that this future beyond the GPU-CPU environment is coming," ORNL's Catherine Schuman said. As scientists imagine supercomputers after ORNL's Summit, the world's fastest supercomputer, and its successor Frontier, they will look for ways to surpass power and performance limits of traditional computing. "One of those paths forward is to incorporate more novel computing architectures into the supercomputer," she said. ORNL will host the second annual International Conference on Neuromorphic Systems in Knoxville from July 23-25, bringing together government, industry and academic professionals to collaborate on neuromorphic computing.--Abby Bower [Contact: Sara Shoemaker, (865) 576-9219; shoemakerms@ornl.gov]

Image: https://www.ornl.gov/sites/default/files/2019-06/ICONS_brain.png

Caption: With applications ranging from autonomous vehicle sensing to daytime astronomy to robotics, researchers attending the ORNL-hosted ICONS conference are interested not only in novel uses of neuromorphic computing, but also in the role it might play in building future supercomputers as traditional systems hit power and performance limits. Credit: Jason B. Smith/Oak Ridge National Laboratory, U.S. Dept. of Energy

Credit: 
DOE/Oak Ridge National Laboratory

Our water cycle diagrams give a false sense of water security

image: Pictures of the earth's water cycle used in education and research throughout the world are in urgent need of updating to show the effects of human interference.

Image: 
Photo by Ben Abbott

EAST LANSING, Mich. - Pictures of the earth's water cycle used in education and research throughout the world are in urgent need of updating to show the effects of human interference, according to new analysis by an international team of hydrology experts.

Leaving humans out of the picture, the researchers argue, contributes to a basic lack of awareness of how humans relate to water on Earth - and a false sense of security about future availability of this essential and scarce resource.

The team has drawn up a new set of diagrams to promote better understanding of how our water cycle works in the 21st century. These new diagrams show human interference in nearly all parts of the cycle.

The study, published in Nature Geoscience, was carried out by a large team of experts from Michigan State University and Brigham Young University in the U.S. and the University of Birmingham (United Kingdom), along with partners in the U.S., France, Canada, Switzerland and Sweden.

It showed that, in a sample of more than 450 water cycle diagrams from around the world in textbooks, scientific literature and online, 85% showed no human interaction at all with the water cycle, and only 2% of the images made any attempt to connect the cycle with climate change or water pollution.

In addition, nearly all the examples studied depicted verdant landscapes, with mild climates and abundant freshwater - usually with only a single river basin.

"In reality, people experience many river basins in their lives, and much of the world's population never sees verdant landscapes nor abundant freshwater," says Jay Zarnetske, MSU earth and environmental scientist and co-author of the study.

The researchers argue there is an urgent need to challenge this misrepresentation and promote a more accurate and sophisticated understanding of the cycle and how it works in the 21st century. This is crucial if society is to be able to achieve global solutions to the world's many water crises.

"The water cycle diagram is iconic to science, hence why it is included in children's science literature across the world. It can be used to teach both the simplest and most complex aspects of how local and planetary earth processes occur, if the diagram is accurate. Unfortunately, we documented that most diagrams are wildly inaccurate and are not relatable to people."

"Basically, humans and their activities, such as consumption of water, changing land uses, and climate change, have been left out of our water cycling thinking and teaching, and this likely hurts society's ability to acknowledge and address the looming global water crisis," Zarnetske said.

Hence, the new diagrams drawn up by the team show a more complex picture that includes elements such as meltwater from glaciers, flood damage caused by land use changes, pollution and sea level rises.

"For the first time, the new water cycle diagram adequately reflects the importance of not just quantities of water but also water quality and pollution as key criteria for assessing water resources," said Stefan Krause, Head of the Birmingham Water Council.

Every scientific diagram involves compromises and distortions, but what the team found with the water cycle was widespread exclusion of a central concept, said Ben Abbott, Brigham Young University professor and lead author on the paper.

"You can't understand water in the 21st century without including humans," he said. "Other scientific disciplines have done a good job depicting how humans now dominate many aspects of the Earth system. It's hard to find a diagram of the carbon or nitrogen cycle that doesn't show factories and fertilizers. However, our drawings of the water cycle are stuck in the 17th century."

Better drawings won't solve the global water crisis, but they could improve awareness of how local water use and climate change have global consequences, Abbott added.

Credit: 
Michigan State University

Many grandparents' medicines not secure enough around grandchildren, poll suggests

image: A new national poll asked grandparents where they store their medications when their grandchildren are around.

Image: 
University of Michigan

ANN ARBOR, MI - Whether it's a rare treat or a weekly routine, spending time with grandchildren brightens life for many older adults. But a new poll suggests many of them could do more to reduce the risk of their medications harming their grandchild.

More than 80% of the grandparents polled say they keep their medication in the same place as usual when their grandchildren visit their house - and 72% keep them in their purse or bag when they go to visit their grandchildren.

And nearly one-third say they store their prescription medications in something other than the container they came in - with the vast majority of them using an easy-to-open container.

These practices may put children at risk of accidental poisoning if they get into their grandparent's medications, say the University of Michigan researchers involved in the poll.

And for older grandchildren, the easy access may lead to misuse of certain medicines that hold the potential for abuse - for instance pain medicines and sedatives.

The findings, from the National Poll on Healthy Aging, suggest that grandparents need more education about safe medication storage when they're around children and teens, whether for a holiday visit or a regular childcare session.

The poll, carried out by the U-M Institute for Healthcare Policy and Innovation with support from AARP and Michigan Medicine, U-M's academic medical center, asked more than 2,000 adults aged 50 to 80 questions about medication storage.

According to the federal Centers for Disease Control and Prevention, nearly 40% of children treated in emergency departments for medication-related poisoning took their grandparents' medicines.

"Prescription medicines, and even over-the-counter medicines and supplements, can harm children and teens who find them in grandma's purse or on grandpa's kitchen table," says Preeti Malani, M.D., the poll's director. "Meanwhile, opioid painkillers and sleep medicines can be diverted for recreational use by teens. No matter how old your grandchildren are, you need to think about medication safety."

Care and risk

The poll finds that two-thirds of grandparents say they provide care for their grandchildren; 42% care for them monthly and 18% care for them weekly. One in ten live with their grandchildren year-round. Just over half of all adults age 50 and over who answered the poll are grandparents, including 74% of those over age 65. In all, 86% said their grandchildren had visited them in the past year.

During those visits, the poll found, 84% of older adults don't change their routine regarding where they store their medicines. Those usual places include cupboards or cabinets (61%), countertops and tables (18%), purses or bags (7%) or other locations (15%). Only 5% said they routinely keep their medications in a locked cupboard or cabinet.

And when grandparents visit their grandchildren, the chance of easy access may go up, the poll suggests. Nearly three-quarters of grandparents say they keep their medicines in their bag, and 7% leave them on a counter or table. Only 7% placed them in a locked cupboard or cabinet.

"We know that grandparents love spending time with their grandkids. A few simple steps can keep those little ones safe when you're together," says Alison Bryant, Ph.D., senior vice president of research for AARP. "Don't leave medications in your purse or on a kitchen counter--it's best to keep them locked up. It's also a good idea to go through your medications every few months and safely discard any that are expired or no longer needed."

Containers matter

Malani notes that childproof prescription drug vials and bottles were developed and required starting years ago, specifically to protect children from accidentally swallowing medicine not prescribed to them. Those "childproof" containers, however, can be hard for some adults to open. So the poll asked grandparents if they ever used alternate containers -- ones that could be easier for children to open.

Twenty-nine percent of the older adults polled said they transferred their prescription medicines to other types of containers. Slightly lower percentages did the same for supplements and over-the-counter medicines, which can also harm children especially when taken in larger than recommended amounts.

"If you put your pills into day-of-the-week pill sorters so you can remember whether you took your medicine each day, that's great - but keep that sorter out of the reach of little ones," says Malani. "Make sure you explain to them, and their parents or older siblings, that it's important to stay away from your medicines - that those pills are for you and you alone." She also notes that grandparents should make sure to have the national Poison Control number, 1-800-222-1222, stored in their phone, memorized or available.

Credit: 
Michigan Medicine - University of Michigan

Space Weather causes years of radiation damage to satellites using electric propulsion

image: Trajectories of two satellites (SES-15 and ABS-2A) undergoing electric orbit raising. The color coding indicates the number of days after launch. Geostationary orbit is indicated by a yellow dashed line.

Image: 
Lozinski et al., 2019

The use of electric propulsion for raising satellites into geostationary orbit can result in significant solar cell degradation according to a new study. The extended journey results in greater exposure to the damaging effects of space weather. Understanding the size of this risk is essential for commercial operators to take steps to mitigate the effects and protect their assets.

The new research by British Antarctic Survey, University of Cambridge, and DH Consultancy - published this month in the journal Space Weather - is being presented at the Royal Astronomical Society's National Astronomy Meeting today (1 July 2019).

The study concludes that after a radiation storm, maximum solar cell output power could be reduced by up to 8% by the time satellites reach their target destination using electric orbit raising. This is equivalent to the level of damage that would be expected after spending around 15 years at geostationary orbit.

During a radiation storm, charged particles released by the Sun become trapped within Earth's magnetic field, forming the Van Allen radiation belts which encircle Earth, and collisions with these charged particles causes damage to the solar cells. This degradation is up to 8% of output power in a worst-case scenario, but even in a quiet environment, the study predicts a 1-3% reduction in output.

Lead author Alexander Lozinski, a space weather scientist at the British Antarctic Survey (BAS), comments:

"Now we understand the level of damage caused by a slower journey into geostationary orbit, commercial satellite operators can plan optimal routes during the mission design and planning phases to ensure the best lifespan for their products".

In the last four years commercial satellite missions have begun to employ the use of electric propulsion for orbit raising. Without the need to carry chemical propellant onboard, satellite size and mass can be reduced, resulting in significant cost savings. Reducing the size of satellites could make it possible to launch two spacecraft on the same rocket (almost halving the cost of launch). Alternatively, the savings in mass could be used to accommodate additional/larger payloads, enabling increased revenue or greater technical capability.

In a conventional launch the satellite is placed into a geostationary transfer orbit by the launch vehicle and uses chemical propellants to reach geosynchronous orbit. This orbital transfer manoeuvre typically takes a few days. However, when (solely) electric propulsion is used, it can take up to 200 days to reach the target orbit due to lower thrust. This results in satellites spending a longer in the Van Allen belts, where they are exposed to the harmful effects of space radiation.
"We studied three different types of orbit raising and found that although 8% degradation is very high, careful choice of orbit and shielding can reduce this to an acceptable level," says Lozinski.

"For example, transfer orbits with a high initial apogee (maximum altitude) allow satellites to pass through regions where trapped protons are present, at greater speed, reducing the level of damage from radiation."

"Commercial satellites with all-electric propulsion were first introduced in 2015" says Professor Richard Horne, Head of the Space Weather team at BAS. "We never expected such a large reduction in power from a radiation storm. The good thing is that this study will help the satellite industry to plan the best orbit which reduces radiation damage".

Credit: 
Royal Astronomical Society

Insects inspire greener, cheaper membranes for desalination

image: The membrane's pores entrap air upon immersion in water, separating the liquids on either side and allowing the transport of only pure water vapour from the hot to the cold side.

Image: 
© 2019 Ivan Gromicho

A new membrane made from water-wet materials has specially designed gas-entrapping pores that allow it to simultaneously separate hot, salty from cool, pure water while facilitating the transfer of pure vapor from one side to the other. This principle, designed by KAUST researchers, could lead to greener, cheaper desalination membranes.

Currently, super-water-repellent perfluorocarbon membranes are popularly used for a desalination process known as membrane distillation (MD). But perfluorocarbons are expensive, nonbiodegradable and vulnerable to fouling and damage at higher temperatures, explains KAUST postdoctoral fellow Ratul Das.

With the aim of developing perfluorocarbon-free alternatives, Himanshu Mishra and his team of researchers at KAUST's Water Desalination and Reuse Center drew inspiration from two insects: springtails that live in wet soils and seaskaters that live in open oceans. Both have mushroom-shaped microtextures covering their cuticles and hairs that can spontaneously entrap life-sustaining air if the insects become submerged in water. "We mimicked those features onto water-wet (nonwater resistant) materials. The resulting surfaces robustly entrap air upon immersion in liquids. The idea of gas-entrapping membranes was born," says Mishra.

Mishra's team developed protocols for creating vertical pores within thin sheets. The diameters of the pore inlets and exits were abruptly smaller than the pore channels. "We began by toying with thin wafers of silicon to develop pores with these reentrant edges," says Mishra. "These edges prevent liquids from intruding into the pores," he explains. "We were able to achieve the function of perfluorinated membranes by harnessing this bio-inspired texture using water-wet materials, which might seem to defy conventional wisdom." When a silicon membrane with simple cylindrical pores is immersed in water, it is completely filled within 1 second. Silica gas-entrapping membranes (GEMs), on the other hand, trap air robustly within their pores when immersed in water, and can remain intact for more than six weeks.

The team then explored applying the same principle to a cheaper, easily manufactured water-wet material called poly(methyl methacrylate) (PMMA), explains Sankara Arunachalam, a research technician in Mishra's team. "PMMA-GEMs robustly separated streams of hot, salty feed from cold water for more than 90 hours with a salt rejection of 100 percent," he says.

"To our knowledge, this is the first-ever demonstration of MD membranes derived from intrinsically wetting materials," says Mishra. "The benefits are obvious: common water-wet plastics, such as PMMA, are significantly cheaper than perfluorinated ones, are environmentally friendly, and can withstand harsher operational conditions. Interdisciplinary investigations are needed to assess the scalability and reliability of this approach."

The findings could unlock the potential of common water-wet materials for greener, cheaper desalination.

Credit: 
King Abdullah University of Science & Technology (KAUST)

MS patients at a greater risk of cancer, new study suggests

image: Fifth European Academy of Neurology (EAN) congress in Oslo.

Image: 
European Academy of Neurology (EAN)

(Oslo, Saturday, 29 June, 2019) New results of a 65-year follow-up study of nearly 7,000 Norwegian patients with Multiple Sclerosis (MS) suggest that patients may have a greater overall risk of developing cancer than the general population, with an especially high risk of cancer in respiratory organs, urinary organs and the central nervous system.

Presented today at the 5th European Academy of Neurology (EAN) Congress in Oslo, Norway, the Norwegian study also indicated an increased risk of developing haematological cancers in non-MS siblings of MS patients, compared with both MS patients and the general population.

Cancer risk among MS patients compared to the non-MS population:

Respiratory cancer: 66% increase in risk

Central nervous system (CNS): 52% increase in risk

Urinary cancer: 51% increase in risk

Overall cancer: 14% increase in risk

This long-term analysis was based on patient records from 6,883 MS patients born between 1930-1979, who were registered with various Norwegian MS and Cancer Registries, and prevalence studies from Norway. The analysis also included data from 8,918 siblings without MS, and 37,919 non-MS individuals.

"This study is the first to compare cancer risk in MS with non-affected siblings of MS patients. The risk assessment between these two groups is extremely interesting because they share the same genetics and environmental conditions," noted Dr Nina Grytten, lead researcher of the study, from Haukeland University Hospital, Bergen, who presented the results at the EAN congress.

"Previous clinical studies of cancer risk in MS patients in various countries have shown inconsistent findings, so further research is needed to help improve our understanding in this area," stated Dr Grytten. "This research outlines the need for greater awareness of cancer risk among MS patients, which should lead to shortened cancer diagnosis and more effective therapy in order to improve outcomes and survival."

"Additional research could also identify the possible connections between haematological cancer and MS and new ways in which we could manage these conditions", she added.

Multiple sclerosis is a lifelong disease that affects the central nervous system, especially the brain, spinal cord and optic nerves. It can lead to a wide range of symptoms, including problems with vision, arm or leg movement, sensation or balance. MS is one of the most common causes of disability in younger adults, and people with MS have on average 7 years shorter longevity.

Haematological cancer is a type of blood cancer that includes myeloma, lymphoma and leukaemia. There are many different types of haematological cancers, which can affect the blood, bone marrow and lymph nodes in the body. According to Dr. Grytten, the results of the investigation might suggest that MS and haematological cancer could share a common etiology, which can be important for future treatment of MS and prevention of both diseases.

Credit: 
Spink Health

Atomic 'patchwork' using heteroepitaxy for next generation semiconductor devices

image: (a) Red and blue are different metal atoms; yellow are chalcogen atoms. (b) Newly developed procedure. Different TMDC precursors are fed in sequentially to grow crystalline domains with different composition.

Image: 
Tokyo Metropolitan University

Tokyo, Japan - Researchers from Tokyo Metropolitan University have grown atomically thin crystalline layers of transition metal dichalcogenides (TMDCs) with varying composition over space, continuously feeding in different types of TMDC to a growth chamber to tailor changes in properties. Examples include 20nm strips surrounded by different TMDCs with atomically straight interfaces, and layered structures. They also directly probed the electronic properties of these heterostructures; potential applications include electronics with unparalleled power efficiency.

Semiconductors are indispensable in the modern age; silicon-based integrated circuits underpin the operation of all things digital, from discrete devices like computers, smartphones and home appliances to control components for every possible industrial application. A broad range of scientific research has been directed to the next steps in semiconductor design, particularly the application of novel materials to engineer more compact, efficient circuitry which leverages the quantum mechanical behavior of materials at the nanometer length scale. Of special interest are materials with a fundamentally different dimensionality; the most famous example is graphene, a two-dimensional lattice of carbon atoms which is atomically thin.

Transition metal dichalcogenides (or TMDCs) are promising candidates for incorporation into new semiconductor devices. Composed of transition metals like molybdenum and tungsten and a chalcogen (or Group 16 element) like sulfur or selenium, they can form layered crystalline structures whose properties change drastically when the metallic element is changed, from normal metals to semiconductors, even to superconductors. By controllably weaving domains of different TMDCs into a single heterostructure (made of domains with different composition), it may be possible to produce atomically thin electronics with distinct, superior properties to existing devices.

A team led by Dr. Yu Kobayashi and Associate Professor Yasumitsu Miyata from Tokyo Metropolitan University has been at the cutting edge of efforts to create two-dimensional heterostructures with different TMDCs using vapor-phase deposition, the deposition of precursor material in a vapor state onto a surface to make atomically flat crystalline layers. One of the biggest challenges they faced was creating a perfectly flat interface between different domains, an essential feature for getting the most out of these devices. Now, they have succeeded in engineering a continuous process to grow well-defined crystalline strips of different TMDCs at the edge of existing domains, creating strips as thin as 20nm with a different composition. Their new process uses liquid precursors which can be sequentially fed into a growth chamber; by optimizing the growth rate, they were able to grow heterostructures with distinct domains linked perfectly over atomically straight edges. They directly imaged the linkage using scanning tunneling microscopy (STM), finding excellent agreement with first-principles numerical simulations of what an ideal interface should look like. The team used four different TMDCs, and also realized a layer-on-layer heterostructure.

By creating atomically sharp interfaces, electrons may be effectively confined to one-dimensional spaces on these 2D devices, for exquisite control of electron transport and resistivity as well as optical properties. The team hopes that this may pave the way to devices with unparalleled energy efficiency and novel optical properties.

Credit: 
Tokyo Metropolitan University

Pig-Pen effect: Mixing skin oil and ozone can produce a personal pollution cloud

image: When ozone hits oils on skin and in dirty clothes, it can produce a personal cloud of irritants.

Image: 
Penn State

When ozone and skin oils meet, the resulting reaction may help remove ozone from an indoor environment, but it can also produce a personal cloud of pollutants that affects indoor air quality, according to a team of researchers.

In a computer model of indoor environments, the researchers show that a range of volatile and semi-volatile gases and substances are produced when ozone, a form of oxygen that can be toxic, reacts with skin oils carried by soiled clothes, a reaction that some researchers have likened to the less-than-tidy Peanuts comic strip character.

"When the ozone is depleted through human skin, we become the generator of the primary products, which can cause sensory irritations," said Donghyun Rim, assistant professor of architectural engineering and an Institute for CyberScience associate, Penn State. "Some people call this higher concentration of pollutants around the human body the personal cloud, or we call it the 'Pig-Pen Effect.'"

The substances that are produced by the reaction include organic compounds, such as carbonyls, that can irritate the skin and lungs, said Rim. People with asthma may be particularly vulnerable to ozone and ozone reaction products, he said.

According to the researchers, who reported their findings in a recent issue of Nature's Communications Chemistry, skin oils contain substances, such as squalene, fatty acids and wax esters. If a person wears the same clothes too long -- for example, more than a day -- without washing, there is a chance that the clothes become more saturated with the oils, leading to a higher chance of reaction with ozone, which is an unstable gas.

"Squalene can react very effectively with ozone," said Rim. "Squalene has a higher reaction rate with ozone because it has a double carbon bond and, because of its chemical makeup, the ozone wants to jump in and break this bond."

Indoors, ozone concentration can range from 5 to 25 parts per billion -- ppb -- depending on how the air is circulating from outside to inside and what types of chemicals and surfaces are used in the building. In a polluted city, for example, the amount of ozone in indoor environments may be much higher.

"A lot of people think of the ozone layer when we talk about ozone," said Rim. "But, we're not talking about that ozone, that's good ozone. But ozone at the ground level has adverse health impacts."

Wearing clean clothes might be a good idea for a lot of reasons, but it might not necessarily lead to reducing exposure to ozone, said Rim. For example, a single soiled t-shirt helps keep ozone out of the breathing zone by removing about 30 to 70 percent of the ozone circulating near a person.

"If you have clean clothes, that means you might be breathing in more of this ozone, which isn't good for you either," said Rim.

Rim said that the research is one part of a larger project to better understand the indoor environment where people spend most of their time.

"The bottom line is that we, humans, spend more than 90 percent of our time in buildings, or indoor environments, but, as far as actual research goes, there are still a lot of unknowns about what's going on and what types of gases and particles we're exposed to in indoor environments," said Rim. "The things that we inhale, that we touch, that we interact with, many of those things are contributing to the chemical accumulations in our body and our health."

Rather than advising people whether to wear clean or dirty clothes, the researchers suggest that people should focus on keeping ground ozone levels down. Better building design and filtration, along with cutting pollution, are ways that could cut the impact of the Pig-Pen Effect, they added.

To build and validate the models, the researchers used experimental data from prior experiments investigating reactions between ozone and squalene, and between ozone and clothing. The researchers then analyzed further how the squalene-ozone reaction creates pollutants in various indoor conditions.

The team relied on computer modeling to simulate indoor spaces that vary with ventilation conditions and how inhabitants of those spaces manage air quality, Rim said.

In the future, the team may look at how other common indoor sources, such as candle and cigarette smoke, could affect the indoor air quality and its impact on human health.

Credit: 
Penn State

Scientists find thirdhand smoke affects cells in humans

image: Prue Talbot (left) is seen here with her graduate student Giovanna Pozuelos.

Image: 
Stan Lim, UC Riverside

RIVERSIDE, Calif. -- Thirdhand smoke can damage epithelial cells in the respiratory system by stressing cells and causing them to fight for survival, a research team led by scientists at the University of California, Riverside, has found. The finding could assist physicians treating patients exposed to thirdhand smoke.

"Our data show that cells in humans are affected by thirdhand smoke," said Prue Talbot, a professor in the Department of Molecular, Cell and Systems Biology, who led the research. "The health effects of THS, have been studied in cultured cells and animal models, but this is the first study to show a direct effect of thirdhand smoke on gene expression in humans."

Study results appear in JAMA Network Open.

Thirdhand smoke, or THS, results when exhaled smoke and smoke emanating from the tip of burning cigarettes settles on surfaces such as clothing, hair, furniture, and cars. Not strictly smoke, THS refers to the residues left behind by smoking.

"THS can resurface into the atmosphere and can be inhaled unwillingly by nonsmokers," said Giovanna Pozuelos, the first author of the research paper and a graduate student in Talbot's lab. "It has not been widely studied, which may explain why no regulations are in place to protect nonsmokers from it."

The researchers obtained nasal scrapes from four healthy nonsmokers who had been exposed to THS for three hours in a laboratory setting at UC San Francisco. The UCR researchers then worked to get good quality RNA from the scrapes -- necessary to examine gene expression changes. RNA sequencing identified genes that were over- or under-expressed. They found 382 genes were significantly over-expressed; seven other genes were under-expressed. They then identified pathways affected by these genes.

"THS inhalation for only three hours significantly altered gene expression in the nasal epithelium of healthy nonsmokers," Pozuelos said. "The inhalation altered pathways associated with oxidative stress, which can damage DNA, with cancer being a potential long-term outcome. It's extremely unlikely a three-hour exposure to THS would cause cancer, but if someone lived in an apartment or home with THS or drove a car regularly where THS was present, there could be health consequences."

Because gene expression in the nasal epithelium is similar to the bronchial epithelium, the researchers note that their data is relevant to cells deeper in the respiratory system. In the samples they studied, the researchers also found that brief THS exposure affected mitochondrial activity. Mitochondria are organelles that serve as the cell's powerhouses. If left unchecked, the observed effects would lead to cell death.

Pozuelos explained that the team focused on the nasal epithelium because the nasal passage is one way THS can enter people's lungs. The other common exposure route is through the skin, which the researchers did not study, but plan to in the future.

Already, the researchers are working with groups in San Diego, California, and Cincinnati to study long-term exposure to THS, made possible with access to homes where people are being exposed to THS.

"Many people do not know what THS is," said Talbot, the director of the UCR Stem Cell Center. "We hope our study raises awareness of this potential health hazard. Many smoking adults think, 'I smoke outside, so my family inside the house will not get exposed.' But smokers carry chemicals like nicotine indoors with their clothes. It's important that people understand that THS is real and potentially harmful."

Credit: 
University of California - Riverside