80% of Earth's Rivers Are Quickly Losing Oxygen, Study Reveals

20 May 2026, By J. Cockerill

https://www.sciencealert.com/80-of-earths-rivers-are-quickly-losing-oxygen-study-reveals

The River Ganges is one of many waterways across Earth experiencing accelerating deoxygenation. 

(artfotoss/iStock/Getty Images Plus)

Oxygen levels have decreased in almost 80 percent of rivers worldwide, and they're going to continue losing this precious resource unless we make some serious changes.

Satellite and climate data collected between 1985 and 2023 reveal that over 16,000 rivers across the world have been losing their dissolved oxygen.

On average, these rivers have been losing 0.045 milligrams of oxygen per liter each decade.

Without enough dissolved oxygen essential to sustain life underwater, rivers – and the communities that rely on their water and resources – are under serious threat.

These findings come from a team at the Chinese Academy of Sciences, led by environmental scientist Qi Guan.

The team compiled data from 3.4 million satellite images across the past four decades to detect patterns in the dissolved oxygen of rivers across the world and forecast their futures under different climate scenarios.

By the end of the century, assuming carbon dioxide emissions continue to rise at similar rates (as opposed to some of the worst-case scenarios), rivers across most of South America, India, the Arctic, and the Eastern United States are expected to lose around 10 percent of their dissolved oxygen.

The most severe shifts so far have occurred in tropical rivers, such as the Ganges in India and the Amazon River in South America. The Ganges River in particular is losing oxygen 20 times faster than the global average.

Scientists didn't see this coming.

Previously, they assumed that high-latitude rivers would experience the worst deoxygenation because these regions are climate change hotspots.

But tropical rivers had a disadvantage from the start: Since their waters were already warmer, they already had lower levels of dissolved oxygen. This means they're already closer to reaching hypoxia (insufficient oxygen to sustain most life).

Aerial view of the low water level of the Amazon River in Colombia in 2024.

 (Luis Acosta/AFP via Getty Images)



Guan and team found many factors are contributing to global river deoxygenation, but none more so than climate change.

Climate change driven by human activities is reducing oxygen solubility (the ability of a body of water to hold dissolved oxygen). According to the new study, oxygen solubility accounts for about 63 percent of global river deoxygenation.

Water temperature is most likely driving this change in oxygen solubility. Warmer waters hold less dissolved oxygen because the oxygen and water molecules are receiving more energy in the form of heat.

Dissolved oxygen is very different from the oxygen atoms that pair with a hydrogen to form water. Dissolved oxygen is what aquatic life needs to 'breathe': that goes for animals, plants, plankton, bacteria, and anything else living underwater.

But the bonds that keep oxygen gas dissolved in water are relatively weak. Just a slight shift in temperature is enough to rip them apart, allowing the oxygen to escape.

https://www.youtube.com/watch?v=oVW5LAzd7Ec&t=1s

Aquatic species vary widely in terms of how much dissolved oxygen they need to survive. Still, a change of 0.1 milligrams per liter of river water – which is roughly how much has been lost, on average, across the past four decades – is enough to cause some serious shifts in river ecosystems.

Aquatic life can add to the dissolved oxygen levels by photosynthesizing, which is why underwater plants keep waterways healthy. Oxygen from the atmosphere can also become dissolved in water via physical forces, such as burbling river rapids or the aerators used in human-made ponds.

That's why, in many of the rivers included in this study, dams in shallow waterways and heatwaves have contributed to waning levels of dissolved oxygen. Reduced water flow means less oxygen is folded into the water from the air; heatwaves essentially squeeze the oxygen out of rivers.

Water composition also has a major impact on the levels of dissolved oxygen a river can hold. Human activities are changing water composition at both ends, by reducing the amount of water in rivers, and adding to the water's load of solutes, such as salt, nutrients, and organic matter (which further reduces oxygen solubility).

Since aquatic life relies on dissolved oxygen to survive, even a small drop in levels can quickly lead to mass die-off events.

Once that happens, a river full of dead fish and algae quickly uses up any remaining dissolved oxygen as bacteria get to work on breaking down the organic matter left behind.

With increasing rates of river deoxygenation across the world, dead zones like this may become more common.

"Deoxygenation is a very slow process. If we have a long period, the negative impact will attack the river ecosystems," Guan told Seth Borenstein at Associated Press.

"The low level of oxygen can cause a series of ecological crises such as biodiversity decline [and] water quality degradation."

Those scenarios are far more likely if rivers lose an additional four or five percent of their dissolved oxygen: the same amount that they're expected to lose within the next seven decades, unless humanity takes urgent action to prevent further fossil fuel emissions.

"Systematically understanding these changes is crucial for enhancing the resilience of fluvial ecosystems to sustained deoxygenation risks through targeted measures and strategies, and helps to achieve sustainable management in global rivers," Guan and team conclude.

The Life of Earth

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Scientists Discover Hidden Sleep Switch That Boosts Brainpower, Builds Muscle, and Burns Fat

By U. of California - Berkeley, May 20, 2026

https://scitechdaily.com/scientists-discover-hidden-sleep-switch-that-boosts-brainpower-builds-muscle-and-burns-fat/

A new study reveals how the brain carefully balances sleep, growth hormone release, and wakefulness — a connection that may influence everything from metabolism to cognition.

 Credit: Shutterstock

Scientists have uncovered a previously unknown brain feedback system that links deep sleep, growth hormone release, and wakefulness.

Most people think of sleep as a time when the body simply rests. In reality, the brain is carrying out a complex series of processes that regulate everything from metabolism and tissue repair to memory and hormone production. One of the most important of these hormones is growth hormone, which helps build muscle and bone, regulate fat metabolism, and support overall health.

Scientists have known for decades that growth hormone is closely tied to deep sleep, especially the early stages of non-REM sleep. Even a lack of sleep for a single night can reduce hormone levels. But exactly how the brain controls this process has remained poorly understood.
Researchers Map the Brain Circuit Behind Growth Hormone Release

Now, researchers at the University of California, Berkeley, have identified the brain circuits responsible for controlling growth hormone release during sleep. Their study, published in Cell, also uncovered a previously unknown feedback system in the brain that helps keep hormone levels balanced while regulating wakefulness.

The findings provide a clearer picture of how sleep and hormone regulation are connected. Researchers say the discovery could eventually contribute to new treatments for sleep disorders linked to metabolic diseases such as diabetes, as well as neurodegenerative conditions including Parkinson’s and Alzheimer’s disease.

During sleep, the brain produces growth hormone to help build muscle and bone and reduce fat. UC Berkeley research in mice reveals the brain circuits that regulate growth hormone release, along with a brainstem feedback mechanism that promotes wakefulness after a good night’s sleep. 

Credit: Yang Dan lab/UC Berkeley



“People know that growth hormone release is tightly related to sleep, but only through drawing blood and checking growth hormone levels during sleep,” said study first author Xinlu Ding, a postdoctoral fellow in UC Berkeley’s Department of Neuroscience and the Helen Wills Neuroscience Institute. “We’re actually directly recording neural activity in mice to see what’s going on. We are providing a basic circuit to work on in the future to develop different treatments.”

Because growth hormone also affects glucose and fat metabolism, poor sleep may increase the risk of obesity, diabetes, and cardiovascular disease.

Key Brain Regions Involved in Sleep and Hormone Regulation

The neurons responsible for regulating growth hormone release during the sleep-wake cycle are located deep within the hypothalamus, a brain region shared across mammals. These include growth hormone releasing hormone (GHRH) neurons and two types of somatostatin neurons.

After growth hormone is released, it increases activity in the locus coeruleus, a brainstem region involved in attention, arousal, cognition, and responses to new experiences. Problems affecting the locus coeruleus have been associated with several psychiatric and neurological disorders.

“Understanding the neural circuit for growth hormone release could eventually point toward new hormonal therapies to improve sleep quality or restore normal growth hormone balance,” said Daniel Silverman, a UC Berkeley postdoctoral fellow and study co-author. “There are some experimental gene therapies where you target a specific cell type. This circuit could be a novel handle to try to dial back the excitability of the locus coeruleus, which hasn’t been talked about before.”

Working in the lab of Yang Dan, a professor of neuroscience and molecular and cell biology, the researchers implanted electrodes into mouse brains and monitored neural activity while stimulating hypothalamic neurons with light. Because mice sleep in short bursts lasting only a few minutes throughout the day and night, they provided researchers with repeated opportunities to examine hormone activity during sleep cycles.

Distinct Hormone Activity During REM and Non-REM Sleep

Using advanced neural circuit tracing techniques, the researchers found that the two peptide hormones involved in growth hormone release behave differently depending on the stage of sleep. GHRH stimulates growth hormone release, while somatostatin suppresses it.

During REM sleep, levels of both hormones rise sharply, increasing growth hormone release. During non-REM sleep, somatostatin levels drop while GHRH levels rise more moderately, which also boosts growth hormone production.

The researchers also found evidence of a feedback system involving the locus coeruleus. As growth hormone gradually builds during sleep, it stimulates this brain region and encourages wakefulness. However, when the locus coeruleus becomes overly active, it can unexpectedly increase sleepiness, according to earlier work by Silverman.

“This suggests that sleep and growth hormone form a tightly balanced system: Too little sleep reduces growth hormone release, and too much growth hormone can in turn push the brain toward wakefulness,” Silverman said. “Sleep drives growth hormone release, and growth hormone feeds back to regulate wakefulness, and this balance is essential for growth, repair, and metabolic health.”

Because the locus coeruleus also helps regulate overall brain arousal during wakefulness, researchers believe maintaining the right balance in this system could influence attention and cognitive function as well.

“Growth hormone not only helps you build your muscle and bones and reduce your fat tissue, but may also have cognitive benefits, promoting your overall arousal level when you wake up,” Ding said.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Turn Wool Into Bone-Healing Material in Medical Breakthrough

By King's College London, May 20, 2026

https://scitechdaily.com/scientists-turn-wool-into-bone-healing-material-in-medical-breakthrough/

A protein extracted from wool has shown surprising potential for guiding bone regeneration in living systems.

 Credit: Shutterstock

Wool-derived keratin membranes helped regenerate organized, stable bone tissue and may offer a promising alternative to collagen in regenerative medicine.

A new study found that keratin, a structural protein taken from wool, can support bone regeneration in living animals. The material produced bone tissue that more closely matched healthy natural bone than collagen, which is currently considered the standard material for these treatments.

Researchers at King’s College London tested the wool-derived keratin in animal models and discovered it could guide new bone growth across damaged areas. The findings suggest the material could become a promising alternative for regenerative medicine and dental procedures.

“We are really excited to show for the first time how a wool-based material has been successfully tested in a living animal to repair bones,” said Dr. Sherif Elsharkawy at King’s Faculty of Dentistry, Oral & Craniofacial Sciences.

The researchers also highlighted the sustainability benefits of the material. Wool is naturally sourced and is often discarded as waste by the farming industry, making keratin a renewable and scalable option for medical applications.

Collagen’s Longstanding Role in Bone Repair

For many years, collagen has been widely used as a scaffold in regenerative medicine and dentistry. It works as a protective barrier that keeps soft tissue from disrupting healing while allowing bone to regrow in damaged areas.

Despite its widespread use, collagen has several drawbacks. The material is relatively weak and can degrade too quickly, especially in situations where healing bone must withstand pressure or support weight. Extracting collagen can also be expensive and technically challenging.

Dr. Sherif Elsharkawy holding a human skull. 

Credit: King’s College London



“From a research perspective, this is a major milestone. It positions keratin as a potential new class of regenerative biomaterial that could challenge the long-standing reliance on collagen,” said Elsharkawy.

To investigate alternatives, the researchers created membranes from keratin extracted from wool. The material was chemically treated to produce stable and durable scaffolds designed to support bone regeneration.

Keratin Membranes Show Early Promise in Lab Tests

The team first tested the keratin membranes on human bone cells in the lab. The cells grew successfully and showed strong signs of healthy bone development.

The researchers then implanted the membranes into rats with skull defects large enough that they would not heal on their own. Over the following weeks, the team observed how the keratin scaffolds supported bone growth across the damaged sections.

While collagen membranes generated a greater amount of bone overall, the keratin scaffolds produced bone that was more organized and structurally stable. The fibers were also better aligned and more closely resembled the structure of healthy natural bone.

Stable Healing Brings Keratin Closer to Human Use

The keratin membranes also blended well with surrounding tissue and stayed stable throughout the healing process. Researchers said these qualities are important for potential real-world medical use.

“We’ve effectively demonstrated the technology in an animal model, which makes this much more than an early materials concept. It shows that keratin can support bone regeneration in a living biological system, bringing the technology significantly closer to use in real patients,” said Elsharkawy.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Keep Finding Major Discoveries Lurking in Museum Backrooms

18 May 2026, By M. Starr

https://www.sciencealert.com/scientists-keep-finding-major-discoveries-lurking-in-museum-backrooms

(Hill Street Studios/DigitalVision/Getty Images)

Museums are among the most expansive resources humans have created.

For most of us, these edifices display rich collections of treasures and knowledge that transport us through time.

For scientists, they're a treasure of a different kind.

In vast warehouses inaccessible to the public, many museums store hoards of more artifacts that rarely see the light of day, and were accumulated faster than humans can study them.

That's why so many discoveries are made not in the field, but in museum backrooms, among wonders half-forgotten for decades.

To celebrate International Museum Day, here are some of our favorite recent discoveries that only emerged when the right person came along to make them.

The oldest known whale bone tools

In a bid to make sense of the hundreds of prehistoric artifacts squirreled away in museums across Europe, a team of archaeologists sat down and compiled a comprehensive catalog using a suite of techniques to date the artifacts and find out what they were made of.

Their results yielded around 150 tools made from whale bone, arising from the Magdalenian culture that occupied coastal and inland regions of western Europe some 19,000 to 14,000 years ago – the earliest known of their kind.

This whale bone point was found in the Duruthy rock shelter in France. 

(Alexandre Lefebvre)



This discovery reveals interesting new details about the whales that once inhabited the Bay of Biscay and how humans interacted with their remains.

"Even old collections, excavated more than one century ago with field methods now outdated, and stored in museums for a long time, can bring new scientific information when approached with the right analytical tools," University of Toulouse-Jean Jaurès archaeologist Jean-Marc Pétillon told ScienceAlert.

Metal from the sky

The Treasure of Villena – discovered more than 60 years ago in 1963 in what is now Alicante in Spain – wasn't exactly moldering away in a storeroom.

As one of the most important examples of ancient goldsmithing in Europe, forged more than 3,000 years ago during the Iberian Bronze Age, it was revered but still somewhat overlooked.

The iron-and-gold hemisphere, which has a maximum diameter of 4.5 centimeters (1.77 inches). 

(Villena Museum)

Then, in 2024, it yielded a surprise. Scientists analyzed two oddities in the collection, a bracelet and a hemisphere made from dull brown material – and found they were made, not from earthly metal, but with iron from meteorites that fell from the sky – in a time before the advent of iron smelting technology.

"The available data suggest that the cap and bracelet from the Villena Treasure are currently the first two pieces attributable to meteoritic iron in the Iberian Peninsula," the researchers wrote.

https://www.youtube.com/watch?v=M4kUXxcS9Io&t=3s

Not a mammoth

It made sense that large bones found inland in the heart of Alaska were identified as belonging to a woolly mammoth and not examined for 70 years.

However, when researchers finally studied the bones as part of a program launched in 2022, radiocarbon dating revealed that the animal that left them lived long after mammoths had gone extinct.

Images of some of the bones. 

(University of Alaska Museum of the North)



Comparison of the bones' mitochondrial DNA with modern species revealed an even bigger surprise: It was not one animal, but two, and they were both whales.

"How did the remains of two whales that are more than 1,000 years old come to be found in interior Alaska, more than 400 km (250 miles) from the nearest coastline?" the researchers queried.

It's a question that remains to be answered.

Darwin meets lasers

Sometimes it's not the specimen, but the method of studying it that reveals new information.

Some of the specimens collected by Charles Darwin in the 19th century. (Dr Sara Mosca, STFC Central Laser Facility)



Some 200 years ago, legendary naturalist Charles Darwin collected hundreds of specimens, preserved in sealed jars. The problem is that many different fluids were used for specimen preservation, and it was unknown which of them Darwin had used.

We can't just unseal the jars and take a peek – that could destroy the delicate remains – so, in a paper published in January 2026, scientists detailed the way they used laser light to identify the methods Darwin had used.

Interestingly, he had different fluids for different kinds of animals – and this information, the scientists said, will help them continue to care for these precious specimens for future generations.

A dinosaur herd written in opal

Australia is one of the only places in the world with the right conditions for fossil opalization – the replacement of bone with shimmering rainbow opal.

An opalized Fostoria dhimbangunmal bone. 

(Robert A Smith/Australian Opal Center)



Many of these specimens are stunningly beautiful, but with opal being so valuable, they often have a checkered history. Some are squirreled away in private collections; others get traded; and some go unstudied for years.

A collection of opalized fossils first discovered in 1984 was finally examined by paleontologists decades later, after it was recovered and donated in 2015.

As described in a 2019 paper, the jumble of bones turned out to be the remains of at least four separate animals, all belonging to a previously unknown dinosaur species.

The species was named Fostoria dhimbangunmal. It roamed the eastern flank of Australia during the mid-Cretaceous, in herds large enough that this group stayed together even after death, turning into beautiful gemstones together.

Three-eyed brains

The Burgess Shale truly is a fossil cornucopia like no other. This spectacular, 508-million-year-old fossil bed is so rich that, often, paleontologists can only collect them and put them aside to create an archive that is slowly being worked through.

A reconstruction of Stanleycaris hirpex hovering above its fossil. 

(Sabrina Cappelli © Royal Ontario Museum)



One species, Stanleycaris hirpex, is a strange three-eyed animal known as a radiodont, related to modern arthropods.

Hundreds of Stanleycaris fossils have been collected, but it wasn't until a 2022 paper – two decades after they were discovered – that scientists revealed just how exciting these tiny animals really are.

In 84 specimens from a collection of 268 Stanleycaris fossils, the brain was preserved in exquisite detail – a discovery that shed new light on the evolution of arthropod brains.

"We can even make out fine details such as visual processing centers serving the large eyes and traces of nerves entering the appendages," said evolutionary biologist Joseph Moysiuk of the University of Toronto.

The world has more marvels than we currently have time to examine.

While museums offer a place of learning for many of us, for scientists, they provide a place to keep irreplaceable treasures safe until the right researcher arrives to unravel the secrets they hold.

The Life of Earth

https://chuckincardinal.blogspot.com/

Fog Is Teeming With Life, And It May Be Doing Us a Surprising Favor

19 May 2026, By M. Irving

https://www.sciencealert.com/fog-is-teeming-with-life-and-it-may-be-doing-us-a-surprising-favor

(Daniel Garrido/Moment/Getty Images)

There's something living in the fog – but you'll be glad to know that it's mostly friendly.

Researchers at Arizona State University and Susquehanna University have found that bacteria are living and growing inside droplets of water in fog, at concentrations comparable to seawater.

While it does mean fog isn't as sterile as it may seem, those microbes are at least earning their keep: They've been found to break down pollutants in the air.

From ground-level sneezes to the highest of clouds, it's long been known that bacteria are floating around in the atmosphere in decent numbers.

But it's less clear whether these microbes are actively living in these airborne environments, or are just passing through on their way to other habitats.

Fittingly, fog is even more mysterious.

"There's very limited knowledge about what kinds of bacteria are present in fogs, which are like clouds at the ground level," says Thi Thuong Thuong Cao, a microbiologist at Arizona State University (ASU).

The research team's experimental setup for capturing fog samples. 

(Thi Thuong Thuong Cao)



To investigate, the researchers on the new study collected air samples before, during, and after fog events on 32 different occasions over a two-year period.

To control for wind blowing everything around and messing with readings, the team specifically examined radiation fog, a type that forms in calm, still air overnight.

And sure enough, a sizable microbiome was detected in that chilly morning air.

Bacteria were present in less than one percent of fog droplets. That doesn't sound like much, but it averages to around 1 million 16S rRNA gene copies – a common marker for estimating bacterial abundance – per milliliter of water.

Concentration of bacterial 16S rRNA gene copies in air samples collected before and after six fog events in 2022. 

(Cao et al., mBio, 2026)



"When you take all of the droplets together, the concentration of bacteria is the same as in the ocean," says Ferran Garcia-Pichel, a microbiologist at ASU.

To answer the question of which bacteria are present, the team conducted genetic analyses. This revealed that those in the Methylobacterium genus dominated the picture.

And they didn't seem to be inert, either.

"If they are growing, then the droplets are a habitat. That's a mindset change," says Ferran Garcia-Pichel.

In a subsample of six fog events, the team found that even after the fog cleared, the air contained around 45 percent more bacteria than at the same location before the fog settled in.

That suggests that something about the foggy atmosphere is actively culturing the bacteria.

"We observed them under the microscope to see that yes, the bacteria are getting bigger and they're dividing, so there is growth," says Cao.

Methylobacteria are known to eat volatile carbon compounds such as formaldehyde, so the team suspected this might be the source of their growth.

To check, the researchers incubated samples of fog water and measured how levels of these compounds changed over time.

Unsurprisingly, these levels dropped – but what was surprising was the speed with which the compounds were consumed.

A foggy Pennsylvania field has a secret: Its droplets are home to 'pollutant-eating' bacteria. 

(Thi Thuong Thuong Cao)

"Existing formaldehyde at the start of the incubation was swiftly consumed to undetectable levels," the researchers write, "roughly 200-fold faster than rates measured elsewhere in cloud water."

That's much too fast to purely be a source of food, the team says. Instead, it's probably for "detoxification purposes" as well, since high levels of formaldehyde can be toxic to the bacteria.

The good news is that these compounds are pollutants for us too, meaning this aerial microbiome may have a cleansing effect. Exactly how beneficial this is in the real world will require more research, though.

"The sky's the limit," Garcia-Pichel says.

The Life of Earth

https://chuckincardinal.blogspot.com/

The Evolution of Cannabis: 28 Million Years of Secrets Hidden From You

Mysteries of the World, Apr 26, 2026

https://www.youtube.com/watch?v=sxKgoaTBh00

(Use the link to watch on ytube for english, Chuck)

About 28 million years ago, a small plant emerged on the slopes of the ancient Tibetan Plateau that was destined to change the course of human history.

 Cannabis is one of the most mysterious and controversial plants on Earth, and its evolutionary history is far more astonishing than you might imagine.

 In this video, we'll explore the complete evolution of cannabis: from its origins in the high steppes of Asia to its emergence as a companion plant 12,000 years ago—long before wheat, corn, and potatoes. You'll learn how plate tectonics literally created the conditions for this plant's emergence, why cannabis and hops (the basis of beer brewing) turned out to be genetically related, and how a groundbreaking 2021 study involving whole-genome sequencing has revolutionized scientists' understanding of marijuana's origins. 

But the most intriguing question is: why is cannabis capable of altering our consciousness? The answer lies in the endocannabinoid system, an ancient biological network that has existed in animals for 600 million years—we even share it with sea urchins.

A plant that evolved to protect itself from UV rays and herbivores accidentally created a molecule that perfectly fits receptors in our brain. We'll talk about the Scythians and Herodotus, ancient rituals in the Chinese mountains, the secret breeding of cannabis in 20th-century basements, and how humans turned the plant's defense mechanism into a source of pleasure. 

This is a story about how geology shapes biology, and biology shapes culture. 

go to above link for english version

The Life of Earth

https://chuckincardinal.blogspot.com/

Common Cleaning Chemical Could Triple Your Risk of a Dangerous Liver Disease

By SciTechDaily.com, May 18, 2026

https://scitechdaily.com/common-cleaning-chemical-could-triple-your-risk-of-a-dangerous-liver-disease/

Liver fibrosis is a condition in which excessive scar tissue builds up in the liver after repeated injury or inflammation. Over time, this scarring can disrupt normal liver function and may progress to cirrhosis, liver failure, or liver cancer if left untreated. 

Credit: Stock

Scientists are uncovering a possible connection between everyday chemical exposure and serious liver damage.

Most people associate liver disease with heavy drinking or obesity. But researchers are increasingly uncovering another possible threat hiding in everyday life: industrial chemicals that can linger in the air we breathe, the water we drink, and even the clothes we pick up from the dry cleaner.

A new study published in Liver International points to tetrachloroethylene (PCE), a chemical widely used in dry cleaning and manufacturing, as a potential contributor to serious liver damage. Scientists at Keck Medicine of USC found that people with detectable levels of PCE in their blood were more than three times as likely to have significant liver fibrosis, a dangerous buildup of scar tissue that can eventually lead to liver failure, liver cancer, or death.

Tetrachloroethylene (PCE), widely used in dry cleaning and manufacturing, has been linked to increased odds of liver scarring. Credit: Stock



The findings add to growing concerns about how environmental pollutants may quietly influence chronic diseases that are often blamed on lifestyle factors alone. Researchers say the study is the first to directly connect PCE exposure in the general U.S. population with measurable liver scarring.

“This study, the first to examine the association between PCE levels in humans and significant liver fibrosis, underscores the underreported role environmental factors may play in liver health,” said Brian P. Lee, MD, MAS, a hepatologist and liver transplant specialist with Keck Medicine and lead author of the study. “The findings suggest that exposure to PCE may be the reason why one person develops liver disease while someone with the exact same health and demographic profile does not.”

Dr. Brian P. Lee, MD, MAS, is a hepatologist and liver transplant specialist with Keck Medicine of USC and principal investigator of the study. Credit: Dr. Brian P. Lee, MD, MAS



A Chemical Found Far Beyond Dry Cleaning

PCE, also called perchloroethylene, is a colorless volatile organic compound used to dissolve grease and remove stains. Although it is best known as a dry-cleaning solvent, it has also been used in metal degreasing, industrial manufacturing, adhesives, spot removers, and some household cleaning products.

Exposure often happens through inhalation. Clothes cleaned with PCE can slowly release the chemical into indoor air for days after pickup. In some communities, the chemical has also contaminated groundwater and drinking water after industrial spills or improper disposal seeped into the soil. Because PCE evaporates easily, it can spread through buildings and surrounding neighborhoods as a vapor.

Scientists have studied PCE for decades because of its toxic effects. The International Agency for Research on Cancer classifies it as a probable carcinogen, and previous research has linked it to bladder cancer, multiple myeloma, non-Hodgkin lymphoma, and liver cancer. Animal studies have also shown that the chemical can trigger inflammation, oxidative stress, and cellular damage in the liver.

In response to mounting evidence, the U.S. Environmental Protection Agency recently began a 10-year phaseout of PCE in dry cleaning operations and imposed new restrictions on several industrial uses. Still, the compound remains present in some workplaces, consumer products, and older contaminated sites.

Tracking Liver Damage in the U.S. Population

To investigate whether PCE exposure might be affecting liver health on a national scale, researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES), a long-running federal program designed to reflect the health of the U.S. population.

The study included 1,614 adults age 20 and older between 2017 and 2020. Blood testing showed that about 7.4% of participants had detectable levels of PCE. Concentrations ranged from 0.034 to 57.5 nanograms per milliliter.

After adjusting for age, sex, race, ethnicity, education, and other health factors, the connection between PCE and liver fibrosis remained strong. People with detectable PCE exposure had more than triple the odds of significant liver fibrosis compared with those who had no detectable exposure.

PCE can contaminate air and groundwater, creating potential exposure far beyond dry-cleaning shops.

 Credit: Stock



The study also found a striking dose-response relationship: for every one nanogram per milliliter increase in blood PCE concentration (one nanogram is one-billionth of a gram), the odds of significant liver fibrosis increased more than fivefold, with detectable PCE exposure corresponding to an absolute increase in fibrosis risk of nearly 28%.

Importantly, the association appeared independent of traditional liver disease risks such as alcohol use or obesity-related fatty liver disease. That finding raises the possibility that environmental toxins may help explain why some people develop liver disease despite having few conventional risk factors.

“Patients will ask, how can I have liver disease if I don’t drink and I don’t have any of the health conditions typically associated with liver disease, and the answer may be PCE exposure,” said Lee.
Who Faces the Highest Exposure?

The study found that people from higher-income households were more likely to have detectable PCE levels, possibly because they use dry-cleaning services more frequently. However, researchers noted that workers in dry-cleaning facilities and industrial settings may face even greater exposure because of repeated, direct contact with the chemical over long periods.

The authors also performed a “negative control” analysis using a different biomarker linked to mixed VOC exposure. That analysis suggested the liver fibrosis signal was specifically tied to PCE rather than to volatile chemicals in general, strengthening confidence in the findings.
A Growing Focus on Environmental Liver Disease

Liver disease is becoming more common worldwide, and researchers are increasingly exploring how pollution and chemical exposure may contribute alongside diet and alcohol. Unlike smoking or obesity, environmental exposures are often invisible and difficult for individuals to control. Some chemicals can accumulate slowly over years before symptoms appear.

Lee believes the new findings should encourage more research into how environmental toxins affect the liver and whether earlier screening could help identify damage before it becomes irreversible.

“No doubt there are other toxins in our environment besides PCE that are dangerous to the liver,” he said.

He added that recognizing these hidden risk factors could eventually improve patient outcomes.

“We hope our research will help both the public and physicians understand the connection between PCE exposure and significant liver fibrosis,” Lee said. “If more people with PCE exposure are screened for liver fibrosis, the disease can be caught earlier and patients may have a better chance of recovering their liver function.”

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Discover “Good” Gut Microbes That Could Protect Against Autism and ADHD

By Cell Press, May 17, 2026

https://scitechdaily.com/scientists-discover-good-gut-microbes-that-could-protect-against-autism-and-adhd/

A new study suggests that the gut microbiome and epigenetic “switches” that regulate genes may work together from birth to shape early brain development. 

Credit: Stock

A study found that early-life epigenetic changes and gut microbiome development are closely linked and may shape the risk of ASD and ADHD. Some gut bacteria appeared to offer protective effects against these conditions.

From the moment a baby is born, trillions of microbes begin colonizing the gut while molecular “switches” in the body help control which genes are active.

Now, researchers have found that these two systems, the gut microbiome and epigenetics, may work together in ways that influence early brain development and could shape the risk of neurodevelopmental conditions later in childhood.

The study, published in the journal Cell Press Blue, showed that epigenetic changes present at birth can affect how an infant’s gut microbiome develops during the first year of life. The researchers also identified specific epigenetic patterns and gut microbes linked to signs of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) at age three. Some microbes even appeared to play a protective role, potentially reducing the effects associated with certain epigenetic risk patterns.

“Certain bacteria seem to offer protection, which is exciting because it suggests there could be ways to support a child’s development through diet or probiotics in the future,” says senior author and gastroenterologist Francis Ka Leung Chan of The Chinese University of Hong Kong.

Early childhood is a critical period for both brain development and immune system maturation. While previous studies have shown that epigenetic changes and the infant gut microbiome can each influence long-term health, far less is known about how the two systems interact during the earliest stages of life.

Early-Life Epigenome and Microbiome Interaction

“We wanted to see how the epigenome and microbiome interact in early life and if their interaction could influence a child’s risk of developing neurodevelopmental conditions like ASD and ADHD,” says co-senior author and public health researcher Hein Min Tun of The Chinese University of Hong Kong. “We discovered a kind of conversation happening: a baby’s epigenetic setting at birth can influence their risk for neurodevelopmental disorders, but the presence of certain ‘good’ bacteria in their gut can step in and modify the risk.”

The researchers analyzed DNA methylation patterns, a form of epigenetic change, using umbilical cord blood samples from 571 infants. They combined these findings with gut microbiome data collected from 969 infants at 2, 6, and 12 months of age, as well as samples from the parents during the third trimester of pregnancy.

When the children reached 36 months of age, the team used behavioral questionnaires to evaluate neurodevelopment and explore possible connections between the microbiome, epigenome, and early signs of ASD and ADHD.

The results showed that an infant’s epigenome at birth was linked to factors such as delivery method, gestation length, maternal allergies, and having older siblings. However, it was not influenced by the parents’ gut microbiomes. In contrast, microbiome development was associated with delivery method, antibiotic exposure, breastfeeding, and older siblings. Babies delivered by Cesarean section showed different DNA methylation patterns in genes involved in immune function and brain development.
DNA Methylation Linked to Gut Microbiome Diversity

The researchers also found that epigenetic patterns present at birth affected how the microbiome developed during the first year of life. Infants with higher DNA methylation levels in immune genes related to pathogen recognition tended to have less diverse gut microbiomes by 12 months of age.

The behavioral assessments further showed that signs of ASD and ADHD in 3-year-old children were connected to specific epigenetic markers and certain gut microbes.

Some microbial species appeared to reduce these effects. Infants with epigenetic patterns linked to ASD or ADHD were less likely to show signs of the conditions if they acquired Lachnospira pectinoschiza and Parabacteroides distasonis, respectively, during their first year.

Probiotics and Early Interventions for Neurodevelopment

“The foundations for brain health are laid very early, even before birth,” says Tun. “However, we don’t want people to think this means a child’s developmental path is fixed at birth. These are complex conditions with many causes, and we’ve only uncovered a small piece of a very large puzzle.”

The researchers are continuing to track the children involved in the study to better understand how these early-life factors may influence health later on. They also note that laboratory studies are still needed to confirm the relationship between gut microbes and neurodevelopment.

“The ultimate goal is to develop safe, non-intrusive early interventions such as specific probiotics or live biotherapeutics, that could help nurture a healthy gut microbiome and potentially reduce the risk of neurodevelopmental challenges,” says first author and gastroenterologist Siew Chien Ng of The Chinese University of Hong Kong.

The Life of Earth

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Chuck's picture corner to May 17, 2026

Babies are abounding in the yard, we are finally going to get 3 whole days of above average temps before they once again drop below average for at least a week and who knows beyond that. Fruit trees are beginning to bloom and most shrubs and trees are leafing out. I cut the lawn last week and the next morning had my first signs of allergy symptoms. Ahhh the winter air has also come alive.

the pear tree in bloom behind the cherry tree in bloom taken this morning

 the side yard looking green and alive

I visited Rachelle yesterday, and she has lots of birds visiting her feeders.

A rose breasted grosbeak and I haven't identified the bird on the right.

a purple leafed purple flowering crab, birds enjoy the berries later in the year.

plum blossoms

plum in bloom

I'm putting steel siding up on the house, 10' sheets vertically of black and mid grey in a checkerboard pattern.

what I can reach on the ladder, I'll be putting scaffolding up and have asked for help from the lads the first weekend of July. (any other volunteers would be welcome)

the end of another day.

the first house project of the season begins.

not sure what this weed is.

the white liloc beginning to bloom

It's hard for me to believe I planted these golden weeping willows as cutting a couple of dozen years ago

the clouds of spring

viola

driving home from the grocery store, down the hill on a street facing the river

Enjoy the day

https://chuckincardinal.blogspot.com/

Beyond Pain Relief: Scientists Discover a Protein That Could Stop Osteoarthritis in Its Tracks

By National Research Council of Sci. & Tech., May 16, 2026

https://scitechdaily.com/beyond-pain-relief-scientists-discover-a-protein-that-could-stop-osteoarthritis-in-its-tracks/

Researchers have identified a protein that appears to play a crucial role in protecting cartilage from the damage associated with osteoarthritis, a leading cause of joint pain and reduced mobility worldwide. 

Credit: Stock

Researchers have identified the SHP protein as a key regulator that suppresses cartilage-degrading enzymes and slows osteoarthritis progression.

For millions of people living with osteoarthritis, treatment options have long focused on one thing: managing pain. But while medications and injections may temporarily ease aching knees and stiff fingers, they do little to stop the slow destruction of cartilage that lies at the heart of the disease.

Now, scientists in South Korea say they may have uncovered a powerful new way to protect joints before the damage becomes irreversible.

In a new study published in Nature Communications, researchers identified a protein called SHP (NR0B2) that appears to act as a natural defender of cartilage. The team found that SHP levels decline as osteoarthritis progresses, accelerating joint deterioration. Restoring the protein in animal models not only reduced cartilage damage but also improved joint function and eased pain, raising hopes for therapies that could one day slow or even halt the disease itself.

The research was led by Dr. Chul-Ho Lee and Dr. Yong-Hoon Kim at the Laboratory Animal Resource Center of the Korea Research Institute of Bioscience and Biotechnology (KRIBB), in collaboration with Prof. JinHyun Kim at Chungnam National University Hospital.

From left: Kang Eun-jeong, researcher, and Lee Chul-ho and Kim Yong-hoon, principal researchers at KRIBB. 

Credit: KRIBB



SHP protects vulnerable cartilage

To investigate SHP’s role, the researchers analyzed cartilage tissue from osteoarthritis patients as well as animal models of the disease. They discovered that SHP protein levels dropped sharply as osteoarthritis advanced, suggesting that the loss of this protective molecule may contribute directly to cartilage breakdown.

Further experiments revealed just how important the protein may be. Mice lacking SHP developed more severe pain and experienced faster cartilage degeneration than normal mice. In contrast, restoring SHP levels in affected joints significantly reduced cartilage damage and improved mobility, highlighting the protein’s potential as a therapeutic target.
A pathway slows cartilage breakdown

The mechanistic work showed that SHP helps defend cartilage by reducing the production of enzymes that destroy the tissue, especially MMP-3 and MMP-13.

These enzymes are known to break down cartilage. For the first time, the researchers showed that SHP blocks these enzymes at the signaling level by controlling the IKKβ/NF-κB pathway, helping preserve cartilage structure.

Schematic illustration of SHP (NR0B2)-mediated protection against osteoarthritis.

 Credit: Korea Research Institute of Bioscience and Biotechnology (KRIBB)

Gene delivery reduces damage

The team then tested whether SHP could be used therapeutically through gene delivery. After injecting a viral vector carrying the SHP gene into affected joints, the researchers observed lasting benefits from a single treatment.

Even in animals that already had osteoarthritis, the approach significantly reduced cartilage damage and relieved pain.

“This study is the first to demonstrate that the SHP protein plays a critical role in protecting cartilage during the development and progression of osteoarthritis,” said Dr. Chul-Ho Lee, the study’s lead investigator. “Therapeutic strategies targeting SHP may offer a new approach to slowing or preventing osteoarthritis progression.”

The Life of Earth

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