. Scientific Frontline: Environmental
Showing posts with label Environmental. Show all posts
Showing posts with label Environmental. Show all posts

Monday, January 9, 2023

Jet engine lubrication oils are a major source of ultrafine particles

Lubrication oil in the hot exhaust plume of an aircraft engine can form ultrafine particles as soon as the plume cools down. This has now been corroborated in a study by Goethe University Frankfurt and the Hessian Agency for Nature Conservation, Environment and Geology.   
Photo Credit: Alexander Vogel, Goethe University Frankfurt

Measurements conducted by the Hessian Agency for Nature Conservation, Environment and Geology (HLNUG) in recent years have shown that Frankfurt International Airport is a major source of ultrafine particles and that these can disperse over long distances across the city. In collaboration with experts at the HLNUG, researchers at Goethe University Frankfurt have now discovered that ultrafine particles partly consist of synthetic jet oils. The research team has deduced that emissions from lubrication oils must be lowered in addition to those from kerosene in order to reduce the concentration of ultrafine particles and thus improve air quality.

Ultrafine particles form during combustion processes, for example when wood or biomass is burned, as well as in power and industrial plants. Alongside road traffic, large airports are a major source of these ultrafine particles, which are less than 100 millionths of a millimeter (100 nanometers) in size. Because they are so small, they can penetrate deep into the lower respiratory tract, overcome the air-blood barrier and, depending on their composition, cause inflammatory reactions in the tissue, for example. What's more, ultrafine particles are suspected of being capable of triggering cardiovascular diseases.

Friday, January 6, 2023

UCR scientists develop method to turn plastic waste into potentially valuable soil additive

Recent rain storms washed plastic waste into a creek bed in Riverside's Fairmount Park.
Photo Credit: David Danelski/UCR

University of California, Riverside, scientists have moved a step closer to finding a use for the hundreds of millions of tons of plastic waste produced every year that often winds up clogging streams and rivers and polluting our oceans.

In a recent study, Kandis Leslie Abdul-Aziz, a UCR assistant professor of chemical and environmental engineering, and her colleagues detailed a method to convert plastic waste into a highly porous form of charcoal or char that has a whopping surface area of about 400 square meters per gram of mass.

Such charcoal captures carbon and could potentially be added to soil to improve soil water retention and aeration of farmlands. It could also fertilize the soil as it naturally breaks down. Abdul-Aziz, however, cautioned that more work needs to be done to substantiate the utility of such char in agriculture.

The plastic-to-char process was developed at UC Riverside’s Marlan and Rosemary Bourns College of Engineering. It involved mixing one of two common types of plastic with corn waste — the leftover stalks, leaves, husks, and cobs — collectively known as corn stover. The mix was then cooked with highly compressed hot water, a process known as hydrothermal carbonization.

Thursday, January 5, 2023

Researchers Find that Wind Turbines Repel Bats in Finnish Forests

Northern bat (Eptesicus nilssonii) is the most common bat in Finland.
Photo Credit: Anna Blomberg

Wind turbines are built at an increasing pace but their effect on nature and animals is poorly known. Researchers from the Universities of Turku and Helsinki in Finland have investigated the impact of wind turbines on bat presence and activity in boreal forests. The results indicate clearly that bats don’t like wind turbines.

The researchers recorded bat acoustic activity for an entire summer at seven wind farms located in forests situated on the western coastline of Finland. By setting up recorders at varying distances from the wind turbines, they were able to see how bat activity and presence differed closer to the turbines as well as further away.

The researchers studied two groups of bats: the Northern bat, which is the most common species in Finland, and the Myotis, a group of five species, including the very common Daubenton’s bat.

“Our results showed that bat presence was impacted by the presence of wind turbines as both studied groups were found more often further away from the wind turbines. Northern bats were repelled up to 800 meters from the wind turbines, but for the Myotis species the negative impact of wind power was even greater than one kilometer, which was the maximum distance we studied”, summarizes lead author, Doctoral Researcher Simon Gaultier from the University of Turku.

Climate change could cause “disaster” in the world’s oceans

J. Keith Moore, UCI professor of Earth system science, says, “… unchecked global warming could lead to a shutdown of the ocean deep circulation. This would be a climate disaster similar in magnitude to complete melting of the ice sheets on land.”
Photo Credit: Steve Zylius / UCI

Climate-driven heating of seawater is causing a slowdown of deep circulation patterns in the Atlantic and Southern oceans, according to University of California, Irvine Earth system scientists, and if this process continues, the ocean’s ability to remove carbon dioxide from the atmosphere will be severely limited, further exacerbating global warming.

In a recent study published in Nature Climate Change, these researchers analyzed projections from three dozen climate models and found that the Atlantic Meridional Overturning Circulation and the Southern Meridional Overturning Circulation will slow by as much as 42 percent by 2100. The simulations suggest that under worst-case warming, the SMOC could cease entirely by 2300.

“Analysis of the projections from 36 Earth system models over a range of climate scenarios shows that unchecked global warming could lead to a shutdown of the ocean deep circulation,” said co-author J. Keith Moore, UCI professor of Earth system science. “This would be a climate disaster similar in magnitude to complete melting of the ice sheets on land.”

Antibiotic residues in water a threat to human health

Photo Credit: Thomas Hoang

Antibiotic residues in wastewater and wastewater treatment plants in regions around China and India risk contributing to antibiotic resistance, and the drinking water may pose a threat to human health, according to an analysis from Karolinska Institutet published in The Lancet Planetary Health. The researchers also determined the relative contribution of various sources of antibiotic contamination in waterways, such as hospitals, municipals, livestock, and pharmaceutical manufacturing.

” Our results can help decision-makers to target risk reduction measures against environmental residues of priority antibiotics and in high-risk sites, to protect human health and the environment,” says Nada Hanna, researcher at the Department of Global Public Health at Karolinska Institutet, and the study’s first author. “Allocating these resources efficiently is especially vital for resource-poor countries that produce large amounts of antibiotics.”

Bacteria that become resistant to antibiotics are a global threat that can lead to untreatable bacterial infections in animals and humans.

Antibiotics can enter the environment during their production, consumption and disposal. Antibiotic residues in the environment, such as in wastewater and drinking water, can contribute to the emergence and spread of resistance.

Wednesday, January 4, 2023

Reef fish must relearn 'rules of engagement' after coral bleaching

butterfly fish
Photo Credit: Светлана

Mass coral bleaching events are making it harder for some species of reef fish to identify competitors, new research reveals.

Scientists studying reefs across five Indo-Pacific regions found that the ability of butterfly fish individuals to identify competitor species and respond appropriately was compromised after widespread loss of coral caused by bleaching.

This change means they make poorer decisions that leave them less able to avoid unnecessary fights, using up precious limited energy. The scientists behind the study believe these changes could have implications for species survival as further global warming increases the likelihood of coral loss.

“By recognizing a competitor, individual fish can make decisions about whether to escalate, or retreat from, a contest—conserving valuable energy and avoiding injuries,” said Sally Keith, a senior lecturer in marine biology at Lancaster University and lead author of the study.

Researchers detect fluoride in water with new simple color change test

Photo Credit: Henryk Niestrój

Test is first to use artificial cell sensors to detect environmental contaminant

A team of synthetic biologists at Northwestern is developing a sensor platform that will be able to detect a range of environmental and biological targets in real-world samples.

Environmental contaminants like fluoride, lead and pesticides exist all around and even within us. While researchers have simple ways to measure concentrations of such contaminants inside lab environments, levels are much more difficult to test in the field. That’s because they require costly specialized equipment.

Recent efforts in synthetic biology have leveraged cellular biosensors to both detect and report environmental contaminants in a cost-effective and field-deployable manner. Even as progress is being made, scientists have struggled to answer the question of how to protect sensor components from substances that naturally exist in extracted samples.

Tuesday, January 3, 2023

Fewer moths, more flies

Insects such as the bumblebee hoverfly Volucella bombylans appear much less frequently than before.
Photo Credit: Carolien van Oijen

The complex relationships between plants and their pollinators have changed dramatically across the last century

In the far north of the planet, climate change is clearly noticeable. A new study in Finland now shows that in parallel there have been dramatic changes in pollinating insects. Researchers from the Martin Luther University Halle-Wittenberg (MLU), the Helmholtz Centre for Environmental Research (UFZ), and the German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv) have discovered that the network of plants and their pollinators there has changed considerably since the end of the 19th century. As the scientists warn in an article published in Nature Ecology & Evolution, this could lead to plants being pollinated less effectively. This, in turn, would adversely affect their reproduction.

Their service is invaluable. The army of insects and other animals that pollinates the numerous plants of this earth has an essential function. Without these flower visitors, numerous wild plants could reproduce only poorly - or not at all. Ecosystems would thus no longer be able to function in their current form. More than three quarters of the most important crops depend on pollinators in order to be able to produce a high yield and good quality. A loss of pollinators would therefore also lead to economic losses amounting to billions.

Tuesday, December 20, 2022

Diving birds are more prone to extinction, says new study

Diving birds like puffins are highly adapted for their environment, but that means they can't adapt so well to changing conditions.
Photo Credit: Michael Blum

Diving birds like penguins, puffins and cormorants may be more prone to extinction than non-diving birds, according to a new study by the Milner Centre for Evolution at the University of Bath. The authors suggest this is because they are highly specialized and therefore less able to adapt to changing environments than other birds.

The ability to dive is quite rare in birds, with less than a third of the 727 species of water bird using this way of hunting for food.

Evolutionary scientists Joshua Tyler and Dr Jane Younger studied of the evolution of diving in modern waterbirds to investigate how diving impacted: the physical characteristics of the birds (morphology); how the species evolved to increase diversity (rate of speciation); and how prone the species were to extinction.

The study, published in Proceedings of the Royal Society B, found that diving evolved independently 14 times, and that once a group had evolved the ability to dive, subsequent evolution didn’t reverse this trait.

The researchers found that body size amongst the diving birds had evolved differently depending on the type of diving they did.

Monday, December 19, 2022

Daylong wastewater samples yield surprises

Rice University engineers compared wastewater “grabs” to daylong composite samples and found the grab samples were more likely to result in bias in testing for the presence of antibiotic-resistant genes.
 Illustration Credit: Stadler Research Group/Rice University

Testing the contents of a simple sample of wastewater can reveal a lot about what it carries, but fails to tell the whole story, according to Rice University engineers.

Their new study shows that composite samples taken over 24 hours at an urban wastewater plant give a much more accurate representation of the level of antibiotic-resistant genes (ARGs) in the water. According to the Centers for Disease Control and Prevention (CDC), antibiotic resistance is a global health threat responsible for millions of deaths worldwide.

In the process, the researchers discovered that while secondary wastewater treatment significantly reduces the amount of target ARG, chlorine disinfectants often used in later stages of treatment can, in some situations, have a negative impact on water released back into the environment.

The lab of Lauren Stadler at Rice’s George R. Brown School of Engineering reported seeing levels of antibiotic-resistant RNA concentrations 10 times higher in composite samples than what they see in “grabs,” snapshots collected when flow through a wastewater plant is at a minimum.

New study finds logged tropical forests are surprisingly vibrant and need protection

Logged tropical forests are surprisingly vibrant and need protection.
Photo Credit: Zoe G Davies

A new study by researchers at the University of Oxford, finds that logged rainforests are treasure-troves of healthy ecological function and should not be written off for oil palm plantations.

The study examines the flow of ecological energy across old-growth forests, logged forests and oil palm

Surveys mammal and bird species across these landscapes to calculate food energetic pathways: how photosynthetic energy cascades from sunlight to be distributed among organisms

Relative to energy flow in old-growth forests, study finds 2.5 times more total energy flows in logged forests

The study findings question the use of the word “degraded” to describe logged tropical forests

Friday, December 16, 2022

Bird Diversity Increased in Severely Burned Forests of Southern Appalachian Mountains

Forest burned in high-severity wildfire.
Photo Credit: Chris Moorman

A new study found bird diversity increased in North Carolina mountain forest areas severely burned by wildfire in 2016, reinforcing that while wildfire can pose risks to safety and property, it can be beneficial to wildlife. The study results could help forest managers better predict bird responses to wildfire, and manage forests to benefit birds.

“It’s important for us to understand the relationships between animals and wildfire dynamics as the climate changes because predictions show more of these high-severity wildfires across the landscape in the future,” said study co-author Chris Moorman, professor of forestry and environmental resources at North Carolina State University.

Wildfires burned more than 235 square miles of forest in the southern Appalachians in the fall of 2016, following a period of dry conditions and acts of arson. In the study published in the journal Forest Ecology and Management, researchers tracked different levels of burn severity in three forest regions of the Nantahala National Forest in western North Carolina.

A poison helps to understand hydrogen-producing biocatalysts

Thomas Happe researches biocatalysts that can produce hydrogen in an environmentally friendly way.
 Photo Credit: RUB, Marquard

The toxic cyanide molecule attacks the enzymes, but also enables new insights into catalysis.

In nature, certain enzymes, so-called hydrogenases, are able to produce molecular hydrogen (H2) to produce. Special types of these biocatalysts, so-called [FeFe] hydrogenases, are extremely efficient and therefore of interest for bio-based hydrogen production. Although science already knows a lot about how these enzymes work, some details have not yet been fully clarified. The photobiotechnology working group at the Ruhr University Bochum around Dr. Jifu Duan and Prof. Dr. Close Thomas Happe. The researchers showed that external cyanide binds to the [FeFe] hydrogenases and inhibits hydrogen formation. They were able to demonstrate a structural change in the proton transport path that helps to understand the coupling of electron and proton transport. They report in the journal Angewandte Chemie.

Thursday, December 15, 2022

Biodegradable medical gowns may add to greenhouse gas

Photo Credit: National Cancer Institute

The use of disposable plasticized medical gowns – both conventional and biodegradable – has surged since the onset of the COVID-19 pandemic. Landfills now brim with them.

Because the biodegradable version decomposes faster than conventional gowns, popular wisdom held that it offers a greener option by less space use and chronic emissions in landfills.

That wisdom may be wrong.

Biodegradable medical gowns actually introduce harsh greenhouse gas discharge problems, according to new research published Dec. 20 in the Journal of Cleaner Production.

“There’s no magic bullet to this problem,” said Fengqi You, the Roxanne E. and Michael J. Zak Professor in Energy Systems Engineering, in the Smith School of Chemical and Biomolecular Engineering.

“Plasticized conventional medical gowns take many years to break down and the biodegradable gowns degrade much faster, but they produce gas emissions faster like added methane and carbon dioxide than regular ones in a landfill,” said You, who is a senior faculty fellow in the Cornell Atkinson Center for Sustainability. “Maybe the conventional gowns is not so bad.”

Scientists find iron cycling key to permafrost greenhouse gas emissions

Iron content gives a reddish hue to an area of ponded water in the Arctic permafrost. ORNL scientists are exploring the importance of the iron cycle on how greenhouse gases are released from thawing Arctic soils.
Photo Credit: David Graham/ORNL, U.S. Dept. of Energy

The interaction of elemental iron with the vast stores of carbon locked away in Arctic soils is key to how greenhouse gases are emitted during thawing and should be included in models used to predict Earth’s climate, Oak Ridge National Laboratory scientists found.

Researchers set out to explore and model the chemistry going on as the Arctic permafrost thaws in response to global warming. Northern permafrost soils contain an estimated 1,460 billion to 1,600 billion metric tons of organic carbon — about twice as much as in the atmosphere, according to the National Oceanic and Atmospheric Administration.

Chemical processes in the soil control how organic matter decomposes and is stored in soils and whether it converts to carbon dioxide or the more powerful greenhouse gas methane when released into the atmosphere.

Arctic soils are typically organic-rich and often have a high iron content, frequently visible as rusty deposits in flooded soils in the region, said ORNL modeler and principal investigator Benjamin Sulman. But current Earth system models do not take iron cycling into account when predicting the climate-warming potential of thawing permafrost.

Early green, early brown – climate change leads to earlier senescence in alpine plants

Alpine plants that start to grow earlier also start to age earlier. As is the case with the alpine vegetation in these containers, which were exposed to summer weather several months before the snow melted photograph taken in July
Photo Credit: P. Möhl

Global warming is leading to longer growing seasons worldwide, with many plants growing earlier in spring and continuing longer in autumn thanks to warmer temperatures—so is the general opinion. Now, however, plant ecologists at the University of Basel have been able to show that this is not the case for the most common type of alpine grassland in the European Alps, where an earlier start leads to earlier aging and leaves the grassland brown for months.

Spring 2022 was extremely warm, giving many plants an early start to the growing season. And the Swiss Alps were no exception, with the snow cover melting early and the underlying vegetation being quickly roused into growth. Researchers at the Department of Environmental Sciences at the University of Basel have investigated how such an early start affects the plants’ further development.

For their study, they removed intact blocks of alpine grassland and placed them in walk-in climate chambers at Basel’s Botanical Institute. Here, they left the vegetation to overwinter artificially in cold darkness, and then switched some of the blocks to summer conditions in February. A second group was left in the cold dark until April, before summer was introduced here as well. The researchers compared the growth and aging of these plants with their neighbors growing naturally at an elevation of 2,500 meters, which did not emerge from the snow until late June.

Wednesday, December 14, 2022

Paris Agreement temperature targets may worsen climate injustice for many island states

A comparison of global greenhouse gas emissions from 1990 – 2018 shows the low emissions contribution of AOSIS nations (blue) and increasing levels of total global emissions (red).
Illustration Credit: Sadai et al., 10.1029/2022EF002940

While the world focuses on limiting the rise in global temperature to 1.5 or 2 degrees Celsius over the preindustrial average, increasing meltwater from ice sheets presents an existential threat to the viability of island and coastal nations throughout the world. Now, research from the University of Massachusetts Amherst, recently published in the journal Earth’s Future, shows that even the most optimistic temperature targets can lead to catastrophic sea-level rise, which has already begun and will affect low-lying nations for generations to come.

While rising temperatures are having many deleterious effects on global ecosystems, economies and human wellbeing, an interdisciplinary team of researchers at the University of Massachusetts emphasize that temperature alone is not a sufficient basis for climate policy. 

Tuesday, December 13, 2022

Not everyone aware sustainable diets are about helping the planet

Sustainable diets
Photo Credit: yilmazfatih

A new study has found that young Brits would be willing to change to a more sustainable diet, but a lack of understanding about what that actually means is preventing many from doing so.

Many people are also uncertain about what changes they should make.

Sustainable diets are defined by the UN as “diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations.”

Previous research has suggested that 20-30% of environmental impacts in Europe and the UK originate from our diets, including impacts from food production, processing and retail. It is also now widely accepted that the consumption of meat and animal products typically has a higher environmental impact than plant-based foods.

“When thinking about how to live more sustainably, people seem to understand that this can mean taking fewer flights, using the car less, recycling more, but it seems that not everyone is aware of the difference that changing their diet can make as well,” explained Katherine Appleton, Professor of Psychology at Bournemouth University, who led the study.

Methane from manholes and historic landfills: significant sources of gas go unrecognized

Montreal’s municipal greenhouse gas inventory presents an incomplete picture of methane emissions
Photo Credit: Mohammad Rezaie

Cities are responsible for almost 1/5th of the global methane emissions caused by human activities. But most cities don’t capture information about the full range of sources of this powerful greenhouse gas. In 2020, a team led by McGill University, measured methane emissions from various sources across the city of Montreal. The researchers found that two of the four most important sources of methane emissions in the city (historic landfills and manholes) are not included in the city’s municipal greenhouse gas inventories, making it difficult to tackle the problem fully, or reach the city’s goal of being carbon neutral by 2050.

The study provides the first set of direct measurements of methane emissions in Montreal and in the province of Quebec.

The study provides detailed and specific measurements of methane emissions by source – such as the type of manhole or the type of natural gas infrastructure. The results, which highlight the importance of gathering information about the specific sources of methane emissions to set in place mitigation strategies that are adapted to each specific situation should be of interest not only to researchers across Canada and around the world but also to policy makers.

Pollution cleanup method destroys toxic “forever chemicals”

Ultraviolet light used for water treatment 
Photo Credit: UCR/Liu Lab

An insidious category of carcinogenic pollutants known as “forever chemicals” may not be so permanent after all.

University of California, Riverside, chemical engineering and environmental scientists recently published new methods to chemically break up these harmful substances found in drinking water into smaller compounds that are essentially harmless.

The patent-pending process infuses contaminated water with hydrogen, then blasts the water with high-energy, short-wavelength ultraviolet light. The hydrogen polarizes water molecules to make them more reactive, while the light catalyzes chemical reactions that destroy the pollutants, known as PFAS or poly- and per-fluoroalkyl substances.

This one-two punch breaks the strong fluorine-to-carbon chemicals bonds that make these pollutants so persistent and accumulative in the environment. In fact, the molecular destruction of PFAS increased from 10% to nearly 100% when compared to other ultraviolet water-treatment methods, while no other undesirable byproducts or impurities are generated, the UCR scientists reported in a paper recently published in the Journal of Hazardous Materials Letters.

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