A healthy oral microbiome, a community of microorganisms live in the mouth, plays an important role in aiding in the digestion of food, immune system support and protecting against invading pathogens, while an unhealthy oral microbiome has been linked to a variety of diseases in humans.

“The oral microbiome has been understudied, and most studies of the oral microbiome have been conducted in Western populations,” said Emily Davenport, assistant professor of biology in the Penn State Eberly College of Science and leader of the research team. “Although we have learned a lot from that, microbiomes look different around the world. By studying how the diversity and composition of the oral microbiome varies with lifestyle in a global context, we can improve our knowledge of how the oral microbiome impacts human health.”

In a study of 63 Nepali individuals representing spectrum of dietary practices, the researchers examined how major lifestyle factors like subsistence strategy — how a person obtains the necessities of life like food and shelter — as well as more specific factors and behaviors, like smoking, may be contributing to differences in the microbiomes across populations.

“We know from previous studies that there are differences in the microbiome between individuals that live in highly industrialized, Westernized societies and those that are nomadic hunter gatherers, but there is a broad spectrum of lifestyles between those,” said Erica Ryu, graduate student in biology in the Penn State Eberly College of Science and first author of the paper. “Our understanding of these relationships so far has been clouded by geography; it’s difficult to make statements about the impact of lifestyles when you are comparing people in different countries with, for example, different climates, access to medical care, and exposure to diseases. In this study, we comprehensively investigated the oral microbiome of individuals across a range of lifestyles from the same country, Nepal.”

The researchers studied the oral microbiomes of people from groups with a variety of subsistence strategies. These included foragers, who are hunters and gatherers and may not live in one location for the entire year; subsistence farmers who are hunter gatherers from groups that recently settled and began farming in the past 50 years; agriculturalists from groups that have relied on farming for several centuries; industrialists, who are expatriates from Nepal that immigrated to the United States within the last 20 years; as well as a group of industrialists who were born in the same area of the United States for comparison. They also asked a variety of questions about lifestyle, including diet, education, medical practices, and other behaviors.

The researchers sequenced the DNA of the microbes within saliva samples to determine the specific species of bacteria within each individual’s oral microbiome. They found that the composition of species within the oral microbiome tended to follow the gradient of subsistence strategies, with some specific species more prominent in foragers and one species more prominent in the industrialists, suggesting that lifestyle does indeed impact the oral microbiome.

Additionally, the presence of several species of microbes were related to specific lifestyle factors, including smoking, the prominent type of grains in an individual’s diet — barley and maize vs. rice and wheat — and consumption of a plant called nettle. The researchers note that previous research has associated consistent smoking with oral microbiome composition in industrialized populations, and collectively this suggests that smoking habits play an important role in determining the oral microbiome across a variety of lifestyles.

“It makes sense that different microbes might feed on the different grains in a person’s diet, but it’s interesting that we also see an association with sisnu, also called nettle,” Davenport said. “Nettle is a fibrous plant often chewed by the foragers in this study, much like people might chew gum. Given its important role in Nepali cuisine, culture and medicine, it’s interesting to see it is associated with oral microbes.”

The researchers stressed the importance of including lifestyle factors and behaviors in future microbiome studies as well as including populations from around the world.

“We studied populations in Nepal because it offered a unique way to explore the effects of lifestyle while controlling for a variety of other factors like geography that often obscure that effect,” Davenport said. “But it highlights the impact of lifestyle factors that likely play a role in other populations.

“Whenever you make a shift — whether it’s to a different diet or different location or different culture — the microbiome can change too, and it’s important to understand to what extent and how quickly these changes occur,” she added. “Continuing to investigate how oral microbiomes vary across the globe will help improve our understanding of what exactly shapes the microbiome and how that impacts human health.”

In addition to Davenport and Ryu, the research team at Penn State includes Meera Gupta, undergraduate student at the time of the research. The team also includes Yoshina Gautam, Ahmed Shibl, and Aashish Jha from New York University, Abu Dhabi; Diana Proctor from University of Texas Health Science Center at Houston; Dinesh Bhandari, Sarmila Tandukar, and Jeevan Bahadur Sherchand from the Institute of Medicine in Maharajgunj, Nepal; Guru Prasad Gautam from Tribhuvan University in Nepal; and David Relman from Stanford University.

Funding from the National Institutes of Health, Stanford University, and New York University Abu Dhabi supported this work.

Such materials are increasingly being advocated as environmentally friendly alternatives to plastics, and used in textiles and products including clothing, wet wipes and period products.

However, microfibres of the materials are emitted into the environment through the laundry cycle, the application of sewage sludge as fertilisers, or the simple wear and tear of textile products.

Despite increasing quantities of bio-based products being produced and sold all over the world, there has been little research to assess their potential impact on species and ecosystems.

To address that, a new study in the journal Environmental Science and Technology tested the effects of conventional polyester fibres and two bio-based fibres -viscose and lyocell — on earthworms, a species critical to the health of soils globally.

The study found that in high concentrations of fibres, 30% of earthworms died after 72 hours when exposed to polyester, while those exposed to the bio-based fibres experienced much higher mortality of up to 60% in the case of lyocell and 80% for viscose.

A second experiment, using environmentally relevant concentrations of the fibres, indicated that earthworms housed in soils containing viscose fibres exhibited reduced reproduction compared to those exposed to polyester fibres. Earthworms in the soils containing lyocell fibres showed reduced growth and also higher rates of burrowing within the soil compared to exposure to the other types of fibre.

The researchers say the study highlights the complex nature of global efforts to reduce the threat of microplastic pollution, and the importance of testing new materials being advocated as alternatives to plastics before they are released on the open market.

The study was carried out as part of the BIO-PLASTIC-RISK project, led by researchers at the University of Plymouth and the University of Bath, and supported with £2.6million funding by the Natural Environmental Research Council.

Dr Winnie Courtene-Jones, lead author on the new study and now a Lecturer in Marine Pollution at Bangor University, said: “Over 320,000 tonnes of bio-based and biodegradable fibres were produced globally in 2022 and research shows that substantial quantities of that will end up in the environment. However, evidence of their ecological impacts has been lacking. Our study has shown that bio-based fibres have a range of adverse effects on earthworms — animals which are critical to the functioning of the environment. It highlights the importance of gathering further evidence before alternatives to conventional plastics are made available even more widely.”

The new study follows research published earlier in 2024 which highlighted that being exposed to the materials used in biodegradable teabags can result in earthworm populations experiencing up to 15% greater mortality, and have a detrimental effect on earthworm reproduction.

It has been published just a few weeks before the United Nations gathers world leaders meet in Busan, South Korea, for the final round of negotiations regarding a possible Global Plastics Treaty.

Professor Richard Thompson OBE FRS, senior author on the new study and Head of the University of Plymouth’s International Marine Litter Research Unit, will be at those discussions along with policy makers, scientists and other delegates from across the world.

He added: “It is clear that along with recycling and re-use, tackling plastic pollution will require a reduction in the quantities of plastics used and produced. There is increasing interest in alternative materials that could be used as substitutes for plastic, but this publication further emphasises the importance of testing new innovations in relevant environmental settings prior to widescale adoption. I firmly believe it is possible to tackle the plastic pollution crisis, but independent scientific evidence will be critical in helping us avoid unintended consequences as we look for solutions.”

Today, a Project CETI research team led by Stephanie Gil, Assistant Professor of Computer Science at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), have proposed a new reinforcement learning framework with autonomous drones to find sperm whales and predict where they will surface.

The research is published in Science Robotics.

This new study uses various sensing devices, such as Project CETI aerial drones with very high frequency (VHF) signal sensing capability that leverage signal phase along with the drone’s motion to emulate an ‘antenna array in air’ for estimating directionality of received pings from CETI’s on-whale tags. It demonstrates that it’s possible to predict when and where a whale may surface by using these various sensor data as well as predictive models of sperm whales dive behavior. With that information, Project CETI can now design algorithms for the most efficient route for a drone to rendezvous — or encounter — a whale at the surface. This also opens up possible conservation applications to help ships avoid striking whales while at the surface.

Presenting the Autonomous Vehicles for whAle Tracking And Rendezvous by remote Sensing, or AVATARS framework, this study jointly develops two interrelated components of autonomy and sensing: autonomy, which determines the positioning commands of the autonomous robots to maximize visual whale encounters; and sensing, which measures the Angle-of-Arrival (AOA) from whale tags to inform the decision-making process. Measurements from our autonomous drone to surfaced tags, acoustic AOA from existing underwater sensors, and whale motion models from previous biological studies of sperm whales are provided as inputs to the AVATARS autonomous decision-making algorithm, which in turn aims to minimize missed rendezvous opportunities with whales.

AVATARS is the first co-development of VHF sensing and reinforcement learning decision-making for maximizing rendezvous of robots and whales at sea. A well-known application of time-critical rendezvous is used with rideshare apps, which uses real-time sensing to note the dynamic paths and positions of drivers and potential riders. When a rider requests a ride, it can assign a driver to rendezvous with the rider as efficiently and as timely as possible. Project CETI’s case is similar in that they are real-time tracking the whale, with the goal of coordinating the drone’s rendezvous to meet the whale at the surface.

This research advances Project CETI’s goal of obtaining millions to billions of high-quality, highly contextualized whale vocalizations. The addition of diverse types of data will improve location estimates and routing algorithms — helping Project CETI meet that goal more efficiently.

“I’m excited to contribute to this breakthrough for Project CETI. By leveraging autonomous systems and advanced sensor integration, we’re able to solve key challenges in tracking and studying whales in their natural habitats. This is not only a technological advancement, but also a critical step in helping us understand the complex communications and behaviors of these creatures,” said Gil.

“This research is a major milestone for Project CETI’s mission. We can now significantly enhance our ability to gather high-quality and large-scale dataset on whale vocalizations and the associated behavioral context, putting us one step closer to better listening to and translating what sperm whales are saying,” said David Gruber, Founder and Lead of Project CETI.

“‘This research was an amazing opportunity to test our systems and algorithms in a challenging marine environment. This interdisciplinary work, that combines wireless sensing, artificial intelligence and marine biology, is a prime example of how robotics can be part of the solution for further deciphering the social behavior of sperm whales,” said Ninad Jadhav, Harvard University PhD candidate and first author on the paper.

“This project provides an excellent opportunity to test our algorithms in the field, where robotics and artificial intelligence can enrich data collection and expedite research for broader science in language processing and marine biology, ultimately protecting the health and habitat of sperm whales,” said Sushmita Bhattacharya, a postdoctoral researcher in Gil’s REACT Lab at SEAS.

More information:

https://www.projectceti.org/

The starting point was previous research in which, using temperature and mortality records from 35 European countries, epidemiological models were fitted to estimate heat-related mortality in the summer 2022. Using a dataset of global mean surface temperature anomalies between 1880 and 2022, they estimated the increase in temperatures due to anthropogenic warming for every region. They then subtracted those increases from the recorded temperatures to obtain an estimate of what temperatures would have been in the absence of anthropogenic warming. Finally, using the model developed in the first study, they estimated mortality for a hypothetical scenario where those temperatures would have occurred.

The results, published in npj Climate and Atmospheric Science, showed that the number of heat-related deaths per million inhabitants attributed to anthropogenic warming was twice as high in the Southern regions compared to the rest of Europe.

In line with previous studies, the team found a higher number of heat-related deaths attributed to climate change among women (22,501 out of 37,983 deaths) and people aged 80 years or more (23,881 out of 38,978 deaths) as opposed to men (14,026 out of 25,385 deaths) and people aged 64 years or less (2,702 out of 5,565 deaths).

“This study sheds light on the extent to which global warming impacts public health. While we observe an increase of heat-related mortality across nearly all the countries analysed, not everyone is affected equally, with women and the elderly particularly vulnerable to the adverse effects of rising temperatures,” says Thessa Beck, ISGlobal researcher, and the study’s first author.

Urgent need for ambitious adaptation and mitigation measures

Temperatures in Europe are rising twice as fast as the global average, exacerbating health impacts. But climate change has not only exacerbated heat-related mortality in exceptionally hot summers as in 2022. According to the study’s findings, between 44% and 54% of heat-related summer mortality between 2015 and 2021 can be attributed to global warming. In absolute terms, this corresponds to an annual burden of between 19,000 and 28,000 deaths. By comparison, the figures for 2022 show an alarming 40% increase in heat-related mortality and a two-thirds increase in mortality attributed to anthropogenic warming.

“Our study urgently calls on governments and national authorities in Europe to increase the ambition and effectiveness of surveillance and prevention measures, new adaptation strategies, and global mitigation efforts. Without strong action, record temperatures and heat-related mortality will continue to rise in the coming years,” says Joan Ballester Claramunt, Principal Investigator of the European Research Council (ERC) Consolidator Grant EARLY-ADAPT

Nearly everyone loves the smell of wood smoke. It evokes carefree summer nights under the stars and cozy winter evenings relaxing in front of the fireplace. But the smoke storms caused by extreme wildfire seasons in recent years have been a stark reminder that there can be too much of a good thing.

In the case of wood smoke, it doesn’t take a wildfire to be unhealthy for people and the environment. Wood smoke might smell better than car exhaust, but it is also an environmental pollutant that contributes to serious health impacts. In fact, an old wood stove can emit as much air pollution as five diesel trucks.

Wood Smoke

Smoke, regardless of what material is burning, contains fine particles, including dust and soot. Called particle pollution or particulate matter, these particles range in size from visible to microscopic. Fine particles that are 2.5 µm (micrometers) in diameter or smaller are not visible like dust or soot, but they can become lodged in the respiratory tract. When you look up your local air quality, this fine particulate matter is usually the primary statistic, reported as “PM2.5.”

Particulate matter can damage the lungs, triggering asthma, heart attacks, stroke, irregular heart rhythms, and even heart failure in people who are already at risk for these conditions. Even people who are not at-risk will experience eye and sinus irritation from particle pollution. When pollution is severe, it can lead to bronchitis and other respiratory ailments.

The smoke from burning wood also includes several toxic chemicals, including benzene, formaldehyde, acrolein, and polycyclic aromatic hydrocarbons (PAHs). PAHs are found in soot and tar, and are among the same chemicals that make cigarettes so harmful. Incomplete combustion of wood releases more of these toxic chemicals, as well as carbon monoxide. More than 150 people die annually from carbon monoxide poisoning related to home heating — learn how to vent your wood stove for a safe, warm winter.

Burn Less

In developed countries, the simplest way to avoid pollution from wood smoke is to stop burning wood. But psychological and economic forces make it unlikely that we will abandon burning wood completely. Even so, we can be more judicious about when and how much we burn wood. If you have a fireplace or woodstove at home, avoid using it during seasons when warmer temperatures allow smoke to settle around the house.

Many people have a hard time imagining camping without a campfire. Cooking over an open fire, making s’mores, and sitting around the fire under the stars are all iconic camping experiences. But nowadays many areas institute burn bans throughout much of the year. Complying with burn bans is not optional – campfires have caused more than 11,000 wildfires in the U.S. since 2006.

It might not be as picturesque, but a propane camp stove is much safer than a campfire. And if you want to avoid an open flame altogether, consider a solar oven.

Burn Cleaner

In parts of the world where people depend on wood fires for cooking, traditional cookstoves are a greater health risk factor than poor water, sanitation, and other environmental hazards. In these places, people need cleaner cookstoves to replace open fires. If you are considering supporting clean cookstove charities, as not all programs are effective and honest. The U.S. Attorney for the Southern District of New York recently filed charges against CQC Impact Investors, accusing the company of fabricated “tens of millions of dollars” worth of carbon credits.

Incomplete burning releases more smoke and toxic chemicals. For complete combustion, only use dry, seasoned wood or cleaner-burning manufactured fire logs; learn how to build a fire that catches quickly, and always put out your fire completely. A smoldering fire also releases more smoke and harmful chemicals. And never burn garbage, treated lumber, or plastics.

Standard fireplaces put out 28 times as much particulate matter as a new wood stove, and a pellet stove releases about half of what a new wood stove puts out. Both wood and gas-burning fireplace inserts generate less smoke and provide the same amount of heat with less fuel than an open fireplace. If you have a wood-burning fireplace, have it inspected annually by a chimney sweep certified by the Chimney Safety Institute of America to make sure it’s operating properly.

Wood stoves should also be inspected annually for safety and efficiency. Older woodstoves release 15 to 30 grams of smoke per hour. New, EPA-certified stoves produce 4.5 grams per hour or less. When you’re ready to upgrade your stove, check the current list of EPA-certified wood heaters or consider switching your home to a cleaner heating system. And no matter what heat source you use, make sure you heat your home as efficiently as possible.

Editor’s Note: This article was originally published on October 12, 2020 and updated in October 2024.

To resolve this controversy, Dr. Ruijing Ni, the first author of the study published today in the journal One Earth, and her colleagues at the Max Planck Institute for Chemistry have conducted a comprehensive global meta-analysis with researchers from China, the USA, and Australia. The research team determined the data from 68 epidemiologic studies from 2019 conducted across 22 countries, including those in North America, Western Europe, East Asia, South Asia, and Africa. They conclude that there is now sufficient evidence with high confidence level to support an association between long-term exposure to ambient PM_2.5 and asthma.

11 percent of new cases of asthma in Germany are attributable to particulate matter

“We estimate that globally in 2019, almost a third of asthma cases are attributable to long-term PM_2.5 exposure, corresponding to 63.5 million existing cases and 11.4 million new cases. In Germany, the pollution may have been responsible for 11 percent of new asthma cases, which corresponds to 28,000 people. We also find that the risk of asthma associated with PM_2.5 is much higher in children than in adults, reflecting the age-related vulnerability,” says Dr. Ni.

Typically, the full maturation of lung and immune function is gradually completed until early adulthood. As a result, children may be more susceptible to air pollution exposure, which can lead to airway oxidative stress, inflammation, and hyper-responsiveness, as well as changes in immunological responses and respiratory sensitization to allergens. All these factors play a role in the development of asthma.

Further using these data, the research team established exposure-response curves for both childhood and adult asthma. Such curves are widely employed to quantitatively assess health risks by illustrating the relationship between the level of exposure to a particular substance, e.g., PM_2.5 and the magnitude of the effect it produces, e.g., asthma risk. The exposure-response curves were determined by incorporating evidence from countries and regions across various income levels, which capture the global variation in PM_2.5 exposure. “This initiative is important for quantifying global health effects of air pollution,” comments Prof. Yuming Guo, an epidemiologist from Monash University.

Countries with different income levels and particulate matter pollution considered

Populations in low- and middle-income countries (LMICs) are typically exposed to higher concentrations of air pollution and bear a greater burden of PM_2.5. In contrast, research on the health effects of PM_2.5 has been limited in these regions previously, with the majority of studies conducted in North America and Western Europe. Consequently, attempting a global health impact assessment of PM_2.5 exposure necessitates extrapolating exposure-response associations observed in high-income countries to LMICs. The approach may introduce large uncertainty due to the differences in air pollution sources, healthcare systems, and demographic characteristics between high-income countries and LMICs.

The inclusion of evidence from several LMICs mitigates the limitation in approach and enables the exposure-response curves to be applicable to assess city- to global-scale attributable burden of asthma, as well as asthma health benefits associated with air pollution reductions, e.g., health benefits obtained from policy-driven reductions in air pollution under different scenarios.

“Our findings highlight the urgent need for policymakers to enforce stringent legislation to continuously combat air pollution, while personal protective measures, such as wearing masks, can also help reduce individual exposure and mitigate the risk of asthma,” emphasizes Prof. Yafang Cheng, the corresponding author of the study and the director at the Max Planck Institute for Chemistry.

The study was conducted by researchers from Max Planck Institute for Chemistry (Germany), Institute of Atmospheric Physics at the Chinese Academy of Sciences (China), University of Washington (USA), and Monash University (Australia).