Cookies help us run our site more efficiently.

By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. View our Privacy Policy for more information or to customize your cookie preferences.

Accept Deny

GoGreenNation news

Quantifying the Fallout: Particulate Matter and Public Health at the Salton Sea

News Feed
Wednesday, May 29, 2024

Research highlights that dust stirred by desert winds from the exposed Salton Sea bed significantly increases air pollution, disproportionately affecting nearby disadvantaged communities. The situation has worsened due to reduced water inflows, a consequence of water diversions for urban use in San Diego. (Artist’s concept.) Credit: SciTechDaily.comIncreased dust from the Salton Sea’s drying lakebed is raising air pollution levels, impacting disadvantaged communities the most, with ongoing water diversions exacerbating the situation.When desert winds stir up dust from the Salton Sea’s exposed lakebed, nearby communities suffer from increased air pollution. The deterioration coincides with reduced flows into California’s largest lake, a new research paper published today (May 29) in the American Journal of Agricultural Economics finds.Disadvantaged communities have been affected more than others in the areas near the Salton Sea, which has been shrinking for years, said Eric Edwards, the paper’s co-leading author. He is an assistant professor of agricultural economics at the University of California, Davis, who did the research while at North Carolina State University. “We have a dusty area, and any time there is wind, it’s going to pick up dust and move it around,” Edwards said. “We think this new dust is increasing the amount of pollution faced by disadvantaged communities in the region surrounding the lake.”The dry lakebed of Calfironia’s Salton Sea. Credit: Emily C. Dooley, UC DavisAn Overflowing RiverThe Salton Sea formed in 1905 after the Colorado River overflowed its banks and the floodwaters settled into what was known as the Salton Sink. It was primarily fed by water runoff from agricultural operations for almost a century. As the southern part of California struggled to meet growing water demand, the Imperial Irrigation District agreed to send water to San Diego for urban use.Imperial, which supplies water to vast desert farms as well as seven towns and two special districts, is the largest user of Colorado River water. The agreement with San Diego required agricultural water users to increase efficiency and reduce their water consumption, which reduced water running into the Salton Sea, Edwards said.The reductions increased the lake’s salt content, which is higher than in the Pacific Ocean. This also harmed wildlife habitats and created localized air pollution. The area is the subject of many environmental restoration projects.Studying ImplicationsEdwards and others used a particle transport model to study the effects of changing water diversions on particulate pollution.They found that the paths of fine particulate matter — which can cause asthma, heart and respiratory issues when inhaled — were associated with higher air pollution readings after Imperial began reducing runoff water to the Salton Sea around 2011 in order to transfer it to San Diego, a practice that continues today.Researchers modeled lakebed exposure by dividing the lake’s shoreline into 1-square-kilometer grids and collected air pollution data daily for over 20 years, from 1998 to 2018. They added data about the exposed lakebed, or playa, and used a sophisticated physics model called HYSPLIT to factor in wind levels and particle size to track the movement of dust over time. State health screening information available by ZIP code added more to the story by pinpointing disadvantaged areas, asthma rates and other vulnerabilities.Lake levels were higher in 1998 before the transfers, so the change was not evident until later years, when the lakebed became more exposed.“We show that during that post-2011, there is an increase in particles going through disadvantaged communities relative to non-disadvantaged communities, which are farther away from the sea,” Edwards said.In the paper, the pollution paths are depicted on a map of the state. The Salton Sea is marked with a black dot, and red lines radiate from there to distances of 100 miles or more.“From every exposed grid cell you have these paths predicting where the particles are going based on physics,” Edwards said. “That’s the path of emissions.”Prior research suggests that dust particles from newly exposed playa are more susceptible to wind erosion.“There’s lots of evidence that playa is particularly emissive in terms of dust,” Edwards said. “If it’s dry, those particles get picked up readily by the wind and create dust — and at rates higher than areas that have been exposed to the wind over long periods of time.”Informing Decision-MakersEdwards said policymakers and regulators should consider the health and environmental impacts of water diversions in their decision-making.“The drying up of the Salton Sea has serious health consequences that have generally fallen on more disadvantaged populations, who may not be well equipped to advocate for policies that improve their health,” he said. “Policymakers need to think about how to facilitate the movement of water via market transactions, which are essential, while also accounting for potential negative effects on the environment.”Reference: “Water, dust, and environmental justice: The case of agricultural water diversions” 29 May 2024, American Journal of Agricultural Economics. DOI: 10.1111/ajae.12472Ryan Abman from San Diego State University and Dana Hernandez-Cortes from Arizona State University contributed equally with Edwards to the research and journal article.The U.S. Department of Agriculture’s National Institute of Food and Agriculture supported this research.

Increased dust from the Salton Sea’s drying lakebed is raising air pollution levels, impacting disadvantaged communities the most, with ongoing water diversions exacerbating the situation....

Dry Lakebed Pollution

Research highlights that dust stirred by desert winds from the exposed Salton Sea bed significantly increases air pollution, disproportionately affecting nearby disadvantaged communities. The situation has worsened due to reduced water inflows, a consequence of water diversions for urban use in San Diego. (Artist’s concept.) Credit: SciTechDaily.com

Increased dust from the Salton Sea’s drying lakebed is raising air pollution levels, impacting disadvantaged communities the most, with ongoing water diversions exacerbating the situation.

When desert winds stir up dust from the Salton Sea’s exposed lakebed, nearby communities suffer from increased air pollution. The deterioration coincides with reduced flows into California’s largest lake, a new research paper published today (May 29) in the American Journal of Agricultural Economics finds.

Disadvantaged communities have been affected more than others in the areas near the Salton Sea, which has been shrinking for years, said Eric Edwards, the paper’s co-leading author. He is an assistant professor of agricultural economics at the University of California, Davis, who did the research while at North Carolina State University.

“We have a dusty area, and any time there is wind, it’s going to pick up dust and move it around,” Edwards said. “We think this new dust is increasing the amount of pollution faced by disadvantaged communities in the region surrounding the lake.”

Salton Sea Dry Lakebed

The dry lakebed of Calfironia’s Salton Sea. Credit: Emily C. Dooley, UC Davis

An Overflowing River

The Salton Sea formed in 1905 after the Colorado River overflowed its banks and the floodwaters settled into what was known as the Salton Sink. It was primarily fed by water runoff from agricultural operations for almost a century. As the southern part of California struggled to meet growing water demand, the Imperial Irrigation District agreed to send water to San Diego for urban use.

Imperial, which supplies water to vast desert farms as well as seven towns and two special districts, is the largest user of Colorado River water. The agreement with San Diego required agricultural water users to increase efficiency and reduce their water consumption, which reduced water running into the Salton Sea, Edwards said.

The reductions increased the lake’s salt content, which is higher than in the Pacific Ocean. This also harmed wildlife habitats and created localized air pollution. The area is the subject of many environmental restoration projects.

Studying Implications

Edwards and others used a particle transport model to study the effects of changing water diversions on particulate pollution.

They found that the paths of fine particulate matter — which can cause asthma, heart and respiratory issues when inhaled — were associated with higher air pollution readings after Imperial began reducing runoff water to the Salton Sea around 2011 in order to transfer it to San Diego, a practice that continues today.

Researchers modeled lakebed exposure by dividing the lake’s shoreline into 1-square-kilometer grids and collected air pollution data daily for over 20 years, from 1998 to 2018. They added data about the exposed lakebed, or playa, and used a sophisticated physics model called HYSPLIT to factor in wind levels and particle size to track the movement of dust over time. State health screening information available by ZIP code added more to the story by pinpointing disadvantaged areas, asthma rates and other vulnerabilities.

Lake levels were higher in 1998 before the transfers, so the change was not evident until later years, when the lakebed became more exposed.

“We show that during that post-2011, there is an increase in particles going through disadvantaged communities relative to non-disadvantaged communities, which are farther away from the sea,” Edwards said.

In the paper, the pollution paths are depicted on a map of the state. The Salton Sea is marked with a black dot, and red lines radiate from there to distances of 100 miles or more.

“From every exposed grid cell you have these paths predicting where the particles are going based on physics,” Edwards said. “That’s the path of emissions.”

Prior research suggests that dust particles from newly exposed playa are more susceptible to wind erosion.

“There’s lots of evidence that playa is particularly emissive in terms of dust,” Edwards said. “If it’s dry, those particles get picked up readily by the wind and create dust — and at rates higher than areas that have been exposed to the wind over long periods of time.”

Informing Decision-Makers

Edwards said policymakers and regulators should consider the health and environmental impacts of water diversions in their decision-making.

“The drying up of the Salton Sea has serious health consequences that have generally fallen on more disadvantaged populations, who may not be well equipped to advocate for policies that improve their health,” he said. “Policymakers need to think about how to facilitate the movement of water via market transactions, which are essential, while also accounting for potential negative effects on the environment.”

Reference: “Water, dust, and environmental justice: The case of agricultural water diversions” 29 May 2024, American Journal of Agricultural Economics.
DOI: 10.1111/ajae.12472

Ryan Abman from San Diego State University and Dana Hernandez-Cortes from Arizona State University contributed equally with Edwards to the research and journal article.

The U.S. Department of Agriculture’s National Institute of Food and Agriculture supported this research.

Read the full story here.
Photos courtesy of

Related News

Ignore the Influencers: Simple Showers Are Still Best

By Carole Tanzer Miller HealthDay ReporterSATURDAY, Dec. 13, 2025 (HealthDay News) — Listen to the influencers, skin-care specialists say, and your...

By Carole Tanzer Miller HealthDay ReporterSATURDAY, Dec. 13, 2025 (HealthDay News) — Listen to the influencers, skin-care specialists say, and your daily shower could do more harm than good."Your skin is a barrier," said Dr. Nicole Negbenebor, a dermatologic surgeon at University of Iowa Health Care, told The Associated Press. "So you want to treat it right, and then sometimes there can be too much of a good thing."If you’re double-cleansing, exfoliating, piling on scented body rubs and shower oils and spending a lot of time in the water, you’re probably going overboard, she and other skin-care experts agree.A daily shower with lukewarm water and hypoallergenic cleanser — preferably one that’s fragrance-free, and a slather of lotion or oil afterward are all you need, they say.Here’s a guide from dermatologists to sudsing up without getting carried away:Pay attention to time and temperature. Staying in the shower too long or cranking the temperature up too high can strip away natural oils your skin needs. The upshot: You’ll be dry and irritated.Pick the right soap. Choose one, dermatologists suggest, for sensitive skin and avoid antibacterial soaps, which can cause dryness. (Antibacterial soaps can, however, be beneficial for folks with hidradenitis suppurativa, an autoimmune condition that causes abscesses and boils on the skin, they point out.)Despite the influencers, double-cleansing isn’t necessary. No need, doctors say, to use oil-based cleansers to break down makeup and excess oil and then a water-based cleanser to remove any residue. And, they add, you sure don’t need to do that to your whole body."People overuse soap all the time," Dr. Olga Bunimovich, an assistant professor of dermatology at the University of Pittsburgh, told The AP. "You should not be soaping up all of your skin period." Instead, she advised, use soap to wash skin folds and your privates.Oil up. Once you’re out of the shower but still damp, an oil will lock in moisture that hydrates the skin, Negbenebor said. Just remember: Oil itself is a sealant, not a moisturizer.Don’t go overboard with exfoliating. Using a body scrub or loofah to remove dead cells is good for the skin, but not every day, especially if you have dry skin, acne or eczema. Using products that contain lactic or glycolic acid is a gentler way to exfoliate — but not all the time.While you’re being kind to your skin, think about the environment, too. Nearly 17% of U.S. indoor water use is in the shower, according to the U.S. Environmental Protection Agency. Shorter showers are good for the earth — and a lukewarm one that lasts long enough to clean your body should be sufficient most of the time.The University of Nebraska-Lincoln has more about showering.SOURCE: The Associated Press, July 10, 2025Copyright © 2025 HealthDay. All rights reserved.

Health
Water

New method improves the reliability of statistical estimations

The technique can help scientists in economics, public health, and other fields understand whether to trust the results of their experiments.

Let’s say an environmental scientist is studying whether exposure to air pollution is associated with lower birth weights in a particular county.They might train a machine-learning model to estimate the magnitude of this association, since machine-learning methods are especially good at learning complex relationships.Standard machine-learning methods excel at making predictions and sometimes provide uncertainties, like confidence intervals, for these predictions. However, they generally don’t provide estimates or confidence intervals when determining whether two variables are related. Other methods have been developed specifically to address this association problem and provide confidence intervals. But, in spatial settings, MIT researchers found these confidence intervals can be completely off the mark.When variables like air pollution levels or precipitation change across different locations, common methods for generating confidence intervals may claim a high level of confidence when, in fact, the estimation completely failed to capture the actual value. These faulty confidence intervals can mislead the user into trusting a model that failed.After identifying this shortfall, the researchers developed a new method designed to generate valid confidence intervals for problems involving data that vary across space. In simulations and experiments with real data, their method was the only technique that consistently generated accurate confidence intervals.This work could help researchers in fields like environmental science, economics, and epidemiology better understand when to trust the results of certain experiments.“There are so many problems where people are interested in understanding phenomena over space, like weather or forest management. We’ve shown that, for this broad class of problems, there are more appropriate methods that can get us better performance, a better understanding of what is going on, and results that are more trustworthy,” says Tamara Broderick, an associate professor in MIT’s Department of Electrical Engineering and Computer Science (EECS), a member of the Laboratory for Information and Decision Systems (LIDS) and the Institute for Data, Systems, and Society, an affiliate of the Computer Science and Artificial Intelligence Laboratory (CSAIL), and senior author of this study.Broderick is joined on the paper by co-lead authors David R. Burt, a postdoc, and Renato Berlinghieri, an EECS graduate student; and Stephen Bates an assistant professor in EECS and member of LIDS. The research was recently presented at the Conference on Neural Information Processing Systems.Invalid assumptionsSpatial association involves studying how a variable and a certain outcome are related over a geographic area. For instance, one might want to study how tree cover in the United States relates to elevation.To solve this type of problem, a scientist could gather observational data from many locations and use it to estimate the association at a different location where they do not have data.The MIT researchers realized that, in this case, existing methods often generate confidence intervals that are completely wrong. A model might say it is 95 percent confident its estimation captures the true relationship between tree cover and elevation, when it didn’t capture that relationship at all.After exploring this problem, the researchers determined that the assumptions these confidence interval methods rely on don’t hold up when data vary spatially.Assumptions are like rules that must be followed to ensure results of a statistical analysis are valid. Common methods for generating confidence intervals operate under various assumptions.First, they assume that the source data, which is the observational data one gathered to train the model, is independent and identically distributed. This assumption implies that the chance of including one location in the data has no bearing on whether another is included. But, for example, U.S. Environmental Protection Agency (EPA) air sensors are placed with other air sensor locations in mind.Second, existing methods often assume that the model is perfectly correct, but this assumption is never true in practice. Finally, they assume the source data are similar to the target data where one wants to estimate.But in spatial settings, the source data can be fundamentally different from the target data because the target data are in a different location than where the source data were gathered.For instance, a scientist might use data from EPA pollution monitors to train a machine-learning model that can predict health outcomes in a rural area where there are no monitors. But the EPA pollution monitors are likely placed in urban areas, where there is more traffic and heavy industry, so the air quality data will be much different than the air quality data in the rural area.In this case, estimates of association using the urban data suffer from bias because the target data are systematically different from the source data.A smooth solutionThe new method for generating confidence intervals explicitly accounts for this potential bias.Instead of assuming the source and target data are similar, the researchers assume the data vary smoothly over space.For instance, with fine particulate air pollution, one wouldn’t expect the pollution level on one city block to be starkly different than the pollution level on the next city block. Instead, pollution levels would smoothly taper off as one moves away from a pollution source.“For these types of problems, this spatial smoothness assumption is more appropriate. It is a better match for what is actually going on in the data,” Broderick says.When they compared their method to other common techniques, they found it was the only one that could consistently produce reliable confidence intervals for spatial analyses. In addition, their method remains reliable even when the observational data are distorted by random errors.In the future, the researchers want to apply this analysis to different types of variables and explore other applications where it could provide more reliable results.This research was funded, in part, by an MIT Social and Ethical Responsibilities of Computing (SERC) seed grant, the Office of Naval Research, Generali, Microsoft, and the National Science Foundation (NSF).

Health
Forests
Science

Gas Stoves Are Poisoning Americans by Releasing Toxic Fumes Associated With Asthma and Lung Cancer

In the United States, gas stoves are the main source of indoor nitrogen dioxide—a toxic gas tied to many health problems—according to a new study

Gas Stoves Are Poisoning Americans by Releasing Toxic Fumes Associated With Asthma and Lung Cancer In the United States, gas stoves are the main source of indoor nitrogen dioxide—a toxic gas tied to many health problems—according to a new study Sarah Kuta - Daily Correspondent December 11, 2025 9:13 a.m. Gas stoves are responsible for more than half of some Americans’ total exposure to toxic nitrogen dioxide, a new study suggests. Pexels A hidden danger may be lurking in your kitchen. Many Americans are breathing in nitrogen dioxide—a harmful pollutant that’s been linked with asthma and lung cancer—from fumes emitted by their gas stoves. A new study, published this month in the journal PNAS Nexus, suggests that gas stoves are the main source of indoor nitrogen dioxide pollution in the United States, responsible for more than half of some Americans’ total exposure to the gas. “We’ve spent billions of dollars cleaning up our air outdoors and nothing to clean up our air indoors,” study co-author Robert Jackson, an environmental scientist at Stanford University, tells SFGATE’s Anna FitzGerald Guth. “As our air outdoors gets cleaner and cleaner, a higher proportion of the pollution we breathe comes from indoor sources.” Scientists and public health experts have long known that nitrogen dioxide is bad for human health. The reddish-brown gas can irritate airways and worsen or even contribute to the development of respiratory diseases like asthma. Children and older individuals are particularly susceptible to its effects. Nitrogen dioxide is a byproduct of burning fuel, so most emissions come from vehicles, power plants and off-road equipment. However, indoors, the primary culprit is the gas stove, the household appliance that burns natural gas or propane to produce controlled flames under individual burners. It’s relatively easy to keep tabs on outdoor nitrogen dioxide concentrations and estimate their corresponding exposure risks, thanks to satellites and ground-level stations located across the country. By contrast, however, indoor sources are “neither systematically monitored nor estimated,” the researchers write in the paper. Did you know? Bans on gas Berkeley, California, became the first city to prohibit gas hookups in most new buildings in 2019, although the ordinance was halted in 2024 after the California Restaurant Association sued. Still, 130 local governments have now implemented zero-emission building ordinances, according to the Building Decarbonization Coalition. For the study, Jackson and his colleagues performed a ZIP-code-level estimate of how much total nitrogen dioxide communities are exposed to. Information came from two databases tracking outdoor nitrogen dioxide concentrations and a building energy use database, which helped the team construct characteristics of 133 million residential dwellings across the country, along with their home appliances. Among individuals who use gas stoves, the appliances are responsible for roughly a quarter of their overall nitrogen dioxide exposure on average, the team found. For those who cook more frequently or for longer durations, gas stoves can be responsible for as much as 57 percent of their total exposure. “Our research shows that if you use a gas stove, you’re often breathing as much nitrogen dioxide pollution indoors from your stove as you are from all outdoor sources combined,” says Jackson in a Stanford statement. Individuals who use gas stoves are exposed to roughly 25 percent more total residential nitrogen dioxide over the long term than those who use electric stoves, which do not emit the gas. Total exposure tends to be highest in big cities, where people often have small living spaces and outdoor levels are also high. Switching from a gas to an electric stove would help roughly 22 million Americans dip below the maximum nitrogen dioxide exposure levels recommended by the World Health Organization, the analyses suggest. The authors recommend replacing gas stoves with electric models whenever possible. “You would never willingly stand over the tailpipe of your car, breathing in pollution,” Jackson tells Women’s Health’s Korin Miller. “Why breathe the same toxins every day in your kitchen?” Dylan Plummer, acting deputy director for building electrification for the Sierra Club, a nonprofit environmental organization, agrees. Plummer, who was not involved with the research, tells Inside Climate News’ Phil McKenna that “years from now, we will look back at the common practice of burning fossil fuels in our homes with horror.” If swapping stoves is not possible, experts have some other tips for reducing nitrogen dioxide exposure. “One thing people could do is to minimize the time the stoves are on,” Jamie Alan, a toxicologist at Michigan State University who was not involved with the research, tells Women’s Health. “Another suggestion would be to increase ventilation,” such as by turning on the range hood and opening a window. Other suggestions by the New York Times’ Rachel Wharton include using a portable induction countertop unit or electric kitchen gadgets like tea kettles, toaster ovens and slow cookers. Get the latest stories in your inbox every weekday.

Health
Climate
Energy

Parents Might Pass Depression Down To Kids Through One Specific Symptom, Experts Say

By Dennis Thompson HealthDay ReporterTHURSDAY, Dec. 11, 2025 (HealthDay News) — Children of depressed parents are more likely to develop depression...

By Dennis Thompson HealthDay ReporterTHURSDAY, Dec. 11, 2025 (HealthDay News) — Children of depressed parents are more likely to develop depression themselves, and a new study suggests this risk might be tied to one specific symptom of depression.It’s already known that depression in parents can affect how children’s brains respond to positive and negative feedback, researchers said.“If parents are experiencing forms of depression where they’re not enjoying things and aren’t interested in things, that seems to be impacting how their kids are responding to what’s going on around them,” senior researcher Brandon Gibb, director of the Mood Disorders Institute at Binghamton University, said in a news release.“They’re less reactive to positive things and negative things,” he continued. “It seems that parents’ experiences of anhedonia is the key feature of depression impacting how children’s brains are responding, at least in our study, rather than other common symptoms of depression.”For the new study, researchers performed a lab experiment involving more than 200 parents and children ages 7 to 11.The experiment was designed to see how parents’ anhedonic symptoms affect children’s brain responses to positive and negative feedback.“The idea is that if you have this risk factor of being less interested or less engaged or finding things less enjoyable, maybe that’s reflected in how your brain responds to environmental feedback,” said lead researcher Alana Israel, a doctoral student at Binghamton University, a branch of the State University of New York. “Children of parents who have higher levels of anhedonic depressive symptoms should show a reduced response while other depressive symptoms theoretically should not be as related to this specific brain response,” Israel explained in a news release.In the experiment, children were presented with two doors and asked to guess the one with a prize behind it. If they chose the right door, they won money; if they chose wrong, they lost money.Results showed that kids’ response to either winning or losing money was blunted if their parents had higher levels of anhedonic symptoms. “What that tells us is that there is something specific about parents’ anhedonia that may impact children’s neural responses,” Israel said. “It further specifies a group of children who might be at heightened risk for loss of interest or pleasure and lack of engagement, which is a core feature of depression.”Future research should investigate how family dynamics might change if parents with anhedonic symptoms receive treatment or start to feel better, the team said.Researchers said it’s also important to examine whether children’s responses to other sorts of feedback, like social feedback from peers, are also affected by parents’ depression.“There are researchers looking at interventions that are designed to increase positive mood, positive engagement and positive parent-child relationships,” Israel said. “It will be important to see if these findings can identify families who might be most likely to benefit from those types of interventions.”SOURCE: Binghamton University, news release, Dec. 4, 2025Copyright © 2025 HealthDay. All rights reserved.

Health

We may finally know what a healthy gut microbiome looks like

Our gut microbiome has a huge influence on our overall health, but we haven't been clear on the specific bacteria with good versus bad effects. Now, a study of more than 34,000 people is shedding light on what a healthy gut microbiome actually consists of

The trillions of microscopic bacteria that reside in our gut have an outsized role in our healthTHOM LEACH/SCIENCE PHOTO LIBRARY We often hear talk of things being good for our microbiome, and in turn, good for our health. But it wasn’t entirely clear what a healthy gut microbiome consisted of. Now, a study of more than 34,000 people has edged us closer towards understanding the mixes of microbes that reliably signal we have low inflammation, good immunity and healthy cholesterol levels. Your gut microbiome can influence your immune system, rate of ageing and your risk of poor mental health. Despite a profusion of home tests promising to reveal the make-up of your gut community, their usefulness has been debated, because it is hard to pin down what defines a “good” microbial mix. Previous measures mainly looked at species diversity, with a greater array of bacteria being better. But it is difficult to identify particular communities of interacting organisms that are implicated in a specific aspect of our health, because microbiomes vary so much from person to person. “There is a very intricate relationship between the food we eat, the composition of our gut microbiome, and the effects the gut microbiome has on our health. The only way to try to map these connections is having large enough sample sizes,” says Nicola Segata at the University of Trento in Italy. To create such a map, Segata and his colleagues have assessed a dataset from more than 34,500 people who took part in the PREDICT programme in the UK and US, run by microbiome testing firm Zoe, and validated the results against data from 25 other cohorts from Western countries. Of the thousands of species that reside in the human gut, the researchers focused on 661 bacterial species that were found in more than 20 per cent of the Zoe participants. They used this to determine the 50 bacteria most associated with markers of good health – assessed via markers such as body mass index and blood glucose levels – and the 50 most linked to bad health. The 50 “good bug” species – 22 of which are new to science – seem to influence four key areas: heart and blood cholesterol levels; inflammation and immune health; body fat distribution; and blood sugar control. The participants who were deemed healthy, because they had no known medical conditions, had about 3.6 more of these species than people with a condition, while people at a healthy weight hosted about 5.2 more of them than those with obesity. The researchers suggest that good or bad health outcomes may come about due to the vital role the gut microbiome plays in releasing chemicals involved in cholesterol transport, inflammation reduction, fat metabolism and insulin sensitivity. As to the specific species that were present, most microbes in both the “good” and “bad” rankings belong to the Clostridia class. Within this class, species in the Lachnospiraceae family featured 40 times, with 13 seemingly having favourable effects and 27 unfavourable. “The study highlights bacterial groups that could be further investigated regarding their potential positive or negative impact [on] health conditions, such as high blood glucose levels or obesity,” says Ines Moura at the University of Leeds, UK. The link between these microbes and diet was assessed via food questionnaires and data logged on the Zoe app, where users are advised to aim for at least 30 different plants a week and at least three portions a day of fermented foods, with an emphasis on fibre and not too many ultra processed options. The researchers found that most of the microbes either aligned with a generally healthy diet and better health, or with a worse diet and poorer health. But 65 of the 661 microbes didn’t fit in. “These 65 bacteria are a testament to the fact that the picture is still more complex than what we saw,” says Segata, who also works as a consultant for Zoe. “The effects may depend on the other microbes that are there, or the specific strain of the bacterium or the specific diet.” This sorting of “good” versus “bad” bacteria has enabled the researchers to create a 0 to 1000 ranking scale for the overall health of someone’s gut microbiota, which is already used as part of Zoe’s gut health tests. “Think of a healthy gut microbiome as a community of chemical factories. We want large numbers of species, we want the good ones outnumbering the bad ones, and when you get that, then you’re producing really healthy chemicals, which have impacts across the body,” says team member Tim Spector at King’s College London and co-founder of Zoe. This doesn’t mean the ideal healthy gut microbiome has been pinned down, though. “Defining a healthy microbiome is a difficult task, as the gut microbiome composition is impacted by diet, but it can also change with environmental factors, age and health conditions that require long-term medication,” says Moura. “We really need to think about our body and our microbiome as two complex systems that together make one even more complex system,” says Segata. “When you change one thing, everything is modified a bit as a consequence. Understanding what is cause and effect in many cases can be very intricate.” Bigger studies are needed to tease out these links and cover more of the global population, says Segata. However, once we have established the baseline of your health and microbiome, it should become possible to recommend specific foods to tweak your gut bacteria, he says.

Health
Chemicals
Science

Suggested Viewing

Lead in the Land

Lead in the Land is a documentary focusing on the harsh reality and far-reaching effects of lead poisoning, an invisible and insidious threat afflicting thousands of children in the United States. The film sheds light on the circumstances around lead poisoning, examining its causes, effects and potential solutions.

Chemicals
Social Justice
Health

Living with the Coronavirus

In next years we must learn to live together with mr. Coronavirus, as the experts say. Are we ready?

Health
Student
Youth

Ground Operations: Battlefields to Farmfields

Combat veterans from the wars in Iraq & Afghanistan find a new mission and personal healing with new careers as organic farmers and ranchers.

Health
Agriculture
Government

Allergy Alert: Paranoia in Our Immune System

From peanuts and pollen to cats and dust mites, allergy rates are soaring dramatically all over the globe, with inoffensive substances triggering life-threatening physical responses. Experts are predicting that by 2050, one in two will suffer from an allergy. Why are our immune systems overreacting in this way? To stem the tide of the epidemic, scientists are investigating the interface between genetics, environmental factors and our modern lifestyle, and developing revolutionary new approaches to prevention and treatment.

Science
Crisis
Health

We Are Nature

We made this short film under lockdown conditions throughout the pandemic of Covid-19. The film argues that policies are not enough to prevent a future outbreak. We need a paradigm shift in how we view nature and the rest of life on this planet. The film was made remotely via zoom, a fact made clear in the style of the film. Our speakers appear on screens, which we filmed from inside our homes. Each speaker offers a different perspective on the origins of the pandemic in the ways we see and value nature. If humans can’t escape their connection to the natural world, it’s time for a better one. The health of us and the planet depends on it.

Health
Nature
Animals

Join us to forge
a sustainable future

Our team is always growing.
Become a partner, volunteer, sponsor, or intern today.
Let us know how you would like to get involved!

CONTACT US

sign up for our mailing list to stay informed on the latest films and environmental headlines.

Subscribers receive a free day pass for streaming Cinema Verde.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.