Category: Science

A new analysis of lice genetic diversity suggests that they came to the Americas twice—once during the first wave of human migration across the Bering Strait, and again during European colonization.

Marina Ascunce, who conducted the research at the Florida Museum of Natural History, and colleagues report these findings in the journal PLOS ONE.

The human louse is a wingless, blood-sucking parasite that lives its entire life on its host. It is one of the oldest known parasites to live on humans, and the two species have coevolved for millennia. Due to this intimate relationship, studying lice can offer clues to how humans evolved as well. In the new study, researchers analyzed the genetic variation in 274 human lice from 25 geographic sites around the world.

A genetic analysis based on louse DNA revealed the existence of two distinct clusters of lice that rarely interbred. Cluster I had a worldwide distribution, while cluster II was found in Europe and the Americas. The only lice with ancestry from both clusters are found in the Americas. This distinct group appears to be the result of a mixture between lice descended from populations that arrived with the First People and those descended from European lice, which were brought over during the colonization of the Americas.

The researchers also identified a genetic relationship between lice in Asia and Central America. This supports the idea that people from East Asia migrated to North America and became the first Native Americans. These people then spread south into Central America, where modern louse populations today still retain a genetic signature from their distant Asian ancestors.

The patterns observed in the new study support existing ideas about human migration and provide additional knowledge about how lice have evolved. The researchers point out that they selected genetic markers that evolve quickly and are best suited to recent events. Thus, future studies that use markers that have changed more slowly could shed light on more ancient events. Additionally, the methods developed for this work could guide the development of new analyses to study other host-parasite systems.

The authors add: “Human lice are more than annoying human parasites, they are ‘satellites’ of our evolution. Because human lice feed on human blood, they need us to survive, and over millions of years this resulted in a long co-evolutionary history together.”

Coauthors are from the Consejo Nacional de Investigaciones Científicas y Técnica; the Universidad Nacional Autónoma de México; and the University of Florida.

Funding for the study came in part from the Consejo Nacional de Investigaciones Científicas y Técnica; the Consejo Nacional de Ciencia y Tecnología; and the National Science Foundation.

Source: University of Florida

Extended family members can play a significant role in peoples’ lives during extreme events, new research shows.

“Often, surveys don’t ask about relationships with extended kin. The focus is on the nuclear family,” says Megan Reed, an assistant professor of sociology at Emory University and first author of the study in Socius: Sociological Research for a Dynamic World. “This research shows us that people have a pretty large network that they activate in times of crisis.”

Reed and her coauthors previously argued for more research on the role of “extended kin,” such as aunts and uncles in family relationships. They joined forces with researchers running the Robin Hood Poverty Tracker at Columbia University to include questions about those relationships in a phone survey that took place shortly after COVID-19 hit the United States.

Their study documents how often more than 2,300 New Yorkers communicated with “non-coresident kin” following the first wave of the pandemic in 2020. The terminology refers to any family members not residing in the same household, from adult siblings and parents to more distant kin such as cousins.

Among the key findings:

• About 49% of their sample increased communication with non-coresident kin since the pandemic began. Nearly a third reported increasing communication with siblings, which was the relationship that saw the greatest jump.
• About 56% of the respondents reported speaking to family outside their household several times a week.
• Slightly more than 14% of people increased communication with cousins, while slightly less than 14% increased communication with aunts and uncles.

The researchers did not find any variation by age, which suggests that much of the communication was intergenerational or that the impact of the pandemic on family relationships was similar across different age groups.

Beyond age, though, there were other demographic differences. Black and Hispanic respondents were more likely to report increased communication, for instance, as were foreign-born respondents and women.

The survey did not attempt to characterize how the communication occurred, though Reed says other research has shown an increased use of group chats and phone calls when the pandemic limited in-person gatherings.

It also does not address the nature of the communication, such as what respondents discussed during the exchanges.

“Family relationships can play an important role in resiliency in the face of crisis,” Reed says. “Our study provides new evidence of the activation of these relationships during the COVID-19 pandemic.”

Additional coauthors are from New York University-Abu Dhabi; the University of New Hampshire; and the University of Pennsylvania.

Source: April Hunt for Emory University

After that first Thanksgiving, the event receded from memory for two centuries. Then, in the early 1800s, some shaky historical evidence of that 17th century meal was unearthed. Amid a lot of tension over slavery and immigration, some leaders sought to elevate the bit of Colonial history as a unifying project that could bring a divided nation together. From there, the influence of home economics, advertising, industrial food production, animal science, factory farm breeding, and other transformations have made the Thanksgiving meal into one of abundance, standardization, and shortcut home cooking.

Sarah Josepha Hale, the editor of a very popular women’s magazine called Godey’s Lady’s Book, wanted to create a Thanksgiving celebration as a project of national unity. For many years, she petitioned sitting presidents to make Thanksgiving a national holiday. She finally succeeded with Abraham Lincoln during the Civil War, when he passed the Thanksgiving Proclamation in October 1863.

Lincoln doesn’t actually reference the 1621 event at all, but he suggested that the Thanksgiving holiday was about national unity in the midst of the Civil War—a project I think we can all get behind.

Over a third of American adults are worried that they or someone in their family will get the seasonal flu, COVID-19, or RSV in the next three months, according to a new health survey.

Those three viral illnesses made up the “tripledemic” of respiratory illnesses that overwhelmed some health care facilities last winter. Although RSV (respiratory syncytial virus) typically peaks later in the year, this month hospitals in parts of Texas are already seeing emergency rooms filled with children.

RSV is a common respiratory virus that often causes mild, cold-like symptoms but can be serious and require hospitalization among infants and older adults, according to the Centers for Disease Control and Prevention (CDC).

There’s no consensus among US adults about which virus is more likely to cause severe illness: 22% say COVID-19; 13% say RSV; 7% say seasonal flu; and 41% say they are equally likely to cause severe illness. Sixteen percent are not sure, according to the survey from the Annenberg Public Policy Center (APPC) of the University of Pennsylvania.

The Annenberg Science and Public Health Knowledge (ASAPH) survey, which took place October 5-12, 2023, with a panel of over 1,500 US adults, finds that Americans generally are more knowledgeable about RSV today than earlier this year. Over the spring and summer, health authorities approved new vaccines against RSV specifically for adults ages 60 and older and for pregnant people to protect their newborns.

Key findings

RSV concern: 35% worry that they or someone in their family will get RSV in the next three months, up from 32% in January 2023. About two-thirds (65%) are not worried.

COVID-19 concern: 35% are worried that they or someone in their family will get COVID-19 in the next three months, up from 21% in August 2023 but similar to last winter (36% in January 2023). About two-thirds (65%) are not worried.

Flu concern: 39% are worried that they or someone in their family will contract the seasonal flu in the next three months, statistically unchanged from January 2023. Six in 10 people (61%) are not worried.

Complications: Nearly 1 in 3 people (31%) say they personally know someone who believes they are suffering long-term health complications as a result of getting infected with COVID-19. One in 6 (17%) say they personally know someone who believes they are suffering long-term health complications as a result of getting infected with COVID-19.

Fewer say they’ve had a flu shot: At the time the survey was fielded (October 5-12, 2023), 21% said they had received the flu shot this season, compared with 26% in mid-October 2022 and 38% in the second week of November 2021.

“Because getting a flu shot yearly not only helps to protect us from serious infection but also predicts our acceptance of other CDC-recommended vaccines, the drop in reported flu vaccination we see reflected in our panel is worrisome,” says Kathleen Hall Jamieson, director of the Annenberg Public Policy Center and director of the survey.

The survey data come from the 13th wave of a nationally representative panel of 1,559 US adults, first empaneled in April 2021, conducted for the Annenberg Public Policy Center by SSRS an independent market research company. This wave of the Annenberg Science and Public Health Knowledge (ASAPH) survey was fielded October 5 to 12, 2023, and has a margin of sampling error (MOE) of ± 3.4 percentage points at the 95% confidence level. All figures are rounded to the nearest whole number and may not add to 100%. Combined subcategories may not add to totals in the topline and text due to rounding.

Source: Penn

The discovery of 27 avian footprints on the southern Australia coast—dating back to the Early Cretaceous when Australia was still connected to Antarctica—opens another window onto early avian evolution and possible migratory behavior.

PLOS ONE published the discovery of some of the oldest, positively identified bird tracks in the Southern Hemisphere, dated to between 120 million and 128 million years ago.

“Most of the bird tracks and body fossils dating as far back as the Early Cretaceous are from the Northern Hemisphere, particularly from Asia,” says Anthony Martin, first author of the study and a professor in Emory University’s department of environmental sciences. “Our discovery shows that there were many birds, and a variety of them, near the South Pole about 125 million years ago.”

Martin is a geologist and paleontologist focused primarily on ichnology—the study of traces of life such as tracks, burrows, nests, and tooth marks.

The 27 bird tracks vary in form and size and are among the largest known from the Early Cretaceous. They range from 7 to 14 centimeters (2.75 to 5.5 inches) wide, which is similar to tracks of modern-day shorebirds, such as small herons and oystercatchers.

The tracks were found in the Wonthaggi Formation south of Melbourne. The rocky coastal strata mark where the ancient supercontinent Gondwana began to break up around 100 million years ago when Australia separated from Antarctica.

The polar environment at that time was a rift valley with braided rivers. Although the mean annual air temperature was higher during the Cretaceous than today, during the polar winters the ecosystem experienced deep, freezing temperatures and months of darkness.

The Wonthaggi avian tracks occurred on multiple stratigraphic levels, indicating a recurrent presence of a variety of birds. It also suggests seasonal formation of the tracks during polar summers, perhaps on a migratory route.

“The birds would likely have been stepping on soft sand or mud,” Martin says. “Then the tracks may have been buried by a gentle river flow that deposited more sand or mud on top of them.”

The Wonthaggi Formation is famous for its variety of polar dinosaur bones, although bird-fossil finds are extremely rare. The Cretaceous strata of the formation has yielded only one tiny bird bone—a wishbone—and a few feathers.

“Birds have such thin and tiny bones,” Martin says. “Think of the likelihood of a sparrow being preserved in the geologic record as opposed to an elephant.”

Birds are also lightweight and don’t leave much of a foot impression, he adds.

Martin and colleagues discovered two 105-million-year-old bird tracks in Australia’s Eumeralla Formation in 2013, making them the oldest from Australia at the time.

Coauthor Melissa Lowery, a local volunteer fossil hunter for Monash University, first spotted some of the tracks in the current discovery in 2020. Dubbed “the doyenne of dinosaur discovery,” Lowery has found hundreds of bones and more than 100 dinosaur footprints.

“Melissa is incredibly skilled at finding fossil tracks,” Martin says. “Some of these tracks are subtle even for me, and I have lots of experience and training.”

Most of the tracks were only exposed at low tide and some of them were encrusted by marine life such as algae, barnacles, and mollusks.

Due to international travel restrictions in Australia during the COVID-19 pandemic, Martin had to wait until 2022 before he could travel to the site to lead the analyses of the tracks.

He was joined in the field by coauthors Patricia Vickers-Rich, professor of paleontology at Monash University, and Thomas Rich, curator of vertebrate paleontology at Museums Victoria Research Institute. The couple have led a major effort since the 1970s to uncover fossils in the Australian state of Victoria and to interpret the biota of Gondwana.

Also assisting in the field analyses were coauthors Mike Hall, a geologist at Monash University, and Peter Swinkels, a taxidermist at Museums Victoria Research Institute and an expert at preserving specimens through moldings and casts.

“At first I thought the tracks might have been made by young theropods,” Martin says of the footprints. “But I soon realized they were bird tracks.”

The fossil record indicates that birds evolved from theropods, a bipedal, carnivorous dinosaur clade. The theropod Tyrannosaursus rex, for instance, had a vestigial rear toe—evidence that T. rex shared a common ancestor with birds.

“In some dinosaur lineages, that rear toe got longer instead of shorter and made a great adaptation for perching up in trees,” Martin explains.

In 1998, scientists began uncovering fossils in China of small theropods sprouting hair-like filaments that appeared to be proto-feathers. Dubbed the Sinosauropteryx, or “Chinese dragon bird,” the small theropod lived in northeastern China during the Early Cretaceous.

The earliest-known fossil classified as a bird is Archaeopteryx lithographica. First found in 1861 in a Jurassic limestone from southern Germany, Archaeopteryx dates to about 150 million years ago and appears to be a transitional form between theropods and the birds we are familiar with today. Archaeopteryx had full-fledged feathers, a long bony tail, hands with fingers and a full set of teeth.

In 2021, paleontologists working in Brazil uncovered the fossil of a bird that lived in the Early Cretaceous about 115 million years ago. Dubbed Kaririavis mater, it combined some primitive and modern avian characteristics.

A nine-mile-wide asteroid slammed into the Earth 66 million years ago, striking the northern edge of the Yucatán peninsula at a site known as Chicxulub. The impact spewed massive amounts of debris into the air sparking a mass extinction.

“The only dinosaurs to survive the meteor impact were birds,” Martin says. “We don’t know why. My hypothesis is that there were some birds that nested underground and that behavior may have protected them.”

Many other mysteries remain about the evolution of birds and their behaviors.

The discovery of the Australian bird tracks raises questions about where the birds originated and whether the polar environment was part of a migratory route.

The thinness of the toes relative to the track lengths, the wide angles between the toes and the thin, sharp claws and rear toes on some of the tracks helped Martin to verify their avian identity.

Coauthor Claudia Serrano-Brañas, a paleontologist at the Benemérita Normal School of Coahuila and the National Museum of Natural History, Smithsonian Institution, verified similarities between the Australian bird footprints and ancient bird footprints from other parts of the world.

Swinkels created resin casts of the Australian tracks that brought into greater relief some of the nuances of the impressions. The casts provide a tool for further study. They also serve to preserve the finds. The silty, sandstone beds containing the footprints are rapidly eroding under the coastal tides and waves.

“Seven of the tracks that Melissa found in 2020 are no longer there,” Martin says. “Some fossils, including tracks, are exposed only for a brief amount of time after being buried for millions of years. We humans have to rush in and document them before they disappear again.”

Source: Emory University

Shorter-term fostering programs at animal shelters vastly improve dog adoptions, a study finds.

Spending time with a dog is one of the most consistently effective ways to improve a dog’s life in the shelter. Time out of the kennel with a person can reduce physiological measures of stress, as can a single night or more in a foster caregiver’s home.

In this study, the researchers assessed the effects of outings of just a few hours and fostering stays of one to two nights on dogs’ length of stay in the shelter and their adoption outcomes.

The researchers found that brief outings and temporary fostering stays increased dogs’ likelihood of adoption by five and more than 14 times, respectively. The team also found that these programs were more successful when a greater proportion of community members were providing outings and stays to the shelters’ dogs, as well as when shelter with more resources carried out these programs.

“…even the best shelters are not good places for dogs to be living.”

A paper on the findings appears in the journal Animals.

In previous work, the team investigated how outings and temporary fostering stays influenced dogs’ stress and activity levels but did not consider if these experiences helped homeless canines find their forever homes. The answer, based on the research, is yes.

“It’s a really exciting finding. Our prior work showed how beneficial sleepovers were for reducing dogs’ stress,” says Erica Feuerbacher, associate professor in the School of Animal Sciences who spearheaded the study with assistant professor Lisa Gunter. “It’s wonderful to know that it also helps them get adopted.”

The results show that for foster outings, about 4% of the people ended up adopting the dog. For overnight stays, the number increased to about 12%. Both results show that the vast majority of adopters were not the foster families.

“We saw that the majority of people adopting the dogs weren’t the caregivers that were taking the dogs on outings or letting them stay in their homes. These dogs were being seen in the community, meeting new people, and caregivers were sharing their stories,” Gunter says. “This increased exposure likely helped the dogs find their adopters.”

The researchers analyzed data from 51 animal shelters in the United States on 1,955 dogs that received these fostering interventions as well as 25,946 dogs residing at these shelters that served as the study’s controls. Over four years, 85 shelter partners helped the research team carry out studies on brief outings, temporary stays, foster caregiving during the pandemic, weeklong fostering, and safety net fostering for pets whose owners were experiencing hardship.

While dogs’ lengths of stay in this study were longer in comparison to dogs that did not receive a brief outing or temporary fostering, this difference was present prior to the intervention, suggesting that shelters are using these programs for dogs that need more help in finding homes. After going on an outing or fostering stay, dogs waited just 10 days to be adopted.

“Our data show that these programs can help the dogs not only have an improved experience in the shelter, but also dramatically increase their likelihood of adoption, and for the shelters that get their communities involved in brief outings and temporary fostering stays, better performing programs,” Gunter says.

“It’s great news that even short-term fostering has positive impacts on shelter dogs’ welfare and helps them get adopted because there are so many dogs in shelters in the United States and even the best shelters are not good places for dogs to be living,” says project leader Clive Wynne of Arizona State University.

The increase in dog adoptions with short-term foster programs underscores their value to local shelters, the researchers say. Their findings highlight the importance of having resources available to shelters to support these programs. These programs are not as easy for some shelters as they are for others—it takes support both financial and human.

“These kinds of fostering programs can save the lives of dogs in shelters,” Gunter says. “Currently, shelters are struggling with dog adoptions, and we have evidence that these programs support placement into homes, which in turn can help shelters help more dogs.”

Wynne also sees the future of this work as easy to implement for shelters.

“One of the beauties of this program of research is that the fostering intervention is relatively low cost for shelters,” Wynne says. “More than anything else, what shelters need is education on how to implement fostering, and helping them with that was an important aspect of this research program.”

The project has funding from Maddie’s Fund.

Source: Virginia Tech

A first-of-its-kind study has revealed a new culprit in the formation of brain hemorrhages that does not involve injury to the blood vessels, as previously believed.

Researchers discovered that interactions between aged red blood cells and brain capillaries can lead to cerebral microbleeds, offering deeper insights into how they occur and identifying potential new therapeutic targets for treatment and prevention.

The findings, published in the Journal of Neuroinflammation, describe how the researchers were able to watch the process by which red blood cells stall in the brain capillaries and then observe how the hemorrhage happens.

Cerebral microbleeds are associated with a variety of conditions that occur at higher rates in older adults, including hypertension, Alzheimer’s disease, and ischemic stroke.

“We have previously explored this issue in cell culture systems, but our current study is significant in expanding our understanding of the mechanism by which cerebral microbleeds develop,” says co-corresponding author Mark Fisher, professor of neurology in the University of California, Irvine School of Medicine. “Our findings may have profound clinical implications, as we identified a link between red blood cell damage and cerebral hemorrhages that occurs at the capillary level.”

The team exposed red blood cells to a chemical called tert-butyl hydroperoxide that caused oxidative stress; the cells were then marked with a fluorescent label and injected into mice.

Using two different methods, the researchers observed the red blood cells getting stuck in the brain capillaries and then being cleared out in a process called endothelial erythrophagocytosis. As they moved out of the capillaries, microglia inflammatory cells engulfed the red blood cells, which led to the formation of a brain hemorrhage.

“It has always been assumed that in order for cerebral hemorrhage to occur, blood vessels need to be injured or disrupted. We found that increased red blood cell interactions with the brain capillaries represent an alternative source of development,” says co-corresponding author Xiangmin Xu, professor of anatomy and neurobiology and director of the campus’s Center for Neural Circuit Mapping.

“We need to examine in detail the regulation of brain capillary clearance and also analyze how that process may be related to insufficient blood supply and ischemic stroke, which is the most common form of stroke, to help advance the development of targeted treatments.”

The National Institute on Aging and the National Institute of Neurological Disorders and Stroke funded the work.

Source: UC Irvine

After former President Donald Trump announced the end of the Deferred Action for Childhood Arrivals (DACA) program in 2017, its beneficiaries experienced significantly higher levels of distress and post-traumatic stress diagnoses than their non-DACA counterparts, according to a new study.

President Joe Biden has pledged to preserve DACA, but its future remains uncertain. As a result, stress is prevalent for those who benefit from the program, the researchers write.

For the study, published in Psychological Trauma: Theory, Research, Practice and Policy, the researchers examined the association between immigration legal status and distress from the announcement of DACA’s termination among individuals affected by the loss of the program.

Approximately 40% of the 233 individuals surveyed met the clinical cutoff for psychological distress.

DACA recipients had significantly higher levels of distress, even when compared to non-DACA immigrants with unauthorized immigration legal status, notes lead author Luz Garcini, assistant professor of psychological sciences and interim director of community and public health at the Kinder Institute for Urban Research at Rice University.

These mental health effects increase the risk of mental disorders, which is of concern given that these immigrants have limited access to health care, including mental health services, Garcini says.

The field of psychology needs to further study and address the impact of potentially traumatic events in this immigrant community, including the uncertainty surrounding DACA, Garcini and her coauthors write.

“Advocacy efforts to improve immigration policies need to be strengthened to combat the harmful mental and physical health impacts of the potential termination of DACA and those affected by it,” Garcini says.

Additional coauthors are from the University of Georgia, Yale University, Utah State University, the University of Texas Rio Grande Valley, and Rutgers University.

Source: Rice University

A research review proposes a “more realistic” conceptual model for understanding current and future changes to marine ecosystems in the wake of climate change.

The new approach to examining the effects of climate change on marine ecosystems may provide a more accurate understanding of climate change responses—and predictions for future consequences—according to the paper.

Published in the Annual Review of Ecology, Evolution, and Systematics, the paper highlights the interplay between the trend of climate warming and the fluctuations in local temperature. These two properties cause atypically warm events such as marine heatwaves to occur with increasing frequency and magnitude.

However, the interaction between the steadily warming climate and the spikes in local temperatures tends to be underappreciated, according to study coauthor Jon Witman, a professor of biology at Brown University.

“Climate change studies often focus on the trend of global warming,” Witman says. “But organisms in the ocean are also experiencing temperature fluctuations, and that’s less studied and therefore less understood. What we’re trying to do is to add more reality into ocean climate change studies by considering both the smooth, upward trend of climate warming as well as the variability on top of that trend.”

The paper proposes a new approach for understanding and modeling the effects of marine climate change, with suggestions for future research.

Witman offered coral as an example that illustrates the need for a new approach. While an organism like coral is already trying to adapt to the trend of rising temperatures, he notes, it then endures a heat wave, which causes a large and sudden spike in temperature.

Temperature spikes tend to lead to coral bleaching, which is when metabolically stressed corals expel the beneficial microscopic algae living within them and turn white. If the temperature stays high and algae are unable to return to their host coral, the bleached coral will die.

Witman points to heat waves in the Mediterranean that have led to an increase in coral bleaching and death of corals and sea fans.

Extreme events such as heat waves may alter or damage marine ecosystems in ways that leave them more vulnerable to both progressive climate change as well as the next temperature fluctuation, Witman adds. A more realistic model may help scientists better identify areas where coral is more likely to die off in an extreme event leaving coral-dependent organisms at risk over time, he says.

In other cases, temperature variability can lead to an opposite response in the affected organism: an ability to acclimatize or adapt to temperature extremes, depending on their frequency and intensity.

These responses to variable events like heat waves compound and are compounded by the effects caused by rapidly and steadily increasing ocean temperatures, Witman says.

Witman collaborated with Andrew Pershing of the nonprofit Climate Central and John Bruno, a professor of biology in the University of North Carolina at Chapel Hill.

In their paper, Bruno, Pershing, and Witman considered how organisms and communities adapt or adjust to both smooth trends and variable changes, and then reviewed processes that influence the rate at which marine communities adjust to changes in their physical environment—as well as those processes that might hamper adaption or acclimatization. The researchers stressed that all of these factors illustrate why it’s key to consider both types of change when studying marine climates.

“If we just study how organisms respond to the smooth trend, we miss all the variability, which is driving ecological change,” Witman says. “It’s not just a matter of worsening physiological stress over time; there are also variable events that have their own ripple effects.”

In the paper, the researchers created a global model that shows the variability in temperature relative to trend, highlighting regions where extreme temperatures are likely to have particularly deleterious effects. In the areas of the Gulf of Maine, the Caribbean Sea, and the Mediterranean Sea, they write, there are high probabilities of exceptional warming events and “ecological surprises.” Research shows that key foundation species in these regions, such kelp and corals, have already experienced substantial climate-related changes.

“These areas, especially, warrant investigation to improve our understanding of what’s going to happen in the future—as well as our conception of what we’re calling, ‘the new ocean,’” Witman says.

This work has support from the National Science Foundation, Biological Oceanography Program.

Source: Brown University

Nanoplastics interact with a particular protein that is naturally found in the brain, creating changes linked to Parkinson’s disease and some types of dementia, a new study shows.

As reported in the journal Science Advances, the findings create a foundation for a new area of investigation, fueled by the timely impact of environmental factors on human biology.

“Parkinson’s disease has been called the fastest growing neurological disorder in the world,” says principal investigator Andrew West, professor in the pharmacology and cancer biology department at Duke University School of Medicine. “Numerous lines of data suggest environmental factors might play a prominent role in Parkinson’s disease, but such factors have for the most part not been identified.”

Improperly disposed plastics have been shown to break into very small pieces and accumulate in water and food supplies, and were found in the blood of most adults in a recent study.

“Our study suggests that the emergence of micro and nanoplastics in the environment might represent a new toxin challenge with respect to Parkinson’s disease risk and progression,” West says. “This is especially concerning given the predicted increase in concentrations of these contaminants in our water and food supplies.”

West and colleagues found that nanoparticles of the plastic polystyrene—typically found in single use items such as disposable drinking cups and cutlery—attract the accumulation of the protein known as alpha-synuclein.

The study’s most surprising findings, West says, are the tight bonds formed between the plastic and the protein within the area of the neuron where these accumulations are congregating, the lysosome.

Researchers say the plastic-protein accumulations happened across three different models performed in the study—in test tubes, cultured neurons, and mouse models of Parkinson’s disease.

West says questions remain about how such interactions might be happening within humans and whether the type of plastic might play a role.

“While microplastic and nanoplastic contaminants are being closely evaluated for their potential impact in cancer and autoimmune diseases, the striking nature of the interactions we could observe in our models suggest a need for evaluating increasing nanoplastic contaminants on Parkinson’s disease and dementia risk and progression,” West says.

“The technology needed to monitor nanoplastics is still at the earliest possible stages and not ready yet to answer all the questions we have,” he says.

“But hopefully efforts in this area will increase rapidly, as we see what these particles can do in our models. If we know what to look out for, we can take the necessary steps to protect ourselves, without compromising all the benefits we reap every day from plastics.”

Additional coauthors are from Duke and Trinity College of Arts and Sciences. The Michael J. Fox Foundation for Parkinson’s Research and the Aligning Science Across Parkinson’s initiative funded the work.

Source: Duke University