Wildfires can cause dangerous debris flows

Study highlights need for more robust hazard forecasting systems

UNIVERSITY OF CALIFORNIA - RIVERSIDE

Research News 

IMAGE: HOUSE DAMAGED BY DEBRIS FLOWS GENERATED IN LOS ANGELES COUNTY'S MULLALLY CANYON IN RESPONSE TO A RAINSTORM ON FEBRUARY 6, 2010. view more 

CREDIT: SUSAN CANNON/USGS

Wildfires don't stop being dangerous after the flames go out. Even one modest rainfall after a fire can cause a deadly landslide, according to new UC Riverside research.

"When fire moves through a watershed, it creates waxy seals that don't allow water to penetrate the soil anymore," explained environmental science doctoral student and study author James Guilinger.

Instead, the rainwater runs off the soil surface causing debris flows, which are fast-moving landslides that usually start on steep hills and accelerate as they move.

"The water doesn't behave like water anymore, it's more like wet cement," Guilinger said. "It can pick up objects as big as boulders that can destroy infrastructure and hurt or even kill people, which is what happened after the 2018 Thomas fire in Montecito."

Guilinger and his team of mentors and collaborators wanted to understand in detail how multiple storm cycles affect an area that's been burned by wildfire, since Southern California tends to have much of its rain in the same season.

The team headed to the burn scar caused by the 23,000-acre Holy Fire near Lake Elsinore to observe this phenomenon, and their results have recently been published in the Journal of Geophysical Research: Earth Surface.

"It's only recently that technology has advanced to the point that we can directly monitor soil erosion at extremely small scales," said Andrew Gray, assistant professor of watershed hydrology and Guilinger's advisor. Gray's laboratory works to understand how wildfire impacts the movement of water and sediment through landscapes after wildfire.

Even with the latest technology, the data was not easy to obtain. To deploy their ground-based laser scanner, which uses visible and infrared waves to reconstruct surfaces down to millimeter accuracy, the scientists had to climb steep hill slopes. They also deployed drones in collaboration with Nicolas Barth, assistant professor of geomorphology, in order to zoom out and see up to 10 hectares of land after the storms.

What they found is that most of the soil in channels at the bottom of valleys between hill slopes eroded during the first few rains, even though the rains were relatively modest. The channels fill with material during the years between fires as well as in response to fire, with rain then causing rapid erosion resulting in the debris flows.

"This proves the first storm events that strike an area are the most critical," Guilinger said. "You can't really mitigate them at the source. Instead, people downstream need to be aware of the dangers, and land managers need hazard modeling tools to help them respond effectively and create a plan to catch the sediment as it flows."

U.S. Geological Survey models incorporate widely available 10-meter data for watershed slopes and information about burn severity from satellite images to estimate the probability and magnitude of debris flow that would occur under a given amount of rainfall.

However, elevation data at the 1-meter scale is becoming more widely available in fire-prone areas like California. This more refined data could allow the researchers to extract finer-scale information, such as variations in hill slope gradient and the shape of water channels that may play a large role in controlling debris flows.

"We can use data like these and the results of studies like ours to inform dynamically updating hazard models in the future," Guilinger said. "Rather than have a single set of predictions for the entire wet season, we may be able to update these models after each storm."

Guilinger plans to use funding from the federal Joint Fire Science Program to improve upon existing hazard models.

"This could prove very useful to land managers either immediately affected by or planning to mitigate the dangerous aftermath of wildfires," he said.

Time lapse images of a 2019 debris flow in the burn scar of the Holy Fire near Lake Elsinore.

 

Study finds field of forensic anthropology lacks diversity

Pathways for success for students and practitioners from diverse backgrounds needs to be created

BOSTON UNIVERSITY SCHOOL OF MEDICINE

Research News

 

(Boston)--The field of forensic anthropology is a relatively homogenous discipline in terms of diversity (people of color, LGBTQ+ individuals, people with mental and physical disabilities, etc.) and this is highly problematic for the field of study and for most forensic anthropologists.

At the core of the forensic sciences are basic sciences and the STEM fields, which have struggled with increasing diversity and inclusion. The lack of diversity in the STEM fields and the forensic sciences is concerning because it can limit the types of questions being asked in research.

"As forensic practitioners, we do not reflect the demographics of the highly dynamic populations that we serve across the country. Relevant and successful research relies on a diversity of ideas, perspectives and experiences, and without such diversity, the field stagnates and does not keep up with important issues that are relevant to society," explained corresponding author Sean Tallman, PhD, RPA, assistant professor of anatomy and neurobiology at Boston University School of Medicine (BUSM).

In order to explore the demographics of the forensic anthropological community and perceptions of diversity and inclusion, an anonymous survey was sent out to the Anthropology Section of the American Academy of Forensic Sciences (AAFS), which included more than 500 individuals. The survey consisted of 48 questions that asked about demographic information; whether participants believe that diversity exists in various educational contexts; their experience with diversity, inclusion, and harassment at the AAFS annual meetings; and what the field could do to increase diversity and inclusion.

The data then was analyzed for trends in order to propose actionable measures that could produce meaningful change that positively impacts diversity and inclusion in forensic anthropology. According to the researchers they found many forensic anthropologists had experienced or witnessed discriminatory behavior within the AAFS, which is the scientific society that most forensic practitioners maintain membership in the U.S. "Problematically, many individuals in forensic anthropology do not know how to report incidents of discrimination or harassment that occur at the AAFS," added Tallman.

While the discipline has been slow to address issues of diversity, inclusion and discrimination, Tallman believes the field can mitigate these issues through regular tracking of membership demographics by the AAFS, reassessing graduate admission requirements and indicators of success, creating mechanisms for reporting discrimination and harassment, targeted outreach, and developing mentorship opportunities.

"Striving for a culture of diversity through inclusion in forensic anthropology helps to reflect the greater populations that we serve and encourages us to challenge our own assumptions and inherent biases that can complicate the analysis of skeletal remains in forensic casework. Diversity and inclusion initiatives should be substantial and well-supported, rather than merely token gestures to increase the number of minorities or underrepresented groups."

###

These findings appear online in the journal Forensic Anthropology.

Seeing no longer believing: the manipulation of online images

Online images are not always what they seem, especially on social media

QUEENSLAND UNIVERSITY OF TECHNOLOGY

Research News

IMAGE: A MANIPULATED IMAGE SHARED WIDELY ON SOCIAL MEDIA DURING THE 2019-2020 AUSTRALIAN BUSHFIRES. view more 

CREDIT: DR T.J. THOMSON, QUT'S DIGITAL MEDIA RESEARCH CENTRE

A peace sign from Martin Luther King, Jr, becomes a rude gesture; President Donald Trump's inauguration crowd scenes inflated; dolphins in Venice's Grand Canal; and crocodiles on the streets of flooded Townsville - all manipulated images posted as truth.

Image editing software is so ubiquitous and easy to use, according to researchers from QUT's Digital Media Research Centre, it has the power to re-imagine history.

And, they say, deadline-driven journalists lack the tools to tell the difference, especially when the images come through from social media.

Their study, Visual mis/disinformation in journalism and public communications, has been published in Journalism Practice. It was driven by the increased prevalence of fake news and how social media platforms and news organisations are struggling to identify and combat visual mis/disinformation presented to their audiences.

"When Donald Trump's staff posted an image to his official Facebook page in 2019, journalists were able to spot the photoshopped edits to the president's skin and physique because an unedited version exists on the White House's official Flickr feed," said lead author Dr T.J. Thomson.

"But what about when unedited versions aren't available online and journalists can't rely on simple reverse-image searches to verify whether an image is real or has been manipulated?

"When it is possible to alter past and present images, by methods like cloning, splicing, cropping, re-touching or re-sampling, we face the danger of a re-written history - a very Orwellian scenario."

Examples highlighted in the report include photos shared by news outlets last year of crocodiles on Townsville streets during a flood which were later shown to be images of alligators in Florida from 2014. It also quotes a Reuters employee on their discovery that a harrowing video shared during Cyclone Idai, which devastated parts of Africa in 2019, had been shot in Libya five years earlier.

An image of Dr Martin Luther King Jr's reaction to the US Senate's passing of the civil rights bill in 1964, was manipulated to make it appear that he was flipping the bird to the camera. This edited version was shared widely on Twitter, Reddit, and white supremacist website The Daily Stormer.

Dr Thomson, Associate Professor Daniel Angus, Dr Paula Dootson, Dr Edward Hurcombe, and Adam Smith have mapped journalists' current social media verification techniques and suggest which tools are most effective for which circumstances.

"Detection of false images is made harder by the number of visuals created daily - in excess of 3.2 billion photos and 720,000 hours of video - along with the speed at which they are produced, published, and shared," said Dr Thomson.

"Other considerations include the digital and visual literacy of those who see them. Yet being able to detect fraudulent edits masquerading as reality is critically important.

"While journalists who create visual media are not immune to ethical breaches, the practice of incorporating more user-generated and crowd-sourced visual content into news reports is growing. Verification on social media will have to increase commensurately if we wish to improve trust in institutions and strengthen our democracy."

Dr Thomson said a recent quantitative study performed by the International Centre for Journalists (ICFJ) found a very low usage of social media verification tools in newsrooms.

"The ICFJ surveyed over 2,700 journalists and newsroom managers in more than 130 countries and found only 11% of those surveyed used social media verification tools," he said.

"The lack of user-friendly forensic tools available and low levels of digital media literacy, combined, are chief barriers to those seeking to stem the tide of visual mis/disinformation online."

Associate Professor Angus said the study demonstrated an urgent need for better tools, developed with journalists, to provide greater clarity around the provenance and authenticity of images and other media.

"Despite knowing little about the provenance and veracity of the visual content they encounter, journalists have to quickly determine whether to re-publish or amplify this content," he said.

"The many examples of misattributed, doctored, and faked imagery attest to the importance of accuracy, transparency, and trust in the arena of public discourse. People generally vote and make decisions based on information they receive via friends and family, politicians, organisations, and journalists."

The researchers cite current manual detection strategies - using a reverse image search, examining image metadata, examining light and shadows; and using image editing software - but say more tools need to be developed, including more advanced machine learning methods, to verify visuals on social media.

###

Read the full study: https://www.tandfonline.com/doi/full/10.1080/17512786.2020.1832139

A PDF is also available.

Manipulated image of President Donald Trump (IMAGE)

QUEENSLAND UNIVERSITY OF TECHNOLOGY

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The original photo of US President Donald Trump (left) and the edited version of him (right) that he shared on his official Instagram and Facebook accounts.

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Dr T.J. Thomson, QUT's Digital Media Research Centre.

Extruded grains may be better for pigs

UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES

Research News

 

URBANA, Ill. - Extrusion is the norm in the pet and aqua feed industries, yet it remains unusual for swine feed in the United States. But the technology can improve energy and protein digestibility in pigs, according to research from the University of Illinois.

"We're not doing this much in the U.S., partly because the extrusion equipment typically is not installed in feed mills producing pig feeds. If a feed company decided they wanted to extrude diets or extrude grain by itself, as we did in this case, it would add cost. So the only way it would be economical would be if the pigs performed better with extruded grains," says Hans H. Stein, professor in the Department of Animal Sciences and the Division of Nutritional Sciences at Illinois and co-author on a study in Animal Feed Science and Technology.

Stein and his research team compared pig diets containing either extruded or unprocessed corn, wheat, and sorghum to determine ileal starch and amino acid digestibility, as well as total tract digestibility of energy and fiber. One source of each grain was ground and then divided in two batches, with one batch left as is and the other extruded in a single-screw extruder with an exit temperature of 100 degrees Celsius. Grains were ground and extruded at Kansas State University, but extrusion equipment at the new Feed Technology Center at Illinois will facilitate future research to help meet the growing global demand for animal protein.

"In extruded corn and wheat, we saw a nice improvement in amino acid digestibility. Corn in particular," Stein says. "And we observed increases for energy in extruded corn and sorghum, but not in wheat."

Starch digestibility also increased in extruded grains, compared with unprocessed grains.

"Starch is already well digested by pigs, but by extruding it, we increase its digestibility even more. And we have seen in quite a few other experiments, every time we increase starch digestibility, we increase energy digestibility," Stein says. "There's a very, very close relationship between the two."

The mechanical process of extrusion, which involves heat, pressure, and steam, leads to gelatinization of starch, which explains the link between starch and energy digestibility.

"In the extruded grains, 90% of the starch was gelatinized," Stein says. "Gelatinization opens the starch molecule, making it easier for enzymes to break down every bond within the starch. That leads to greater energy digestibility and absorption."

Fiber digestibility didn't change markedly in extruded grains versus unprocessed grains, but more of the fiber content became soluble with extrusion. "That means some of the insoluble fibers were solubilized. But because fiber digestibility didn't increase overall, that didn't have as much of an impact as we had expected," Stein says.

With pigs extracting more energy and protein from extruded grains, Stein sees a potential economic benefit that could justify the cost of adding extruding equipment to feed mills.

"If feed manufacturers can increase the energy as much as we did in our study, then there certainly is value in extruding grain for pig diets," he says.

###

The article, "Digestibility of amino acids, fiber, and energy by growing pigs, and concentrations of digestible and metabolizable energy in yellow dent corn, hard red winter wheat, and sorghum may be influenced by extrusion," is published in Animal Feed Science and Technology [DOI: 10.1016/j.anifeedsci.2020.114602]. Authors include Diego A. Rodriguez, Su A. Lee, Cassandra K. Jones, John K. Htoo, and Hans H. Stein. The research was supported by Evonik Nutrition & Care.

The Department of Animal Sciences, the Division of Nutritional Sciences, and the Feed Technology Center are part of the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois.

 PTSD and alcohol abuse go hand-in-hand, but males and females exhibit symptoms differently

In rodent experiments modeled to mimic real-life circumstances, scientists revealed brain mechanisms that could lead to targeted treatments.

SCRIPPS RESEARCH INSTITUTE

Research News

 

LA JOLLA, CA--Through intricate experiments designed to account for sex-specific differences, scientists at Scripps Research have collaborated to zero in on certain changes in the brain that may be responsible for driving alcohol abuse among people with post-traumatic stress disorder, or PTSD.

In studies with rodents, researchers found that males and females exhibit their own distinct symptoms and brain features of PTSD and alcohol use disorder. Such differences are not typically accounted for in laboratory-based studies yet could lead to more successful clinical treatments.

The findings, published in Molecular Psychiatry, also present a new model for identifying biomarkers that may indicate a person with PTSD is more likely to develop alcohol use disorder.

"Having PTSD significantly increases the risk of developing alcohol use disorder, as individuals use alcohol to cope with stress and anxiety. Yet the underlying biology of comorbid disorders is generally not well understood," says Dean Kirson, PhD, a postdoctoral fellow in neurophysiology in the lab of professor Marisa Roberto, PhD, and a co-lead author with Michael Steinman, PhD. "We hope our new knowledge of sex-specific changes in the brain will help propel the development of more targeted treatments."

About 7 percent to 8 percent of the country's population will have PTSD at some point in their life, according to the U.S. Department of Veterans Affairs. Causes include combat exposure, physical abuse, an accident or other forms of trauma. Alcohol abuse disorder is also common, affecting some 15 million people in the United States. Those with stress and anxiety disorders such as PTSD are not only more likely to abuse alcohol, but also have increased alcohol withdrawal symptoms and relapse risk.

"Most people know or will know someone struggling with one or both of these disorders and may try to help them. However, there are very few effective treatments currently," Roberto says. "Both are complex disorders that affect similar brain circuitry. My lab has been studying addiction and stress separately, so here we teamed up with the Zorrilla lab to apply a novel translationally-relevant behavioral model to examine what changes occur when these disorders are comorbid."

The joint study between Roberto and Eric Zorrilla, PhD--who are co-senior authors--examined behavior, sleep patterns, inflammatory immune responses and levels of a neurotransmitter known as GABA (short for gamma-Aminobutyric acid), which lowers anxiety and increases feelings of relaxation and is a common feature of alcohol dependence

For both male and female rats, traumatic stress and alcohol exacerbated other behaviors common in PTSD, such as social avoidance startle reactions and defensive behavior. Those who were identified as "drinking-vulnerable" prior to trauma most strongly showed avoidance of trauma-reminiscent places.

However, the scientists noted key differences in how males and females behave following trauma and saw markedly different patterns of GABA signaling. For example, males showed increased GABA receptor function, while females showed increased GABA release.

"This may be important because there is growing awareness that medicines could potentially have different levels of effectiveness in male and female patients and understanding the biology that explains why these differences exist could improve outcomes," Steinman says.

The team also found that males exhibited an immune-based biomarker--small proteins known as cytokines, which are secreted by immune cells--that determined vulnerability to alcohol use disorder. The females did not.

"We identified profiles of specific cytokines, many not previously linked to stress behaviors, that strongly related to poor drinking outcomes," says Zorilla, associate professor

In the Department of Molecular Medicine. "These may be important clinically or even mechanistically, but they were unique to males, so we have work ahead of us to find similar biomarkers for females."

The Roberto and Zorrilla labs plan to conduct additional research into the mechanisms behind the biological changes they observed and test which brain systems can be targeted to treat both PTSD and alcohol abuse.

"We also plan to further investigate the role of the immune system in these disorders," Roberto says. "These distinct biomarkers may aid in targeted treatment."

###

The study, "Importance of sex and trauma context on circulating cytokines and amygdalar GABAergic signaling in a comorbid model of posttraumatic stress and alcohol use disorders," was authored by Michael Steinman, Dean Kirson, Sarah Wolfe, Sophia Khom, Shannon D'Ambrosio, Samantha Spierling Bagsic, Michal Bajo, Roman Vlkolinský, Noah Hoang, Anshita Singhal, Suhas Sureshchandra, Christopher Oleata, Ilhem Messaoudi, Eric Zorrilla and Marisa Roberto.

Support for this study was provided by the National Institute on Alcohol Abuse and Alcoholism (AA027700, AA013498, P60 AA006420, AA017447, AA021491, AA015566, K99 AA026638 and T32 AA007456), the National Institute on Drug Abuse (R21 DA046865) and the Pearson Center for Alcoholism and Addiction Research.

 

RUDN University chemist created a catalyst from orange peel for organic compounds production

RUDN UNIVERSITY

Research News

 

IMAGE: N-HETEROCYCLES ARE ORGANIC SUBSTANCES USED IN THE CHEMICAL INDUSTRY AND MEDICINE. TO PRODUCE THEM, EXPENSIVE CATALYSTS MADE FROM NOBLE METALS ARE USED. A CHEMIST FROM RUDN UNIVERSITY DEVELOPED A NANOCATALYST... view more 

CREDIT: RUDN UNIVERSITY

N-heterocycles are organic substances used in the chemical industry and medicine. To produce them, expensive catalysts made from noble metals are used. A chemist from RUDN University developed a nanocatalyst for N-heterocycles that consists of zinc oxide and niobium and can be obtained using orange peel without any additional chemical agents. The catalyst makes the reaction almost 100% effective, thus increasing the efficiency and reducing the cost of N-heterocycles production. The results of the study were published in the Catalysis Today journal.

N-heterocycles are used in the production of plastics and medicinal drugs (quinine, morphine, pyramidon) and as dyes. Their synthesis requires the use of catalysts based on expensive noble metals such as gold, palladium, or iridium. All previous attempts to use other elements had been unsuccessful due to low efficiency or instability of the end products. However, a chemist from RUDN University developed a nanocatalyst based on cheaper metals--niobium and zinc. The new catalyst provides for almost 100% efficiency of N-heterocycle synthesis, and its precursor (or platform molecule) is levulinic acid.

"Levulinic acid is one of the top-10 most promising platform molecules that can be easily obtained from biomass. The transformation of levulinic acid into N-heterocycles has recently become a popular topic because N-heterocycles proved to be useful in the pharmaceutical, agrochemical, and polymer industries", said Rafael Luque, PhD, the head of the Molecular Design and Synthesis of Innovative Compounds for Medicine Science Center at RUDN University.

His team used a mechanochemical method to create the nanocatalyst: it means, its components were simply mixed in a special grinder without solvents or other additives. Orange peel served as a template for the catalyst preparation. Ground peel, dry zinc acetate, and 18 1-cm steel balls were put in the grinder and mixed at 350 revolutions per minute for 20 minutes. After that, the mixture was heated at 200? for two hours. As a result, zinc oxide nanoparticles were formed. Orange peel was used to give zinc acetate a surface to concentrate on, and also to help form intermediary compounds. The remains of the peel were partially removed from the mix in the course of heating. After that, zinc oxide nanoparticles were combined in the grinder with niobium-containing particles so that the concentration of the metal in the end product would reach 2.5% to 10%.

To test the new nanocatalyst, the chemists used it to transform levulinic acid into an N-heterocycle. The team selected the most efficient ratio of the catalyst: 10% of niobium to 90% of zinc oxide. In this case, almost all levulinic acid (94.5%) was turned into the end product without byproducts, and N-heterocycles accounted for 97.4% of the yield.

"This work shows that if we play with the catalyst structure, valuable compounds can be developed from biowaste. Using organic waste and eco-friendly methods, we can offer an alternative to the modern-day chemical industry that is extremely dependent on fossil fuels," added Rafael Luque.

ANOTHER POWERFUL DEGREASER, THAT CAN MELT PLASTIC; D-LEMONINE, IS AN EXTRACT OF ORANGE PEEL

D-Limonene: safety and clinical applications - PubMed

pubmed.ncbi.nlm.nih.gov › ...

D-limonene is one of the most common terpenes in nature. It is a major constituent in several citrus oils (orange, lemon, mandarin, lime, and grapefruit).

by J Sun · ‎2007 · ‎Cited by 516 · ‎Related articles

Limonene: Uses, Side Effects, Interactions, Dosage, and ...

www.webmd.com › vitamins › ingredientmono-1105

LIMONENE. OTHER NAME(S):. Alpha-Limonene, Alpha-Limonène, Dipentene, D-Limonene...

d-Limonene - To Make Your Green Cleaning Products ...

www.newdirectionsaromatics.ca › raw-materials › dlim...

d-Limonene (Citrus Terpenes) Raw Material.

Bone density is associated with regular use, study finds

BECKMAN INSTITUTE FOR ADVANCED SCIENCE AND TECHNOLOGY

Research News

 

IMAGE: KATHRYN CLANCY, RIGHT, AND KATHERINE LEE ARE INTERESTED IN STUDYING HOW DAILY ACTIVITIES INFLUENCE BONE DENSITY. view more 

CREDIT: BECKMAN INSTITUTE FOR ADVANCED SCIENCE AND TECHNOLOGY

Researchers at the University of Illinois Urbana-Champaign have studied a population of women in rural Poland for the past four years to understand how their lifestyle affects their bone density. The age group and lifestyle of these women are often overlooked in such studies.

The study "Bone density and frame size in adult women: effects of body size, habitual use, and life history" was published in the American Journal of Human Biology.

"My work focuses on understanding how our activities shape our skeleton and what it means for the modern population," said Katharine Lee, a recent graduate of the Clancy group, which is affiliated with the Beckman Institute for Advanced Science and Technology.

The study focused on a population of farmers whose lifestyles involve substantial farm and domestic labor, such as growing fruits and vegetables, churning butter, beating rugs, washing windows, and caring for children. "We made some basic body measurements and looked at the physical activity patterns of these women," Lee said. "We also used a bone sonometer, which was provided through Beckman's Biomedical Imaging Center. It is a portable device that can be conveniently used to carry out bone density measurements."

Previous studies in the field have looked at bone density measurements in menopausal women. The researchers wanted to focus on women between the ages of 18 and 46, an age group that is not often looked at in bone density studies. "We wondered why there was so little research on premenopausal women, since presumably their bone density and activity predicts postmenopausal osteoporosis," said Kathryn Clancy, an associate professor of anthropology at Illinois and a part-time Beckman faculty member.

"We saw that measures such as grip strength and lean mass are associated with the bone density and frame size of these premenopausal women. We also saw that the bone density of the radius, which is the bone at the base of your thumb, is very high compared to an average white woman of European descent," Lee said. "Interestingly, we don't see this increased bone density in Polish American women. We don't fully understand what factors are causing it."

The researchers believe that this study sheds light on the specific contexts of this lifestyle. "A lot of these measures have looked at large populations and averaged, so they have missed many of these details," Lee said. "It is also important to think about which populations are not represented in the literature and look at lifestyles that are different to the modern, sedentary lifestyle that most people in the U.S. have."

Moving forward, the researchers are interested in understanding whether the childhood environment has helped shape the bone health of the women. "We have interviewed them about the different types of work they did when they were growing up. We asked whether they grew up on a farm, whether they had farm animals, or whether they tended a garden. Those activities, rather than the ones they are doing now, might be associated with the bone health measures," Lee said.

###

Editor's note: The study "Bone density and frame size in adult women: effects of body size, habitual use, and life history" can be found at https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajhb.23502.

Bioplastics no safer than other plastics

Bioplastics may be produced from oil, but that's about the only benefit, researchers say

NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY

Research News

 

Conventional plastic is made from oil. The production of plastic is not sustainable, and it can contain substances we know are dangerous if ingested.

In recent years, bioplastics have come onto the market as an alternative to conventional plastic. Bioplastic has some apparent advantages: it is usually made from recycled material or plant cellulose, it can be biodegradable - or both.

But a new study shows that it is not non-toxic.

Bioplastics are in fact just as toxic as other plastics, according to an article recently published in Environment International.

"Bio-based and biodegradable plastic are not any safer than other plastics," says Lisa Zimmermann from Goethe Universität in Frankfurt. She is the lead author of the recent article.

Zimmermann points out  that products based on cellulose and starch contained the most chemicals. They also triggered stronger toxic reactions under laboratory conditions.

"Three out of four of these plastic products contain substances that we know are dangerous under laboratory conditions, the same as for conventional plastic," says Martin Wagner, associate professor at the Norwegian University of Science and Technology's Department of Biology.

Wagner is one of the collaborators for PlastX, a research group at the Institut für sozial-ökologische Forschung (ISOE) in Frankfurt.

This group has just led the work on the largest survey to date of chemicals in bioplastics and plastics made from plant-based materials.

They have looked at toxic substances in these types of plastic. The substances can be directly toxic to cells in the laboratory, or they can act as hormones that in turn can disturb the body's balance.

The study includes 43 different plastic products, including disposable cutlery, chocolate packaging paper, drink bottles and wine corks.

"Eighty per cent of the products contained more than 1000 different chemicals. Some of them as many as 20 000 chemicals," says Wagner.

It goes without saying that it is almost impossible to keep track of absolutely all the possible harmful effects of so many different materials.

Even seemingly similar products have their own special chemical composition. A plastic bag made of bio-polyethylene can contain completely different substances than a wine cork made of the same material.

"Making general statements about certain materials becomes almost impossible," says Wagner.

At present, the consequences this has for the environment and for people's health are still uncertain. We don't know to what extent the substances in plastic are transferable to humans.

Nor do we know whether the alternatives to bioplastics and conventional plastics are better for us and the environment around us, since so many factors come into play. The alternatives may involve polluting production methods and limited opportunities for recycling, or food production has to give way to obtain the materials for the alternative products. More research is needed.

###

Source: Lisa Zimmermann, Andrea Dombrowski, Carolin Völker, Martin Wagner (2020). Are bioplastics and plant-based materials safer than conventional plastics? In vitro toxicity and chemical composition, Environment International. https://doi.org/10.1016/j.envint.2020.106066

 

War on plastic is distracting from more urgent threats to environment, experts warn

UNIVERSITY OF NOTTINGHAM

Research News 

A team of leading environmental experts, spearheaded by the University of Nottingham, have warned that the current war on plastic is detracting from the bigger threats to the environment.

In an article published in the peer-reviewed scientific journal, Wiley Interdisciplinary Reviews (WIREs) Water, the 13 experts* say that while plastic waste is an issue, its prominence in the general public's concern for the environment is overshadowing greater threats, for example, climate change and biodiversity loss.

The interdisciplinary team argue that much of the discourse around plastic waste is based on data that is not always representative of the environments that have been sampled. The aversion to plastic associated with this could encourage the use of alternative materials with potentially greater harmful effects.

The authors warn that plastic pollution dominates the public's concern for the environment and has been exploited politically, after capturing the attention of the world, for example through emotive imagery of wildlife caught in plastic waste and alarmist headlines. They say small political gestures such as legislation banning cosmetic microplastics, taxing plastic bags, and financial incentives for using reusable containers, as well as the promotion of products as 'green' for containing less plastic than alternatives, risks instilling a complacency in society towards other environmental problems that are not as tangible as plastic pollution.

The article's authors call on the media and others to ensure that the realities of plastic pollution are not misrepresented, particularly in the public dissemination of the issue, and urges government to minimise the environmental impact of over-consumption, however inconvenient, through product design, truly circular waste-management, and considered rather than reactionary policy.

Dr Tom Stanton, a co-author who led the work while in the University of Nottingham's School of Geography and Food, Water, Waste Research Group, said: "We are seeing unprecedented engagement with environmental issues, particularly plastic pollution, from the public and we believe this presents a once in a generation opportunity to promote other, potentially greater environmental issues.

"This is a key moment in which to highlight and address areas such as 'throw-away' culture in society and overhaul waste management. However, if there is a continuation in prioritising plastic, this opportunity will be missed - and at great cost to our environment."

The article also highlights that plastics are not the only type of polluting material originating from human activity that contaminates the environment. Other examples include natural textile fibres such as cotton and wool, Spheroidal Carbonaceous Particles (remnants of fossil fuels), and brake-wear particles from vehicles - all of which are present in different places, where they may have adverse environmental effects. The authors note that these materials are often much more abundant than microplastics and some, such as glass, aluminium, paper, and natural fibres, are associated with 'plastic alternatives' that are marketed as solutions to plastic pollution, but in reality side-step the inconvenience of changing the consumption practices at the root of the problem. The eco-toxicological impacts of some of these materials are less well known than plastic and microplastic pollution, yet they could have significant impacts.

The authors conclude that that a behavioural science approach should be taken to assess society's relationship with single-use items and throw-away culture, and to overhaul waste mismanagement.

They say there is an understandable desire to minimise the global plastic debris in the environment which should not be discouraged, but positive action to minimise plastic pollution needs to be well informed and should not exacerbate or overshadow other forms of environmental degradation associated with alternative materials.

The article states that solutions are likely to come from a greater focus on designing materials and products that can be recycled, that have their end-of-life built in, and that markets and facilities exist to recycle all plastic waste.

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