BOSTON — Some aspects of speech are as Southern as pecan pie. Consider the vowel shift that makes the word pie sound more like “pah.” While that pronunciation is found from Florida to Texas, a new study reveals a surprising diversity in Southern vowel pronunciation that’s linked to a speaker’s age, social class, gender, race and geography.

The research, presented June 29 at a meeting of the Acoustical Society of America, could help software developers create better speech recognition tools for smartphones and other devices.
To understand the medley of southern vowel sounds, linguist Margaret Renwick of the University of Georgia in Athens dove into the Digital Archive of Southern Speech. The archive comprises almost 400 hours of interviews with 64 native Southerners representing a mix of ethnicities, social classes, education levels and ages.

Renwick’s analysis of more than 300,000 vowel sounds finds, for example, that Southern upper middle class women are often at the extreme end of variation in pronunciation. While Southern men and women are equally likely to shift the vowel in bet to “bay-ut,” upper middle class Southern women are more likely to stretch the vowel sound in bit to “bee-ut.” They are also most likely to pronounce bait as bite. The finding that women are more inclined to draw a sound out into two syllables — or change it entirely — is in line with other research suggesting that women are linguistic innovators, and less likely to adhere to the norms of standard American English, Renwick said.

For a glue that holds up inside the body, turn to the humble slug, Arion subfuscus. A new super-sticky material mimics slug slime’s ability to stick on slick wet surfaces and could lead to more effective medical adhesives.

The material has two parts: a sticky layer that attaches to a surface, and a shock-absorbing layer that reduces strain. That makes the adhesive less likely to snap off.

Researchers tested the material as a surgical adhesive in a number of different scenarios: It stuck to pig skin and liver. It latched on to a beating pig’s heart, even when the surface was coated in blood. It sealed up a heart defect, preventing liquid from leaking even when the organ was inflated and deflated tens of thousands of times. And it was less toxic in the body than a commonly used commercialized tissue adhesive, researchers report July 28 in Science.

The researchers hope the material could someday be used in surgical procedures in place of invasive sutures and staples.

Famously sneaky particles have been caught behaving in a new way.

For the first time, scientists have detected neutrinos scattering off the nucleus of an atom. The process, predicted more than four decades ago, provides a new way to test fundamental physics. It will also help scientists to better characterize the neutrino, a misfit particle that has a tiny mass and interacts so feebly with matter that it can easily sail through the entire Earth.
The detection, reported online August 3 in Science, “has really big implications,” says physicist Janet Conrad of MIT, who was not involved with the research. It fills in a missing piece of the standard model, the theory that explains how particles behave: The model predicts that neutrinos interact with nuclei. And, says Conrad, the discovery “opens up a whole new area of measurements” to further test the standard model’s predictions.

Scientists typically spot neutrinos when they interact with a single proton or neutron. But the new study measures “coherent” scattering, in which a low-energy neutrino interacts with an entire atomic nucleus at once, ricocheting away and causing the nucleus to recoil slightly in response.

“It’s exciting to measure it for the first time,” says physicist Kate Scholberg of Duke University, spokesperson for the collaboration — named COHERENT — that made the new finding.

In the past, neutrino hunters have built enormous detectors to boost their chances of catching a glimpse of the particles — a necessity because the aloof particles interact so rarely. While still rare, coherent neutrino scattering occurs more often than previously detected types of neutrino interactions. That means detectors can be smaller and still catch enough interactions to detect the process. COHERENT’s detector, a crystal of cesium and iodine, weighs only about 15 kilograms. “It’s the first handheld neutrino detector; you can just carry it around,” says physicist Juan Collar of the University of Chicago.

Collar, Scholberg and colleagues installed their detector at the Spallation Neutron Source at Oak Ridge National Laboratory in Tennessee. The facility generates bursts of neutrons and, as a by-product, produces neutrinos at energies that COHERENT’s detector can spot. When a nucleus in the crystal recoils due to a scattering neutrino, a flash of light appears and is captured by a light sensor. The signal of the recoiling nucleus is incredibly subtle — like detecting the motion of a bowling ball when hit by a ping-pong ball — which is why the effect remained undetected until now.
The amount of scattering the researchers saw agreed with the standard model. But such tests are still in their early stages, says physicist Leo Stodolsky of the Max Planck Institute for Physics in Munich, who was not involved with the research. “We’re looking forward to more detailed studies to see if it really is accurately in agreement with the expectations.” Physicists hope to find a place where the standard model breaks down, which could reveal new secrets of the universe. More precise tests may reveal discrepancies, he says. “That would be extremely interesting.”

Measuring coherent neutrino scattering could help scientists understand the processes that occur within exploding stars, or supernovas, which emit huge numbers of neutrinos (SN: 02/18/17, p. 24). The process could be used to detect supernovas as well — if a supernova explodes nearby, scientists could spot its neutrinos scattering off nuclei in their detectors.

Similar scattering might also help scientists detect dark matter, an invisible source of mass that pervades the universe. Dark matter particles could scatter off atomic nuclei just as neutrinos do, causing a recoil. The study indicates that such recoils are detectable — good news since several dark matter experiments are currently attempting to measure recoils of nuclei (SN: 11/12/16, p. 14). But it also suggests a looming problem: As dark matter detectors become more sensitive, neutrinos bouncing off the nuclei will swamp any signs of dark matter.

Coherent neutrino scattering detectors could lead to practical applications as well: Small-scale neutrino detectors could eventually detect neutrinos produced in nuclear reactors to monitor for attempts to develop nuclear weapons, for example.

Physicist Daniel Freedman of MIT, who predicted in 1974 that neutrinos would scatter off nuclei, is pleased that his prediction has finally been confirmed. “It’s a thrill.”

The 2011 tsunami that devastated Japan’s coast cast an enormous amount of debris out to sea — way out. Japanese marine life took advantage of the new floating real estate and booked a one-way trip to America. From 2012 to 2017, at least 289 living Japanese marine species washed up on the shores of North America and Hawaii, hitching rides on fishing boats, docks, buoys, crates and other nonbiodegradable objects, a team of U.S. researchers report in the Sept. 29 Science.

Organisms that surprisingly survived the harsh 7,000-kilometer journey across the Pacific Ocean on 634 items of tsunami debris ranged from 52-centimeter-long fish (a Western Pacific yellowtail amberjack) to microscopic single-celled protists. About 65 percent of the species have never been seen in North America’s Pacific waters. If these newcomers become established, they have the potential to become invasive, disrupting native marine habitats, says study coauthor James Carlton, a marine scientist at Williams College in Mystic, Conn.
Meet some of the slimiest, strangest and potentially most invasive marine castaways that took this incredible journey:

The Northern Pacific sea star (Asterias amurensis) is among the world’s most invasive species. Though this purple and yellow sea star is normally found in shallow habitats, it can live as deep as 200 meters.

Skeleton shrimp (Caprella cristibrachium and C. mutica (shown)) grasp onto algae with their strong rear claws, earning them the nickname “praying mantis of the sea.” These lanky amphipods can grow up to about 5 centimeters long and are found in the Sea of Japan.
A white, brittle Bryozoan (Biflustra grandicella) that can grow as big as a basketball is already invasive in Australia. The tiny swimming larvae of these sea creatures, also known as moss animals, may live up to a week, long enough to settle in to a new habitat.

Most of the wooden Japanese debris items collected carried at least one of seven species of large wormlike mollusks called Japanese shipworms (Psiloteredo sp.). Some of the more monstrous shipworms found, which bore into everything from wooden pilings to docks, had grown to about 50 centimeters long.
Five Japanese barred knifejaw fish (Oplegnathus fasciatus), also known as striped beakfish, were found trapped in the stern well of a Japanese fishing boat found beached in 2013 in Washington. These black-and-white striped fish are native to the Northwest Pacific Ocean and Hawaii. The well acted as a tide pool of sorts, sustaining the fish during their two-year journey.

The wavy-shelled slipper snail (Crepidula onyx), also known as a slipper limpet, has essentially come full circle in its journey around the Pacific Ocean. Native to the U.S. West Coast, the well-traveled snail became an invasive species in Japan, and now has returned to America on Japanese debris.

Campfire legends of massive, shaggy bipeds called yetis are grounded in a less mysterious truth: bears.

Eight samples of remains such as fur, bones and teeth purportedly from mountain-dwelling yetis actually come from three different kinds of bears that live in the Himalayas, researchers report November 29 in the Proceedings of the Royal Society B. A ninth sample turned out to come from a dog.

Previous analyses of smaller fragments of “yeti” DNA yielded controversial results. The new study looks at bigger chunks of DNA, analyzing the complete mitochondrial genomes from alleged yetis and comparing them with the mitochondrial genomes of various bears, including polar bears and Tibetan brown bears.
The results also give new insight into the genetic relationships between the different bears that call the Tibetan Plateau home, which could guide efforts to protect these rare subspecies. During a period of glaciation about 660,000 years ago, Himalayan brown bears were one of the first groups to branch off and become distinct from other brown bears, the data suggest.

Tibetan brown bears, on the other hand, share a more recent common ancestor with their relatives in Eurasia and North America. They might have migrated to the area around 340,000 years ago, but were probably kept geographically isolated from Himalayan brown bears by the rugged mountain terrain.

COLLEGE PARK, Md. — Campus life typically challenges students with new opportunities for learning, discovery — and intimacy with germs. Lots of germs.

That makes dormitories and their residents an ideal natural experiment to trace the germs’ paths. “You pack a bunch of college kids into a very small environment … we’re not known as being the cleanliest of people,” says sophomore Parker Kleb at the University of Maryland in College Park. Kleb is a research assistant for an ongoing study tracking the spread of respiratory viruses through a student population. The study’s goal is to better understand how these viruses move around, in order to help keep illness at bay — all the more pressing, as the current flu season is on track to be among the worst recorded in the United States.
Called “C.A.T.C.H. the Virus,” which stands for Characterizing and Tracking College Health, the study traces the trajectory of viral infections using blood samples, nasal swabs and breath samples from ailing freshmen and their closest contacts. (Tagline: It’s snot your average research study.)

Donald Milton, an environmental and occupational health physician-scientist, heads the project. On a recent day, he described the study to a classroom of freshmen he hopes to recruit. He ticked off questions this research seeks to answer: What is it that makes people susceptible to getting sick? What makes them contagious? And how do they transmit a virus to others? “Maybe your house, your room has something to do with whether you’re at risk of getting infected,” Milton said.

He had a receptive audience: members of the College Park Scholars’ Global Public Health program. Infection control is right up their alley. “How sick do we have to be?” one student asked. It’s the culprit that matters, she’s told. The study covers acute respiratory infections due to influenza viruses, adenoviruses, coronaviruses or respiratory syncytial virus, known as RSV.

Of most interest, however, is influenza. “Flu is important to everybody,” says Milton. Influenza is thought to spread among humans three ways — touch; coughing and sneezing, which launches droplets containing virus from the lungs onto surfaces; and aerosols, smaller droplets suspended in the air that could be inhaled (SN: 6/29/13, p. 9).
How much each of these modes of transmission contributes to the spread of viruses is a point of fierce debate, Milton says. And that makes infection control difficult, especially in hospitals. “If we don’t understand how [viruses] are transmitted, it’s hard to come up with policies that are really going to work.”
Milton and his colleagues recently reported that people with the flu can shed infectious virus particles just by breathing. Of 134 fine-aerosol samples taken when patients were breathing normally, 52 contained infectious influenza virus — or 39 percent, according to the study, published online January 18 in the Proceedings of the National Academy of Sciences . Those fine-aerosol particles of respiratory tract fluid are 5 microns in diameter or less, small enough to stay suspended in the air and potentially contribute to airborne transmission of the flu, the researchers say.
“This could mean that just having good cough and sneeze etiquette — sneezing or coughing into tissues — may not be enough to limit the spread of influenza,” says virologist Andrew Pekosz at Johns Hopkins University, who was not involved with the study. “Just sitting in your office and breathing could fill the air with infectious influenza.”

The C.A.T.C.H. study aims to find out if what’s in the air is catching. In two University of Maryland dorms, carbon dioxide sensors measure how much of the air comes from people’s exhalations. In addition, laboratory tests measure how much virus sick students are shedding into the air. To get those samples, students sit in a ticket booth‒sized contraption called the Gesundheit-II and breathe into a giant cone. These data can help researchers estimate students’ airborne exposure to viruses, Milton says.

Another key dataset comes from DNA testing of the viruses infecting the students. “The virus mutates reasonably fast,” Milton says, so the more people it’s moved through, the more changes it will have. By combining this molecular chain of transmission with the social chain of transmission, the researchers will try to “establish who infected whom, and where, and how,” Milton says.

The goal is to enroll 130 students in C.A.T.C.H. It’s doubtful they’ll all get sick, but not that many students from this initial group are needed to start the ball rolling, says Jennifer German, a virologist and C.A.T.C.H. student engagement coordinator. “For every index case that has an infection we’re interested in, we’re following four additional contacts,” she says. “And then if any of those contacts becomes sick, we’ll get their contacts and so on.”

The study began in November 2017. As of the end of January, German says, researchers have collected samples from five sick students, but only one was infected with a target virus, influenza. The researchers now are following three contacts from that case.

But timing and the size of the current flu outbreak may be on the researchers’ side. Kleb, the research assistant, says that students are still waiting for this season’s flu to sweep through the dorms. “Once one person gets sick, it goes around to everyone on the floor,” he says. “I’m very interested to see what happens in the next few weeks, and how the study will hopefully benefit.”

Tiny particles of plastic have been found everywhere — from the deepest place on the planet, the Mariana Trench, to the top of Mount Everest. And now more and more studies are finding that microplastics, defined as plastic pieces less than 5 millimeters across, are also in our bodies.

“What we are looking at is the biggest oil spill ever,” says Maria Westerbos, founder of the Plastic Soup Foundation, an Amsterdam-based nonprofit advocacy organization that works to reduce plastic pollution around the world. Nearly all plastics are made from fossil fuel sources. And microplastics are “everywhere,” she adds, “even in our bodies.”
In recent years, microplastics have been documented in all parts of the human lung, in maternal and fetal placental tissues, in human breast milk and in human blood. Microplastics scientist Heather Leslie, formerly of Vrije Universiteit Amsterdam, and colleagues found microplastics in blood samples from 17 of 22 healthy adult volunteers in the Netherlands. The finding, published last year in Environment International, confirms what many scientists have long suspected: These tiny bits can get absorbed into the human bloodstream.

“We went from expecting plastic particles to be absorbable and present in the human bloodstream to knowing that they are,” Leslie says.
The findings aren’t entirely surprising; plastics are all around us. Durable, versatile and cheap to manufacture, they are in our clothes, cosmetics, electronics, tires, packaging and so many more items of daily use. And the types of plastic materials on the market continues to increase. “There were around 3,000 [plastic materials] when I started researching microplastics over a decade ago,” Leslie says. “Now there are over 9,600. That’s a huge number, each with its own chemical makeup and potential toxicity.”

Though durable, plastics do degrade, by weathering from water, wind, sunlight or heat — as in ocean environments or in landfills — or by friction, in the case of car tires, which releases plastic particles along roadways during motion and braking.

In addition to studying microplastic particles, researchers are also trying to get a handle on nanoplastics, particles which are less than 1 micrometer in length. “The large plastic objects in the environment will break down into micro- and nanoplastics, constantly raising particle numbers,” says toxicologist Dick Vethaak of the Institute for Risk Assessment Sciences at Utrecht University in the Netherlands, who collaborated with Leslie on the study finding microplastics in human blood.

Nearly two decades ago, marine biologists began drawing attention to the accumulation of microplastics in the ocean and their potential to interfere with organism and ecosystem health (SN: 2/20/16, p. 20). But only in recent years have scientists started focusing on microplastics in people’s food and drinking water — as well as in indoor air.

Plastic particles are also intentionally added to cosmetics like lipstick, lip gloss and eye makeup to improve their feel and finish, and to personal care products, such as face scrubs, toothpastes and shower gels, for the cleansing and exfoliating properties. When washed off, these microplastics enter the sewage system. They can end up in the sewage sludge from wastewater treatment plants, which is used to fertilize agricultural lands, or even in treated water released into waterways.

What if any damage microplastics may do when they get into our bodies is not clear, but a growing community of researchers investigating these questions thinks there is reason for concern. Inhaled particles might irritate and damage the lungs, akin to the damage caused by other particulate matter. And although the composition of plastic particles varies, some contain chemicals that are known to interfere with the body’s hormones.

Currently there are huge knowledge gaps in our understanding of how these particles are processed by the human body.

How do microplastics get into our bodies?
Research points to two main entry routes into the human body: We swallow them and we breathe them in.

Evidence is growing that our food and water is contaminated with microplastics. A study in Italy, reported in 2020, found microplastics in everyday fruits and vegetables. Wheat and lettuce plants have been observed taking up microplastic particles in the lab; uptake from soil containing the particles is probably how they get into our produce in the first place.

Sewage sludge can contain microplastics not only from personal care products, but also from washing machines. One study looking at sludge from a wastewater treatment plant in southwest England found that if all the treated sludge produced there were used to fertilize soils, a volume of microplastic particles equivalent to what is found in more than 20,000 plastic credit cards could potentially be released into the environment each month.

On top of that, fertilizers are coated with plastic for controlled release, plastic mulch film is used as a protective layer for crops and water containing microplastics is used for irrigation, says Sophie Vonk, a researcher at the Plastic Soup Foundation.

“Agricultural fields in Europe and North America are estimated to receive far higher quantities of microplastics than global oceans,” Vonk says.
A recent pilot study commissioned by the Plastic Soup Foundation found microplastics in all blood samples collected from pigs and cows on Dutch farms, showing livestock are capable of absorbing some of the plastic particles from their feed, water or air. Of the beef and pork samples collected from farms and supermarkets as part of the same study, 75 percent showed the presence of microplastics. Multiple studies document that microplastic particles are also in fish muscle, not just the gut, and so are likely to be consumed when people eat seafood.

Microplastics are in our drinking water, whether it’s from the tap or bottled. The particles may enter the water at the source, during treatment and distribution, or, in the case of bottled water, from its packaging.

Results from studies attempting to quantify levels of human ingestion vary dramatically, but they suggest people might be consuming on the order of tens of thousands of microplastic particles per person per year. These estimates may change as more data come in, and they will likely vary depending on people’s diets and where they live. Plus, it is not yet clear how these particles are absorbed, distributed, metabolized and excreted by the human body, and if not excreted immediately, how long they might stick around.

Babies might face particularly high exposures. A small study of six infants and 10 adults found that the infants had more microplastic particles in their feces than the adults did. Research suggests microplastics can enter the fetus via the placenta, and babies could also ingest the particles via breast milk. The use of plastic feeding bottles and teething toys adds to children’s microplastics exposure.

Microplastic particles are also floating in the air. Research conducted in Paris to document microplastic levels in indoor air found concentrations ranging from three to 15 particles per cubic meter of air. Outdoor concentrations were much lower.

Airborne particles may turn out to be more of a concern than those in food. One study reported in 2018 compared the amount of microplastics present within mussels harvested off Scotland’s coasts with the amount of microplastics present in indoor air. Exposure to microplastic fibers from the air during the meal was far higher than the risk of ingesting microplastics from the mussels themselves.

Extrapolating from this research, immunologist Nienke Vrisekoop of the University Medical Center Utrecht says, “If I keep a piece of fish on the table for an hour, it has probably gathered more microplastics from the ambient air than it has from the ocean.”
What’s more, a study of human lung tissue reported last year offers solid evidence that we are breathing in plastic particles. Microplastics showed up in 11 of 13 samples, including those from the upper, middle and lower lobes, researchers in England reported.

Perhaps good news: Microplastics seem unable to penetrate the skin. “The epidermis holds off quite a lot of stuff from the outside world, including [nano]particles,” Leslie says. “Particles can go deep into your skin, but so far we haven’t observed them passing the barrier, unless the skin is damaged.”

What do we know about the potential health risks?
Studies in mice suggest microplastics are not benign. Research in these test animals shows that lab exposure to microplastics can disrupt the gut microbiome, lead to inflammation, lower sperm quality and testosterone levels, and negatively affect learning and memory.

But some of these studies used concentrations that may not be relevant to real-world scenarios. Studies on the health effects of exposure in humans are just getting under way, so it could be years before scientists understand the actual impact in people.

Immunologist Barbro Melgert of the University of Groningen in the Netherlands has studied the effects of nylon microfibers on human tissue grown to resemble lungs. Exposure to nylon fibers reduced both the number and size of airways that formed in these tissues by 67 percent and 50 percent, respectively. “We found that the cause was not the microfibers themselves but rather the chemicals released from them,” Melgert says.

“Microplastics could be considered a form of air pollution,” she says. “We know air pollution particles tend to induce stress in our lungs, and it will probably be the same for microplastics.”

Vrisekoop is studying how the human immune system responds to microplastics. Her unpublished lab experiments suggest immune cells don’t recognize microplastic particles unless they have blood proteins, viruses, bacteria or other contaminants attached. But it is likely that such bits will attach to microplastic particles out in the environment and inside the body.

“If the microplastics are not clean … the immune cells [engulf] the particle and die faster because of it,” Vrisekoop says. “More immune cells then rush in.” This marks the start of an immune response to the particle, which could potentially trigger a strong inflammatory reaction or possibly aggravate existing inflammatory diseases of the lungs or gastrointestinal tract.
Some of the chemicals added to make plastic suitable for particular uses are also known to cause problems for humans: Bisphenol A, or BPA, is used to harden plastic and is a known endocrine disruptor that has been linked to developmental effects in children and problems with reproductive systems and metabolism in adults (SN: 7/18/09, p. 5). Phthalates, used to make plastic soft and flexible, are associated with adverse effects on fetal development and reproductive problems in adults along with insulin resistance and obesity. And flame retardants that make electronics less flammable are associated with endocrine, reproductive and behavioral effects.

“Some of these chemical products that I worked on in the past [like the polybrominated diphenyl ethers used as flame retardants] have been phased out or are prohibited to use in new products now [in the European Union and the United States] because of their neurotoxic or disrupting effects,” Leslie says.
What are the open questions?
The first step in determining the risk of microplastics to human health is to better understand and quantify human exposure. Polyrisk — one of five large-scale research projects under CUSP, a multidisciplinary group of researchers and experts from 75 organizations across 21 European countries studying micro- and nanoplastics — is doing exactly that.

Immunotoxicologist Raymond Pieters, of the Institute for Risk Assessment Sciences at Utrecht University and coordinator of Polyrisk, and colleagues are studying people’s inhalation exposure in a number of real-life scenarios: near a traffic light, for example, where cars are likely to be braking, versus a highway, where vehicles are continuously moving. Other scenarios under study include an indoor sports stadium, as well as occupational scenarios like the textile and rubber industry.

Melgert wants to know how much microplastic is in our houses, what the particle sizes are and how much we breathe in. “There are very few studies looking at indoor levels [of microplastics],” she says. “We all have stuff in our houses — carpets, insulation made of plastic materials, curtains, clothes — that all give off fibers.”

Vethaak, who co-coordinates MOMENTUM, a consortium of 27 research and industry partners from the Netherlands and seven other countries studying microplastics’ potential effects on human health, is quick to point out that “any measurement of the degree of exposure to plastic particles is likely an underestimation.” In addition to research on the impact of microplastics, the group is also looking at nanoplastics. Studying and analyzing these smallest of plastics in the environment and in our bodies is extremely challenging. “The analytical tools and techniques required for this are still being developed,” Vethaak says.

Vethaak also wants to understand whether microplastic particles coated with bacteria and viruses found in the environment could spread these pathogens and increase infection rates in people. Studies have suggested that microplastics in the ocean can serve as safe havens for germs.

Alongside knowing people’s level of exposure to microplastics, the second big question scientists want to understand is what if any level of real-world exposure is harmful. “This work is confounded by the multitude of different plastic particle types, given their variations in size, shape and chemical composition, which can affect uptake and toxicity,” Leslie says. “In the case of microplastics, it will take several more years to determine what the threshold dose for toxicity is.”

Several countries have banned the use of microbeads in specific categories of products, including rinse-off cosmetics and toothpastes. But there are no regulations or policies anywhere in the world that address the release or concentrations of other microplastics — and there are very few consistent monitoring efforts. California has recently taken a step toward monitoring by approving the world’s first requirements for testing microplastics in drinking water sources. The testing will happen over the next several years.

Pieters is very pragmatic in his outlook: “We know ‘a’ and ‘b,’” he says. “So we can expect ‘c,’ and ‘c’ would [imply] a risk for human health.”

He is inclined to find ways to protect people now even if there is limited or uncertain scientific knowledge. “Why not take a stand for the precautionary principle?” he asks.

For people who want to follow Pieters’ lead, there are ways to reduce exposure.

“Ventilate, ventilate, ventilate,” Melgert says. She recommends not only proper ventilation, including opening your windows at home, but also regular vacuum cleaning and air purification. That can remove dust, which often contains microplastics, from surfaces and the air.

Consumers can also choose to avoid cosmetics and personal care products containing microbeads. Buying clothes made from natural fabrics like cotton, linen and hemp, instead of from synthetic materials like acrylic and polyester, helps reduce the shedding of microplastics during wear and during the washing process.

Specialized microplastics-removal devices, including laundry balls, laundry bags and filters that attach to washing machines, are designed to reduce the number of microfibers making it into waterways.

Vethaak recommends not heating plastic containers in the microwave, even if they claim to be food grade, and not leaving plastic water bottles in the sun.

Perhaps the biggest thing people can do is rely on plastics less. Reducing overall consumption will reduce plastic pollution, and so reduce microplastics sloughing into the air and water.

Leslie recommends functional substitution: “Before you purchase something, think if you really need it, and if it needs to be plastic.”

Westerbos remains hopeful that researchers and scientists from around the world can come together to find a solution. “We need all the brainpower we have to connect and work together to find a substitute to plastic that is not toxic and doesn’t last [in the environment] as long as plastic does,” she says.

A thick sphere of icy debris known as the Oort cloud shrouds the solar system. Other star systems may harbor similar icy reservoirs, and those clouds may be visible in the universe’s oldest light, researchers report.

Astronomer Eric Baxter of the University of Pennsylvania and colleagues looked for evidence of such exo-Oort clouds in maps of the cosmic microwave background, the cool cosmic glow of the first light released after the Big Bang, roughly 13.8 billion years ago. No exo-Oort clouds have been spotted yet, but the technique looks promising, the team reports November 2 in the Astronomical Journal. Finding exo-Oort clouds could help shed light on how other solar systems — and perhaps even our own — formed and evolved.
The Oort cloud is thought to be a planetary graveyard stretching between about 1,000 and 100,000 times as far from the sun as Earth. Scientist think that this reservoir of trillions of icy objects formed early in the solar system’s history, when violent movements of the giant planets as they took shape tossed smaller objects outward. Every so often, one of those frozen planetary fossils dives back in toward the sun and is visible as a comet (SN: 11/16/13, p. 14).

But it’s difficult to observe the Oort cloud directly from within it. Despite a lot of circumstantial evidence for the Oort cloud’s existence, no one has ever seen it.

Ironically, exo-Oort clouds might be easier to spot, Baxter and colleagues thought. The objects in an exo-Oort cloud wouldn’t reflect enough starlight to be seen directly, but they would absorb starlight and radiate it back out into space as heat. For the sun’s Oort cloud, that heat signal would be smeared evenly across the entire sky from Earth’s perspective. But an exo-Oort cloud’s warmth would be limited to a tiny region around its star.

Baxter and colleagues calculated that the expected temperature of an exo-Oort cloud should be about –265° Celsius, or 10 kelvins. That’s right in range for experiments that detect the cosmic microwave background, or CMB, which is about 3 kelvins.
The team used data from the CMB-mapping Planck satellite to search for areas across the sky with the right temperature (SN Online: 7/24/18). Then, the researchers compared the results with the Gaia space telescope’s ultraprecise stellar map to see if those regions surrounded stars (SN: 5/26/18, p. 5).

Although the astronomers found some intriguing signals around several bright, nearby stars, it wasn’t enough to declare victory. “That’s pretty interesting, but we can’t definitively say that it’s from an Oort cloud or not,” Baxter says.

Other ongoing CMB experiments with higher resolution, like those with the South Pole Telescope and the Atacama Cosmology Telescope in the Chilean Andes, could confirm if those hints of exo-Oort clouds are real.

“It’s a super clever observational idea,” says astronomer Nicolas Cowan of McGill University in Montreal who was not involved in the new work. “Looking for exo-Oort clouds is looking for a signature of these violent histories in other solar systems.”

Cowan has suggested that the cosmic microwave background could also be used to search for a hypothetical Planet Nine in the sun’s Oort cloud (SN: 7/23/16, p. 7). “The very coolest thing would be if we could get measurements of the exo-Oort clouds and find planets in those systems,” he says.

A newly designed airplane prototype does away with noisy propellers and turbines.

Instead, it’s powered by ionic wind: charged molecules, or ions, flowing in one direction and pushing the plane in the other. That setup makes the aircraft nearly silent. Such stealth planes could be useful for monitoring environmental conditions or capturing aerial imagery without disturbing natural habitats below.

The aircraft is the first of its kind to be propelled in this way, researchers report in the Nov. 22 Nature. In 10 indoor test flights the small plane, which weighs about as much as a Chihuahua, traveled 40 to 45 meters for almost 10 seconds at a steady height, even gaining about half a meter of altitude over the course of a flight.
Most planes rely on spinning parts to move forward. In some, an engine turns a propeller that pushes the plane forward. Or a turbine sucks in air with a spinning fan, and then shoots out jets of gas that propel the plane forward.

Ionic wind is instead generated by a high-voltage electric field around a positively charged wire, called an emitter. The electricity, often supplied by batteries, makes electrons in the air collide with atoms and molecules, which then release other electrons. That creates a swarm of positively charged air molecules around the emitter, which are drawn to a negatively charged wire. The movement of molecules between the two wires, the ionic wind, can push a plane forward. The current design uses four sets of these wires.
Moving ions have helped other things to fly through the air, such as tiny airborne robots. But conventional wisdom said that using the approach to move something through the air as big as an airplane wasn’t possible, because adding enough battery power to propel a plane this way would make it too heavy to stay aloft. (The ion thrusters that propel spacecraft through the vacuum of space work in a very different way and aren’t functional in air.) Attempts to build ion-propelled aircraft in the 1960s weren’t very successful.
MIT aeronautics researcher Steven Barrett thought differently. With the right aircraft design and light enough batteries, flight might be possible, his initial calculations suggested. So he and his team used mathematical equations to optimize various features of the airplane — its shape, materials, power supply — and to predict how each version would fly. Then the researchers built prototypes of promising designs and tested the planes at the MIT indoor track, launching them via a bungee system.
“The models and the reality of construction don’t always match up perfectly,” Barrett says, so finding the right design took a lot of tries. But in the new study, he and his collaborators report success: 10 flights of the aircraft, which has a 5-meter wingspan and weighs just under 2.5 kilograms.

Barrett’s team isn’t the only one who thought the ionic wind method might take off. Based on calculations done in his lab, “we were confident that this could be done,” says Franck Plouraboue of the Toulouse Fluid Mechanics Institute in France, who wasn’t part of the research. “Here they’ve done it — which is fantastic!”

It’s an example of distributed electric propulsion, says Plouraboue — spreading out the thrust-generating parts of the plane, instead of having one centralized source. That’s a hot area for aircraft research right now. NASA’s X-57 Maxwell plane, for example, bears 14 battery-operated motors along its wings. Increasing the number of propellers makes the plane go farther on the same amount of energy, says Plouraboue, but also increases the drag. With ionic wind propulsion, increasing the number of wires doesn’t increase drag very much.

The plane still needs some upgrades before it’s ready for the real world: Its longest flight was only 12 seconds. And while the aircraft can maintain steady flight for a short time once launched, it can’t actually get off the ground using ionic wind.

Even with improvements, ion-propelled aircraft won’t find their niche as passenger planes, predicts Daniel Drew, an aerodynamics researcher at the University of California, Berkeley, who was not involved in the work. (Drew has designed miniature flying bots that fly using ionic propulsion.) It’s probably not feasible to scale up to something the size of a 747 — there are efficiency trade-offs as planes get bigger, he says. But down the road, the approach might be useful for small, uncrewed planes or drones.

From tales about whales to enthralling scientific histories and the memoir of a frustrated astrophysicist, 2018 was a banner year for science books. Here are Science News’ picks for the titles that should be on any science lover’s bookshelf. Find detailed reviews of many of these books in the links below and in our Editor’s Pick: Favorite books of 2018.

The Truth About Animals
Lucy Cooke

A zoologist debunks myths about bats, pandas, Adélie penguins and many other misunderstood creatures, recounting surprising stories from the animal kingdom (SN: 4/14/18, p. 26). Basic Books, $28

Spying On Whales
Nick Pyenson

In this captivating look at whales, a paleontologist dives into the animals’ past, exploring how some of Earth’s most intelligent species came to be, and their uncertain future (SN: 7/7/18, p. 29). Viking, $27

Eager
Ben Goldfarb

Some people see beavers as pests. But a science writer explains how the dam-building rodents are actually vital ecosystem engineers that can create or expand habitats that benefit the entire wildlife community (SN: 8/4/18, p. 28). Chelsea Green Publishing, $24.95

The Rise and Fall of the Dinosaurs
Steve Brusatte

In this memoir, a paleontologist blends experiences from his career with evolutionary science to take readers on an engrossing journey through time, from the beginnings of the dinosaurs to their ultimate extinction. William Morrow, $29.99

The Big Ones
Lucy Jones

A seismologist examines past catastrophic natural disasters, including volcanic eruptions, earthquakes and floods, and their impact on culture, politics and society (SN: 3/31/18, p. 26). With the past as a guide, the author warns readers to be prepared for when the next disaster strikes. Doubleday, $26.95

Losing the Nobel Prize
Brian Keating

An astrophysicist’s dream of winning a Nobel Prize turned to dust after a promising experiment failed to find the first definitive evidence of cosmic inflation. The experience revealed how the prize can hamper scientific progress (SN: 4/14/18, p. 27). W.W. Norton & Co., $27.95

The Poisoned City
Anna Clark

Weaving together history, science and reporting, a journalist explores the public health crisis that began in Flint, Mich., when lead started leaching into residents’ drinking water (SN: 7/21/18, p. 28). Metropolitan Books, $30

The Poison Squad
Deborah Blum

A Pulitzer Prize–winning journalist tells the story of a government chemist at the turn of the 20th century and his mission to make food safe in the United States. Penguin Press, $28

Aroused
Randi Hutter Epstein

The history of endocrinology makes for a strange and fascinating read, from the scientists who discovered the effects of hormones to the people whose lives have been irrevocably changed by these powerful substances (SN: 7/7/18, p. 28). W.W. Norton & Co., $26.95

Nine Pints
Rose George

Blood, the feared as well as revered substance that flows throughout the human body, has a rich historical and scientific past (SN: 10/27/18, p. 28). Metropolitan Books, $30

She Has Her Mother’s Laugh
Carl Zimmer

This comprehensive history recounts how researchers have come to understand genetic inheritance. Looking to the future, the author considers risks of gene manipulation (SN: 6/9/18, p. 29). Dutton, $30

Genetics in the Madhouse
Theodore M. Porter

Using archival records, a science historian traces the origins of the study of human heredity to insane asylums in the 1800s (SN: 7/7/18, p. 29). Princeton Univ., $35

The Tangled Tree
David Quammen

In chronicling the lives of researchers who made important advances in molecular biology and genetics, this book shows how recent findings shake up our understanding of evolution and the tree of life. Simon & Schuster, $30