ZOONOSIS

Wild boars could be a potential source of hepatitis E transmission to humans in the Barcelona metropolitan area

University of Barcelona team detects a close molecular similarity between the hepatitis E virus strains of wild boar and humans in this area

University of Barcelona

 

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From left to right, the experts Maria I. Costafreda, Marc López-Roig, Jordi Serra-Cobo and Abir Monastiri at the Faculty of Biology of the University of Barcelona.

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Credit: UNIVERSITY OF BARCELONA

Over the last few decades, wild boar populations have increased in the urban areas of Barcelona and in other parts of Catalonia. This wild animal is an important reservoir of the hepatitis E virus, the disease causative agent that affects more than 20 million people every year, according to the World Health Organization (WHO). Now, a team from the Faculty of Biology, the Institute for Research on Biodiversity (IRBio) of the University of Barcelona and the Faculty of Veterinary Medicine of the Universitat Autònoma de Barcelona (UAB) has identified a relevant molecular similarity between the hepatitis E virus (HEV) strains of wild boars in the metropolitan area of Barcelona and the citizens of this area. According to the researchers, these data suggest that these animals could be a source of human hepatitis E infections in the metropolitan region.

Jordi Serra-Cobo, lecturer at the UB’s Faculty of Biology and researcher at IRBio, has co-led the study with Maria Isabel Costafreda, lecturer at the Department of Genetics, Microbiology and Statistics, and researcher at the UB Nutrition and Food Safety Institute (INSA) and the Liver and Digestive Diseases Networking Biomedical Research Centre (CIBEREHD).  Jordi Serra-Cobo warns that “the results should serve to take preventive measures and be watchful against possible transmission of the hepatitis E virus from wild boars to the citizens of the Barcelona metropolitan area”. The study, published in Science of The Total Environment, also involved Abir Monastiri and Marc López-Roig (IRBio), and Maria Costafreda, along with other researchers from the Banc de Sang i Teixits (Blood and Tissue Bank of Catalonia), the Vall d’Hebron Research Institute (VHIR), the University of Lleida and the Wildlife Ecopathology Service (UAB).

An endemic virus in the wild boar population

The metropolitan area of Barcelona is made up of thirty-six municipalities, spread over 636 km2 and populated by around 3.2 million people. This area, which includes the Collserola natural park — a peri-urban Mediterranean forest of 8,000 hectares, surrounded by urban centres — has a wild boar population density of between five and fifteen individuals per square kilometre.

In the study, the researchers analysed the faeces of 312 wild boars collected in this region between 2016 and 2021, seven of which tested positive for the presence of the virus. The comparison of these samples, together with six additional samples from a previous study, has made it possible to establish “a close phylogenetic relationship” — that is, evolutionary kinship and genetic similarity — with the HEV strains from blood donors in this area. Serra-Cobo, a member of the UB’s Department of Evolutionary Biology, Ecology and Environmental Sciences, notes that “all the isolated viruses were classified within genotype 3 of HEV”.

Moreover, the wild boar samples with the virus belonged to non-adult individuals, which, according to the researchers, indicates the endemic — that is, habitual and permanent — maintenance of HEV in the wild boar population of the metropolitan area by young individuals. In this sense, they explain that “the lack of HEV detection in adult wild boars suggests that young animals are exposed to infection by the virus in the first years of life, while adults have already overcome the infection and are protected from reinfection”. “This suggests that the virus is endemic in the wild boar population in this region”, add the researchers.

A global public health problem

The growing presence of wild boars in the urban areas of Barcelona (but also in other cities such as Lugo, Rome, Berlin, Genoa or Hong Kong) is mainly due to factors such as the loss of natural habitats induced by human activities. “Given that the synurbization — the presence and adaptation of wild boar in urbanized environments — of wild boar is a global phenomenon, which is increasing and expanding, the results of this study should be useful to develop and establish programmes for monitoring, surveillance and, eventually, control of HEV both in the metropolitan area of Barcelona and in other urban areas of the world”, says Serra-Cobo.

In the article, the experts explain that “although most human cases of hepatitis E are mild, HEV infection causes approximately 50,000 human deaths each year, and is particularly serious in pregnant women, with mortality rates of up to 30%, and can be transmitted to infants”.

Prevention and information measures

Among the measures to prevent transmission of the hepatitis E virus to the public, the researchers stress the importance of avoiding “contact with wild boars, as well as not eating their raw or undercooked meat”. In cases where contact has occurred, such as with hunters or forestry agents, they recommend washing hands with soap and water. “This practice removes the lipid envelope of the virus and inactivates it”, they note.

They also highlight other measures related to pets. “Wild boars can invade the streets of central Barcelona, where they find food in rubbish bins or urban gardens. These spaces are frequented by dogs and cats, which can become infected with wild boar faeces and can contribute to spreading the infection to citizens”, warns Jordi Serra-Cobo.

In this regard, they recommend preventing household pets from coming into contact with wild animal faeces and installing systems to prevent wild boars from knocking over waste containers. The researchers also note that “it is also important to tell the public about the risk factors for the transmission of hepatitis E from wild boars, either to humans or to pets”.

Long-term monitoring of wild boars

The IRBio research group at the UB has another study underway to determine the dynamics of hepatitis E virus infection in the wild boar population in the metropolitan area of Barcelona. The researcher also stresses the “fundamental importance” of a long-term follow-up and monitoring of the health status of the wild boar population, “especially at a time when the structure and functioning of ecosystems are changing at an unprecedented rate, as a result of climate change and anthropogenic factors”.

 

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Journal

Science of The Total Environment

DOI

10.1016/j.scitotenv.2024.176871 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Endemic maintenance of human-related hepatitis E virus strains in synurbic wild boars, Barcelona Metropolitan Area, Spain

 

Shells, teeth and bones of ‘weird and wonderful organisms’ provide historical environmental clues

University of South Australia

A groundbreaking international study shows how chemical fingerprints left by “underappreciated” aquatic organisms could help scientists monitor global environmental change.

The study, led by the University of South Australia (UniSA), reveals how various understudied aquatic species act as “natural data loggers,” providing a historical record of the environment.

Lead scientist Dr Zoe Doubleday, from UniSA’s Future Industries Institute, collaborated with researchers from Canada, Croatia and the UK to synthesise hundreds of studies that analyse chemical variations in the shells, teeth, and bones of weird and wonderful organisms.

“Many aquatic organisms – like whales, seals, octopus and even algae – harbour chemical fingerprints that can give us a record of the environment over time, from historical water temperatures, pollution levels, and ecosystem health,” Dr Doubleday says. “They can also be used to predict the future.”

“Unlike traditional environmental monitoring, which can be costly and time consuming, or simply impossible, these organisms provide cheap, ready-made, archival data, which can be extracted using a scientific method called chemical sclerochronology.”

The research team compiled an extensive database of studies on “underappreciated” organisms, ranging from sponges and barnacles to marine mammals, and everything in between.

The team’s analysis has uncovered gaps in the current research landscape, highlighting previously understudied species and structures as alternative environmental indicators.

“These findings are crucial, as data on aquatic environments is both scarce and challenging to gather, especially in remote regions like the polar seas or deep oceans, both of which are sensitive to climate change,” Dr Doubleday says.

“Expanding our focus beyond traditional methods and species will allow scientists to tap into a wealth of data that’s been largely overlooked until now. It will help us to track environmental changes, species ecology, pollution and human impacts, informing conservation strategies so we can manage our ecosystems more effectively.”

“Capitalising on the wealth of chemical data in the accretionary structures of aquatic taxa: opportunities from across the tree of life” is authored by researchers from the University of South Australia; University of Toronto; Memorial University of Newfoundland and Labrador; Institute of Oceanography and Fisheries; and the University of Southampton. It is published in Limnology and Oceanography Letters.
DOI: 10.1002/lol2.10448

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Journal

Limnology and Oceanography Letters

DOI

10.1002/lol2.10448 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Capitalising on the wealth of chemical data in the accretionary structures of aquatic taxa: opportunities from across the tree of life

 

“Genetic time machine” reveals complex chimpanzee cultures

University of Zurich

 

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Education by apprenticeship in chimpanzees: One-year-old Joya watches and learns about a using toolset from her mother Jire: a stone hammer and stone anvil used to crack nuts, Bossou, Guinea, West Africa.

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Credit: Tetsuro Matsuzawa

Chimpanzees are known for their remarkable intelligence and use of tools, but could their cultures also evolve over time like human cultures? A new, multidisciplinary study led by the University of Zurich suggests that some of their most advanced behaviors may have been passed down and refined through generations.

 

In recent decades, scientists have clearly demonstrated that chimpanzees, like humans, pass on complex cultures such as tool use from generation to generation. But human culture has become vastly more sophisticated, from the Stone Age to the Space Age, as new advances have been incorporated. Chimpanzee cultures haven’t changed in the same way, which suggests that only humans have the remarkable ability to build more sophisticated cultures over time.

Scientists studying chimpanzees in the wild, however, have disputed this, suggesting that some of chimpanzees’ most complex technologies, in which they use multiple tools in sequence to extract hidden food sources, were probably built on previous knowledge over time.

Tracing genetic links

“As most chimpanzee tools, such as sticks and stems, are perishable, there are few records of their history to confirm this hypothesis – unlike human cases such as the evolution of the wheel or computer technology,” says lead author Cassandra Gunasekaram from the Department of Evolutionary Anthropology at the University of Zurich.

For the new study, a team of anthropologists, primatologists, physicists and geneticists from universities and research institutions in Zurich, St. Andrews, Barcelona, Cambridge, Konstanz and Vienna joined forces to trace genetic links between chimpanzee populations over thousands of years, using new discoveries in genetics to uncover key pieces of chimpanzee cultural history in ways never before imagined.

Early stages of cumulative culture

The authors collected information on markers of genetic similarity – genetic evidence of links between different groups of chimpanzees – as well as a range of foraging behaviors previously reported to be culturally learned, from a total of 35 chimpanzee study sites across Africa. They grouped these behaviors into those that required no tools; those that required simple tools, such as using a leaf sponge to get water from a tree hole; and the most complex behaviors that relied on a toolset.

Trading toolsets across generations

“As an example of such a toolset, chimpanzees in the Congo region first use a strong stick to dig a deep tunnel through hard soil to reach an underground termite nest,” explains Gunasekaram. “Next, they make a ‘fishing’ probe by pulling a long plant stem through their teeth to form a brush-like tip, pressing it into a point and deftly threading it down the tunnel they’ve made. They then pull it out and nibble off any defending termites that have bitten into it.”

“We made the surprising discovery that it is the most complex chimpanzee technologies – the use of entire ‘toolsets’ – that are most strongly linked across now distant populations,” says corresponding author Andrea Migliano, professor of evolutionary anthropology at UZH. “This is exactly what would be predicted if these more advanced technologies were rarely invented and even less likely to be reinvented, and therefore more likely to have been transmitted between groups.”

How female migrations spread innovation

In chimpanzees, it is sexually maturing females, rather than males, who migrate to new communities to avoid inbreeding. In this way, genes are spread between neighboring groups and then further afield over the years, centuries and millennia. The study authors discovered that it would be these same female migrations that could spread any new cultural advances to communities that lacked them.

The study also showed that when both complex toolsets and their simpler versions (i.e., mostly the components of the toolsets) occur at different study sites, the genetic markers indicate that the sites were connected in the past by female migrations. This suggests that the complex versions were built cumulatively by adding to or modifying the simple ones. “These groundbreaking discoveries provide a new way to demonstrate that chimpanzees have a cumulative culture, albeit at an early stage of development,” Migliano adds.

Eight-year-old Jeje watches and learns about using a toolset from his mother Jire: a stone hammer and stone anvil used to crack nuts, Bossou, Guinea, West Africa.

Credit

Tetsuro Matsuzawa

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Journal

Science

DOI

10.1126/science.adk3381 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Population connectivity shapes the distribution and complexity of chimpanzee cumulative culture

Article Publication Date

27-Nov-2024

Marxists.orgwww.marxists.org/archive/marx/works/1876/part-played-labour/

The Part Played by Labour in the Transition from Ape to Man

Hundreds of thousands of years – of no greater significance in the history of the earth than one second in the life of man [Engels note: A leading authority in ...

 

Brains grew faster as humans evolved, study shows

University of Reading

Modern humans, Neanderthals, and other recent relatives on our human family tree evolved bigger brains much more rapidly than earlier species, a new study of human brain evolution has found. 

The study, published today (Tuesday, 26 November) in the journal PNAS, overturns long-standing ideas about human brain evolution. Scientists from the University of Reading, the University of Oxford and Durham University found that brain size increased gradually within each ancient human species rather than through sudden leaps between species.

The team assembled the largest-ever dataset of ancient human fossils spanning 7 million years and used advanced computational and statistical methods to account for gaps in the fossil record. These innovative approaches provided the most comprehensive view yet of how brain size evolved over time.

Professor Chris Venditti, co-author of the study from the University of Reading, said: "This study completely changes our understanding of how human brains evolved. It was previously thought that brain size jumps dramatically between species, like new upgrades between the latest computer models. Our study instead shows a steady, incremental ‘software update’ happening within each species over millions of years.”

The research challenges old ideas that some species, like Neanderthals, were unchanging and unable to adapt and instead highlights gradual and continuous change as the driving force behind brain size evolution.

Dr Thomas Puschel, lead author now at Oxford University, said: “Big evolutionary changes don’t always need dramatic events. They can happen through small, gradual improvements over time, much like how we learn and adapt today.”

Brains, bodies, and evolutionary scale

The researchers also uncovered a striking pattern: while larger-bodied species generally had bigger brains, the variation observed within an individual species did not consistently correlate with body size. Brain size evolution across long evolutionary timescales extending millions of years is therefore shaped by different factors to those observed within individual species – highlighting the complexity of evolutionary pressures on brain size. 

Dr Joanna Baker, co-author from the University of Reading, said: “Why and how humans evolved large brains is a central question in human evolution. By studying brain and body size in  various species over millions of years, we reveal that our hallmark large brains arose primarily from gradual changes within individual species.”

The study was produced as part of a £1 million Research Leadership Awards grant from the Leverhulme Trust. The project was to better understand the evolution of human ancestors. 

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2409542121 

Method of Research

Imaging analysis

Subject of Research

Not applicable

Article Title

Hominin brain size increase has emerged from within-species encephalization

Article Publication Date

26-Nov-2024

 

Soccer heading damages brain regions affected in CTE

Radiological Society of North America

 

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Diffusion MRI shows the effect of soccer heading on brain regions. RHI = repetitive head impacts

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Credit: Radiological Society of North America (RSNA) and Michael L. Lipton, M.D., Ph.D.

CHICAGO – Soccer heading may cause more damage to the brain than previously thought, according to a study being presented next week at the annual meeting of the Radiological Society of North America (RSNA).

Heading is a widely used technique in soccer where the players control the direction of the ball by hitting it with their head. In recent years, research has been done that suggests a link between repeated head impacts and neurodegenerative diseases, such as chronic traumatic encephalopathy (CTE).

“The potential effects of repeated head impacts in sport are much more extensive than previously known and affect locations similar to where we’ve seen CTE pathology,” said study senior author Michael L. Lipton, M.D., Ph.D., professor of radiology at Columbia University Irving Medical Center in New York. “This raises concern for delayed adverse effects of head impacts.”

While prior studies have identified injuries to the brain’s white matter in soccer players, Dr. Lipton and colleagues utilized a new approach to an advanced brain imaging technique called diffusion MRI to analyze microstructure close to the surface of the brain. 

To identify how repeated head impacts affect the brain, the researchers compared brain MRIs of 352 male and female amateur soccer players, ranging in age from 18 to 53, to brain MRIs of 77 non-collision sport athletes, such as runners.

Soccer players who headed the ball at high levels showed abnormality of the brain’s white matter adjacent to sulci, which are deep grooves in the brain’s surface. Abnormalities in this region of the brain are known to occur in very severe traumatic brain injuries.

The abnormalities were most prominent in the frontal lobe of the brain, an area most susceptible to damage from trauma and frequently impacted during soccer heading. More repetitive head impacts were also associated with poorer verbal learning.

“Our analysis showed that the white matter abnormalities represent a mechanism by which heading leads to worse cognitive performance,” Dr. Lipton said.

Most of the participants of the study had never sustained a concussion or been diagnosed with a traumatic brain injury. This suggests that repeated head impacts that don’t result in serious injury may still adversely affect the brain.

“The study identifies structural brain abnormalities from repeated head impacts among healthy athletes,” Dr. Lipton said. “The abnormalities occur in the locations most characteristic of CTE, are associated with worse ability to learn a cognitive task and could affect function in the future.”

The results of this study are also relevant to head injuries from other contact sports. The researchers stress the importance of knowing the risks of repeated head impacts and their potential to harm brain health over time.

“Characterizing the potential risks of repetitive head impacts can facilitate safer sport engagement to maximize benefits while minimizing potential harms,” Dr. Lipton said. “The next phase of the study is ongoing and examines the brain mechanisms underlying the MRI effects and potential protective factors.”

Co-authors are Bluyé Demessie, A.B., M.S., Walter F. Stewart, Ph.D., Richard B. Lipton, M.D., Molly E. Zimmerman, Ph.D., Mimi Kim, Sc.D., Kenny Ye, Ph.D., Thomas Kaminski and Roman Fleysher, Ph.D.

This study was funded by the National Institutes of Health and The Dana Foundation.

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Note: Copies of RSNA 2024 news releases and electronic images will be available online at RSNA.org/press24.

RSNA is an association of radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Illinois. (RSNA.org)

For patient-friendly information on brain MRI, visit RadiologyInfo.org

 

Concussions slow brain activity of high school football players

Radiological Society of North America

 

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Magnetoencephalography (MEG) equipment. Pre- and post-season resting-state MEG data was collected from 91 high school football players, of whom 10 were diagnosed with a concussion. MEG is a neuroimaging technique that measures the magnetic fields that the brain’s electrical currents produce.

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Credit: Radiological Society of North America (RSNA)

CHICAGO – A new study of high school football players found that concussions affect an often-overlooked but important brain signal. The findings are being presented next week at the annual meeting of the Radiological Society of North America (RSNA).

Reports have emerged in recent years warning about the potential harms of youth contact sports on developing brains. Contact sports, including high school football, carry a risk of concussion. Symptoms of concussion commonly include cognitive disturbances, such as difficulty with balancing, memory or concentration.

Many concussion studies focus on periodic brain signals. These signals appear in rhythmic patterns and contribute to brain functions such as attention, movement or sensory processing. Not much is known about how concussions affect other aspects of brain function, specifically, brain signals that are not rhythmic.

“Most previous neuroscience research has focused on rhythmic brain signaling, which is also called periodic neurophysiology,” said study lead author Kevin C. Yu, B.S., a neuroscience student at Wake Forest University School of Medicine in Winston-Salem, North Carolina. “On the other hand, aperiodic neurophysiology refers to brain signals that are not rhythmic.”

Aperiodic activity is typically treated as ‘background noise’ on brain scans, but recent studies have shown that this background noise may play a key role in how the brain functions.

“While it’s often overlooked, aperiodic activity is important because it reflects brain cortical excitability,” said study senior author Christopher T. Whitlow, M.D., Ph.D., M.H.A., Meschan Distinguished Professor and Enterprise Chair of Radiology at Wake Forest University School of Medicine.

Cortical excitability is a vital part of brain function. It reflects how nerve cells, or neurons, in the brain’s cortex respond to stimulation and plays a key role in cognitive functions like learning and memory, information processing, decision making, motor control, wakefulness and sleep.

To gain a better understanding of brain rhythms and trauma, the researchers sought to identify the impacts of concussions on aperiodic activity.

Pre- and post-season resting-state magnetoencephalography (MEG) data was collected from 91 high school football players, of whom 10 were diagnosed with a concussion. MEG is a neuroimaging technique that measures the magnetic fields that the brain’s electrical currents produce.

A clinical evaluation tool for concussions called the Post-Concussive Symptom Inventory was correlated with pre- and post-season physical, cognitive and behavioral symptoms.

High school football players who sustained concussions displayed slowed aperiodic activity. Aperiodic slowing was strongly associated with worse post-concussion cognitive symptoms and test scores.

Slowed aperiodic activity was present in areas of the brain that contain chemicals linked with concussion symptoms like impaired concentration and memory.  

“This study is important because it provides insight into both the mechanisms and the clinical implications of concussion in the maturing adolescent brain,” said co-lead author Alex I. Wiesman, Ph.D., assistant professor at Simon Fraser University in Burnaby, British Columbia, Canada. “Reduced excitability is conceptually a very different brain activity change than altered rhythms and means that a clear next step for this work is to see whether these changes are related to effects of concussion on the brain’s chemistry.”

The results highlight the importance of protective measures in contact sports. The researchers cautioned that young players should always take the necessary time to fully recover from a concussion before returning to any sport.

The findings from the study may also influence tracking of post-concussion symptoms and aid in finding new treatments to improve recovery.

“Our study opens the door to new ways of understanding and diagnosing concussions, using this novel type of brain activity that is associated with concussion symptoms,” Dr. Whitlow said. “It highlights the importance of monitoring kids carefully after any head injury and taking concussions seriously.”

Other co-authors are Elizabeth M. Davenport, Ph.D., Laura A. Flashman, Ph.D., Jillian Urban, Ph.D., Srikantam S. Nagarajan, Ph.D., Kiran Solingapuram Sai, Ph.D., Joel Stitzel, Ph.D., and Joseph A. Maldjian, M.D.

This work was supported by the National Institutes of Health (NIH) grants R01NS082453 and R01NS091602, NIH grant F32-NS119375, a Canadian Institutes of Health Research (CIHR) Banting Postdoctoral Fellowship (BPF-186555), and a CIHR Canada Research Chair (CRC-2023-00300).

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Note: Copies of RSNA 2024 news releases and electronic images will be available online at RSNA.org/press24.

RSNA is an association of radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Illinois. (RSNA.org)

For patient-friendly information on brain imaging, visit RadiologyInfo.org.

 

The melting of Greenland: a climate challenge with major implications for the 21st century

Climatologists and engineers are calling for urgent action to curb global warming and protect vulnerable regions

University of Liège

 

image: 

The map shows the annual mass gain/loss by model at the end of the century, compared with the end of the last century. Values are expressed in “water equivalent millimeters”.

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Credit: @Université de Liège / Q.Glaude

The melting of Greenland is accelerating, with an estimated loss of between 964 and 1735 gigatonnes of ice per year by 2100 in a scenario of high greenhouse gas emissions (SSP585), according to three regional climate models. This melting will lead to a rise in sea levels of up to one metre, threatening millions of people in coastal areas. New research conducted by the University of Liège and supported in particular by its NIC5 supercomputer will contribute to future IPCC assessments.

Greenland's glaciers are melting at an alarming rate. Two recent studies, one coordinated by the University of Liège and published in Geophysical Research Letters, the other published in a scientific press release, reveal the scale of the problem. Three regional climate models (RACMO, MAR and HIRHAM) offer varying predictions for the melting of the ice, but all agree on one conclusion: Greenland will lose a massive amount of ice by 2100, accelerating the rise in sea levels.

According to the projections, the ice sheet could lose between 964 and 1735 gigatonnes of ice per year by the end of the century, depending on the model used," explains Quentin Glaude, an engineer at the Montefiore Insitute at ULiège.  These differences, although significant, do not hide the essential fact: the melting of the ice is an irreversible process if greenhouse gas emissions are not drastically reduced". The research team pointed out that these differences stem from the way in which each model treats the flow of meltwater. For example, when snow melts, some of the water infiltrates and refreezes, while the rest flows directly into the ocean. This complex process, influenced by feedbacks linked to albedo (surface reflectivity), is a key factor in the discrepancies between the models.

"Greenland currently contributes 25% to global sea level rise, or 0.6 mm per year. If the current melting continues, this contribution could reach up to 1 metre by 2100," adds Xavier Fettweis, climatologist at ULiège. This would put millions of lives at risk in coastal areas around the world, exposed to increased risks of flooding and submersion". The research results that have just been published were made possible by the Walloon region's high-performance computing infrastructure, in particular the NIC5 supercomputer at the University of Liège. These tools make it possible to explore complex climate scenarios by simulating the interactions between ice, the atmosphere and the oceans.

Towards even more accurate models

Despite their advances, the researchers insist on the need to improve the climate models. A better understanding of the processes involved in retaining water in the snow and the integration of dynamic parameters, such as changes in the altitude of the ice sheet, are essential to reduce uncertainties.

This work, the fruit of collaboration between European institutions, illustrates the importance of cooperation in the face of global climate challenges. The results obtained will be incorporated into future IPCC assessments, helping to refine projections of sea-level rise.

The melting of the Greenland ice sheet is a wake-up call that cannot be ignored. It calls for immediate action to limit global warming, protect vulnerable communities and preserve the world's ecosystems.

Time series, tracking the annual mass balance over the entire ice sheet.

Credit

Université de Liège / Q.Glaude

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Journal

Geophysical Research Letters

DOI

10.1029/2024gl111902 

Article Title

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL111902

Article Publication Date

21-Nov-2024

 

Air pollution linked to longer duration of long-COVID symptoms

New study explores the association between different environmental exposures and Long-COVID in a Catalan population cohort

Barcelona Institute for Global Health (ISGlobal)

Exposure to air pollutants (PM2.5 and PM10) is associated with an increased risk of persistent long-COVID symptoms, partly due to its impact on the severity of the acute infection. This is the main conclusion of a study led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by “la Caixa” Foundation, in collaboration with the Germans Trias i Pujol Research Institute (IGTP), and published in Environmental Health Perspectives. 

Long-COVID is a heterogeneous condition in which symptoms like fatigue, breathlessness, and cognitive issues persist for months after a COVID-19 infection and cannot be explained by other diagnoses. The real burden of long-COVID remains unclear, but millions of people are estimated to be affected worldwide. Its risk factors are also not well understood, since even people with mild or no symptoms during acute infection can develop long-COVID.

“We previously found that air pollution exposure is linked to a higher risk of severe COVID-19 and a lower vaccine response, but there are very few studies on long-COVID and the environment,” explains Manolis Kogevinas, ISGlobal researcher and senior author of the study. In this study, he and his colleagues investigated whether air pollution and other environmental exposures such as noise, artificial light at night, and green spaces, were associated with the risk- or persistence- of Long-COVID.

The study followed over 2,800 adults of the COVICAT cohort, aged 40- 65 years living in Catalonia who during the pandemic completed three online questionnaires (2020, 2021, 2023). These surveys collected information on COVID-19 infections, vaccination status, health status, and sociodemographic data. Researchers estimated residential exposure to noise, particulate matter, ozone, nitrogen dioxide, green spaces, and light at night for each participant.

Long-COVID risk factors

The analysis showed that one in four people who contracted COVID-19 experienced lingering symptoms for three months or more, with 5% experiencing persistent symptoms for two years or more. Women, individuals with lower education levels, those with prior chronic conditions, and those who had severe COVID-19 were at highest risk of long-COVID. Vaccination, on the other hand, made a positive difference: only 15% of vaccinated participants developed long-COVID compared to 46% of unvaccinated ones.

Air pollution and persistent long-COVID

Exposure to particulate matter (PM2.5 and PM10) in the air was associated with a slight increase in the risk of persistent long-COVID (i.e. people who reported long-Covid in 2021 and whose symptoms were still present the last week before the 2023 interview). The risk of persistent long-COVID increased linearly with greater exposure to particulate matter in the air. In contrast, factors such as nearby green spaces or traffic noise showed little impact on long-COVID.

The researchers note that while air pollution may not directly cause long-COVID, it could increase the severity of the initial infection, which, in turn, raises the risk of long COVID. “This hypothesis is supported by the association between particulate matter and the most severe and persistent cases of long-COVID, but not with all cases of long-COVID,” says Apolline Saucy, first author of the study.

Further research is needed to break down the different types of long-term symptoms and get a more detailed picture of how environmental factors might play a role.  “This type of studies is particularly relevant as more people continue to recover from COVID-19 and deal with its potential long-term effects,” says Kogevinas.

 

About COVICAT

The COVICAT cohort is a COVID-19-population-based cohort designed to characterize the health impact of the COVID-19 pandemic on the population in Catalonia, Spain. Baseline data originates from the GCAT (Genomes for Life) project of the Germans Trias i Pujol Research Institute (IGTP).

 

Reference

Saucy A, Espinosa A, Iraola-Guzman S, Castaño-Vinyals G, Harding BN, Karachaliou M, Ranzani I, De Cid R, Garcia-Aymerich J, Kogevinas M. Environmental exposures and Long-COVID in a Prospective Population-Based Study in Catalonia (COVICAT study). Environmental Health Perspectives. 2024. https://doi.org/10.1289/EHP15377

 

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Journal

Environmental Health Perspectives

DOI

10.1289/EHP15377 

Method of Research

Observational study

Subject of Research

People

Article Title

Environmental exposures and Long-COVID in a Prospective Population-Based Study in Catalonia (COVICAT study)

Article Publication Date

27-Nov-2024