Almost all world’s oceans damaged by human impact

Just 13% of the world’s oceans remain untouched by the damaging impacts of humanity, the first systematic analysis has revealed. Outside the remotest areas of the Pacific and the poles, virtually no ocean is left harbouring naturally high levels of marine wildlife.
Huge fishing fleets, global shipping and pollution running off the land are combining with climate change to degrade the oceans, the researchers found. Furthermore, just 5% of the remaining ocean wilderness is within existing marine protection areas.
“We were astonished by just how little marine wilderness remains,” says Kendall Jones, at the University of Queensland, Australia, and the Wildlife Conservation Society, who led the new research. “The ocean is immense, covering over 70% of our planet, but we’ve managed to significantly impact almost all of this vast ecosystem.”
Jones said the last remnants of wilderness show how vibrant ocean life was before human activity came to dominate the planet. “They act as time machines,” he said. “They are home to unparalleled levels of marine biodiversity and some of the last places on Earth you find large populations of apex predators like sharks.”
Much of the wilderness is in the high seas, beyond the protected areas that nations can create. The scientists said a high seas conservation treaty is urgently needed, with negotiations beginning in September under the UN Law of the Sea convention. They also said the $4bn a year in government subsidies spent on high seas fishing must be cut. “Most fishing on the high seas would actually be unprofitable if it weren’t for big subsidies,” Jones said.
The new work joins recent studies in highlighting the threat to oceans. Scientists warned in January that the oceans are suffocating, with huge dead zones quadrupling since 1950, and in February, new maps revealed half of world’s oceans are now industrially fished. “Oceans are under threat now as never before in human history,” said Sir David Attenborough at the conclusion of the BBC series Blue Planet 2 in December.
The new research, published in the journal Current Biology, classified areas of ocean as wilderness if they were in the lowest 10% of human impacts, either from one source, such as bottom trawling, or a combination of them all.
As most are on the high seas, very few are protected. “This means the vast majority of marine wilderness could be lost at any time, as improvements in technology allow us to fish deeper and ship farther than ever before,” Jones said.
Climate change is causing growing damage and Jones said Arctic wilderness areas protected by ice cover in the 1970s had now been lost after the ice melted and fishing boats were able to access them. It is increasingly a global problem, he said: “In future, as climate change gets worse, I think you can definitely say pretty much everywhere in the ocean is going to come under increasing level of threat.”
There are some bright spots, such as the remote corals in the British Indian Ocean Territory around Diego Garcia, from which islanders were controversially removed in the 1960s. In the Antarctic, major fishing companies now back the creation of the world’s biggest marine sanctuary.
The new study aimed to include the maximum area of likely wilderness, said Ward Appeltans, at the Intergovernmental Oceanographic Commission run by Unesco: “So the claim that only 13% of ocean wilderness remains is all the more striking.” He said the research focused on the ocean floor, and did not include impacts on the water column above it, and backed calls for a global ocean conservation treaty.
Jones said: “Beyond just valuing nature for nature’s sake, having these large intact seascapes that function in a way that they always have done is really important for the Earth. They maintain the ecological processes that are how the climate and Earth system function – [without them] you can start seeing big knock-on effects with drastic and unforeseen consequences.”

UK theme parks to offer half-price entry in exchange for used plastic bottles


Visitors to some of the UK’s most popular tourist attractions are to be offered half-price entry in exchange for used plastic drinks bottles, as part of a trial starting on Wednesday which gives instant incentives for recycling.
In a tie-up between theme park operator Merlin and drinks giant Coca-Cola, a series of so-called “reverse vending machines” will be installed outside the entrances of Alton Towers, Thorpe Park, Chessington World of Adventures and Legoland.
In a bid to boost flagging recycling rates and tackle plastic litter, the machines will reward users depositing any 500ml plastic bottle with half-price discount vouchers which can be redeemed at all 30 Merlin attractions in the UK.
The initiative – which will run until mid-October – follows research by Coca-Cola which reveals that 64% of Britons would recycle more if they were rewarded instantly for their actions.
At present, just 43% of the 13bn plastic bottles sold each year in the UK are recycled, and 700,000 are littered every day. Pressure is growing on the government, retailers and consumers to increase rates of plastic bottle recycling and cut marine pollution. In March, the environment secretary, Michael Gove, announced plans to launch a mandatory deposit system for bottles and cans in the UK, although details are still being worked out.
Conventional deposit return schemes – in operation in 38 countries – typically involve an upfront deposit which is refunded to consumers who return their bottles and cans. Fees vary depending on the size of the bottle or can and many increasingly use new “reverse vending machines” to automate the return.
“We want to reward people for doing the right thing by recycling their bottles and hope to encourage some people who wouldn’t otherwise have done so,” said Jon Woods, general manager of Coca-Cola UK & Ireland. “All of our bottles can be recycled and we want to get as many of them back as possible so they can be turned into new bottles and not end up as litter.”
Meanwhile, the Co-op – the first UK retailer to launch a deposit return scheme trial with reverse vending machines – is reporting positive feedback from thousands of visitors to major summer music festivals, with high take-up rates and reduced littering.

Mars (probably) has a lake of liquid water


A Mars orbiter has detected a wide lake of liquid water hidden below the planet’s southern ice sheets. There have been much-debated hints of tiny, ephemeral amounts of water on Mars before. But if confirmed, this lake marks the first discovery of a long-lasting cache of the liquid.
“This is potentially a really big deal,” says planetary scientist Briony Horgan of Purdue University in West Lafayette, Ind. “It’s another type of habitat in which life could be living on Mars today.”
The lake is about 20 kilometers across, planetary scientist Roberto Orosei of the National Institute of Astrophysics in Bologna, Italy and his colleagues report online July 25 in Science — but the water is buried beneath 1.5 kilometers of solid ice.
Orosei and colleagues spotted the lake by combining more than three years of observations from the European Space Agency’s orbiting Mars Express spacecraft. The craft’s MARSIS instrument, which stands for Mars Advanced Radar for Subsurface and Ionosphere Sounding, aimed radar waves at the planet to probe beneath its surface.
As those waves passed through the ice, they bounced off different materials embedded in the glaciers. The brightness of the reflection tells scientists about the material doing the reflecting — liquid water makes a brighter echo than either ice or rock.
Combining 29 radar observations taken from May 2012 to December 2015, MARSIS revealed a bright spot in the ice layers near Mars’ south pole, surrounded by much less reflective areas. Orosei and colleagues considered other explanations for the bright spot, such as radar bouncing off a hypothetical layer of carbon dioxide ice at the top of the sheet, but decided those options either wouldn’t produce the same radar signal or were too contrived to be physically likely.
That left one option: A lake of liquid water. Similar lakes beneath the ice in Antarctica and Greenland have been discovered in the same way (SN: 9/7/13, p. 26).
“On Earth, nobody would have been surprised to conclude that this was water,” Orosei says. “But to demonstrate the same on Mars was much more complicated.”
The lake is probably not pure water — temperatures at the bottom of the ice sheet are around –68° Celsius, and pure water would freeze there, even under the pressure of so much ice. But a lot of salt dissolved in the water could lower the freezing point. Salts of sodium, magnesium and calcium have been found elsewhere on Mars, and may be helping to keep this lake liquid (SN: 4/11/09, p. 12). The pool could also be more mud than water, but that could still be a habitable environment, Horgan says.
Previously, scientists have discovered extensive solid water ice sheets under the Martian dirt (SN Online: 1/11/18). There were also hints that liquid water flowed down cliff walls (SN: 10/31/15, p. 17), but those may turn out to be tiny dry avalanches. The Phoenix lander saw what looked like frozen water droplets at its site near the north pole in 2008, but that water may have been melted by the lander itself (SN Online: 9/9/10).
“If this [lake] is confirmed, it’s a substantial change in our understanding of the present-day habitability of Mars,” says Lisa Pratt, NASA’s planetary protection officer.
Though the newly discovered lake’s depth is unclear, its volume still dwarfs any previous signs of liquid water on Mars, Orosei says. The lake has to be at least 10 centimeters deep for MARSIS to have noticed it. That means it could contain at least 10 billion liters of liquid water.
“That’s big,” Horgan says. “When we’ve talked about water in other places, it’s in dribs and drabs.”
Under-ice lakes on Mars were first suggested in 1987, and the MARSIS team has been searching since Mars Express began orbiting the Red Planet in 2003. It took the team more than a decade to collect enough data to convince themselves the lake was real.
For the first several years of observations, limitations in the spacecraft’s onboard computer forced the team to average hundreds of radar pulses together before sending the data back to Earth. That strategy sometimes cancelled out the lake’s reflections, Orosei says — on some orbits, the bright spot was visible, on others, it wasn’t.
In the early 2010s, the team switched to a new technique that let them store the data and send it back to Earth more slowly. Then in August 2015, months before the end of the observing campaign, the experiment’s principal investigator, Giovanni Picardi of the University of Rome Sapienza, died unexpectedly.
“It was incredibly sad,” Orosei says. “We had all the data, but we had no leadership. The team was in disarray.”
Finally discovering the lake is “a testament to perseverance and longevity,” says planetary scientist Isaac Smith of the Planetary Science Institute, who is based in Lakewood, Colo. “Long after everyone else gave up looking, this team kept looking.”
But there is still room for doubt, says Smith, who works on a different radar experiment on NASA’s Mars Reconnaissance Orbiter that has seen no sign of the lake, even in CT scan–like 3-D views of the poles. It could be that MRO’s radar is scattering off the ice in a different way, or that the wavelengths it uses don’t penetrate as deep into the ice. The MRO team will look again, and will also try to create a 3-D view from the MARSIS data. Having a specific spot to aim for is helpful, he says.
“I expect there will be debate,” Smith says. “They’ve done their homework. This paper is well earned. But we should do some more follow-up.”

Rising sea levels will soon destroy underground US internet cables, scientists warn

internet cables

Underground internet cables criss-crossing coastal regions will be inundated by rising seas within the next 15 years, according to a new study.
Thousands of miles of fibre optic cables are under threat in US cities like New York, Seattle and Miami, and could soon be out of action unless steps are taken to protect them.
The report, presented at a meeting of internet network researchers in Montreal, is among the first to reveal the damage a changing climate will cause for the network of cables and data centres that underpins so much of modern life.
What shocked computer scientist Professor Paul Barford and his colleagues most when they investigated the effect of rising tides on US cities was the speed at which the internet will be compromised.
“Most of the damage that’s going to be done in the next 100 years will be done sooner than later,” said Professor Barford, a researcher at the University of Wisconsin-Madison.
“That surprised us. The expectation was that we’d have 50 years to plan for it. We don’t have 50 years.”
Most of this infrastructure was constructed around 25 years ago along trails running parallel with highways and coastlines, with no thought given to how geography would alter as the climate changed
In their study, presented at the Applied Networking Research Workshop, the scientists combined a comprehensive map of the internet’s physical structure with projections of sea level rise produced by the US National Oceanic and Atmospheric Administration (NOAA).
The most at-risk stretches of cable were unsurprisingly those already close to sea level, meaning the slight increases predicted for the next few years will be enough to cover them.
The researchers estimated that in total more than 4,000 miles of buried fibre optic cable in the US will be submerged by 2033.
Massive underwater internet cables link North America with the rest of the world, and the landing points where these cables end will be submerged “in a short period of time”, according to Professor Barford.
While the large transoceanic cables are completely waterproof, the buried smaller fibre optic cables are not and if they are submerged there could be far-reaching impacts not only in the coastal US but potentially around the world.
Flooding in coastal cities has been acknowledged as a major threat, and many areas have already begun building hardy sea walls to prepare for the worst. Professor Barford said such preparations will go some way to protecting the internet, but will probably not be enough.
“The first instinct will be to harden the infrastructure,” said Professor Barford.
“But keeping the sea at bay is hard. We can probably buy a little time, but in the long run it’s just not going to be effective.”
Professor Barford said recent hurricanes and storm surges in the eastern US had already given a taste of the kind of flooding that is to come. He said this study should serve as a “wake-up call” that prompts a discussion about how to protect the world’s precious internet from climate change.

Acidic oceans cause fish to lose their sense of smell

sea bass

When carbon dioxide is absorbed by seawater carbonic acid is formed, making the water more acidic. Since the Industrial Revolution, oceanic CO2 has risen by 43% and is predicted to be two and a half times current levels by the end of this century.

Fish use their sense of smell (olfaction) to find food, safe habitats, avoid predators, recognize each other and find suitable spawning grounds. A reduction in their ability to smell therefore can compromise these essential functions for their survival.

The new study provides evidence that economically important species will be affected by elevated CO2, leaving fish vulnerable because it affects their ability to detect odours.

University of Exeter researcher Dr Cosima Porteus, who led the study, said: “Our study is the first to examine the impact of rising carbon dioxide in the ocean on the olfactory system of fish. First we compared the behaviour of juvenile sea bass at CO2 levels typical of today’s ocean conditions, and those predicted for the end of the century. Sea bass in acidic waters swam less and were less likely to respond when they encountered the smell of a predator. These fish were also more likely to “freeze” indicating anxiety.”

Experts at the University of Exeter, in collaboration with scientists from the Centre of Marine Sciences (CCMar, Faro, Portugal) and the Centre for Environment, Fisheries and Aquaculture Science (Cefas), also tested the ability of the sea bass’ nose to detect different smells. They did this by recording the activity in the nervous system while their nose was exposed to water with different levels of CO2 and acidity.

Dr Porteus added: “The sense of smell of sea bass was reduced by up to half in sea water that was acidified with a level of CO2 predicted for the end of the century. Their ability to detect and respond to some odours associated with food and threatening situations was more strongly affected than for other odours. We think this is explained by acidified water affecting how odorant molecules bind to olfactory receptors in the fish’s nose, reducing how well they can distinguish these important stimuli.

Scientists also studied how the elevated CO2 and acidity in the water affected the genes being expressed in the nose and brain of sea bass and found evidence for altered expression of many of those involved in sensing smells and processing of this information. Although only sea bass were used in the study, the processes involved in the sense of smell are common to many aquatic species and therefore the findings should apply very broadly.

Dr Porteus said: “I wanted to examine if fish had any ability to compensate for this reduced sense of smell, but found that instead of increasing the expression of genes for smell receptors in their nose they did the opposite, exacerbating the problem.”

Prof Rod Wilson from the University of Exeter also commented on the plight for fish in a higher CO2 future world: “Our intriguing results show that CO2 impacts the nose of the fish directly. This will be in addition to the impact of CO2 on their central nervous system function suggested by others previously, which proposed an impaired processing of information in the brain itself. It is not yet known how rapidly fish will be able to overcome these problems as CO2 rises in the future. However, having to cope with two different problems caused by CO2, rather than just one, may reduce their ability to adapt or how long this will take.”

Near-future carbon dioxide levels impair the olfactory system of a marine fish is published in the journal Nature Climate Change.

Researchers engineer bacteria to create fertilizer out of thin air


In the future, plants will be able to create their own fertilizer. Farmers will no longer need to buy and spread fertilizer for their crops, and increased food production will benefit billions of people around the world, who might otherwise go hungry.

These statements may sound like something out of a science fiction novel, but new research by Washington University in St. Louis scientists show that it might soon be possible to engineer plants to develop their own fertilizer. This discovery could have a revolutionary effect on agriculture and the health of the planet.
The research, led by Himadri Pakrasi, the Glassberg-Greensfelder Distinguished University Professor in the Department of Biology in Arts & Sciences and director of the International Center for Energy, Environment and Sustainability (InCEES); and Maitrayee Bhattacharyya-Pakrasi, senior research associate in biology, was published in the May/June issue of mBio.

Creating fertilizer is energy intensive, and the process produces greenhouse gases that are a major driver of climate change. And it’s inefficient. Fertilizing is a delivery system for nitrogen, which plants use to create chlorophyll for photosynthesis, but less than 40 percent of the nitrogen in commercial fertilizer makes it to the plant.

After a plant has been fertilized, there is another problem: runoff. Fertilizer washed away by rain winds up in streams, rivers, bays and lakes, feeding algae that can grow out of control, blocking sunlight and killing plant and animal life below.

However, there is another abundant source of nitrogen all around us. The Earth’s atmosphere is about 78 percent nitrogen, and the Pakrasi lab in the Department of Biology just engineered a bacterium that can make use of that atmospheric gas — a process known as “fixing” nitrogen — in a significant step toward engineering plants that can do the same.

The research was rooted in the fact that, although there are no plants that can fix nitrogen from the air, there is a subset of cyanobacteria (bacteria that photosynthesize like plants) that is able to do so. Cyanobacteria can do this even though oxygen, a byproduct of photosynthesis, interferes with the process of nitrogen fixation.

The bacteria used in this research, Cyanothece, is able to fix nitrogen because of something it has in common with people.

“Cyanobacteria are the only bacteria that have a circadian rhythm,” Pakrasi said. Interestingly, Cyanothece photosynthesize during the day, converting sunlight to the chemical energy they use as fuel, and fix nitrogen at night, after removing most of the oxygen created during photosynthesis through respiration.

The research team wanted to take the genes from Cyanothece, responsible for this day-night mechanism, and put them into another type of cyanobacteria, Synechocystis, to coax this bug into fixing nitrogen from the air, too.

To find the right sequence of genes, the team looked for the telltale circadian rhythm. “We saw a contiguous set of 35 genes that were doing things only at night,” Pakrasi said, “and they were basically silent during the day.”

The team, which also included research associate Michelle Liberton, former research associate Jingjie Yu, and Deng Liu manually removed the oxygen from Synechocystis and added the genes from Cyanothece. Researchers found Synechocystis was able to fix nitrogen at 2 percent of Cyanothece. Things got really interesting, however, when Liu, a postdoctoral researcher who has been the mainstay of the project, began to remove some of those genes; with just 24 of the Cyanothece genes, Synechocystis was able to fix nitrogen at a rate of more than 30 percent of Cyanothece.

Nitrogen fixation rates dropped markedly with the addition of a little oxygen (up to 1 percent), but rose again with the addition of a different group of genes from Cyanothece, although it did not reach rates as high as without the presence of oxygen.

“This means that the engineering plan is feasible,” Pakrasi said. “I must say, this achievement was beyond my expectation.”

The next steps for the team are to dig deeper into the details of the process, perhaps narrow down even further the subset of genes necessary for nitrogen fixation, and collaborate with other plant scientists to apply the lessons learned from this study to the next level: nitrogen-fixing plants.

Crops that can make use of nitrogen from the air will be most effective for subsistence farmers — about 800 million people worldwide, according to the World Bank — raising yields on a scale that is beneficial to a family or a town and freeing up time that was once spent manually spreading fertilizer.

Artificial Intelligence (AI) technology could help protect water supplies

artificial intelligence in water treatment

Researchers at the University of Waterloo have developed Artificial Intelligence (AI) software capable of identifying and quantifying different kinds of cyanobacteria, or blue-green algae, a threat to shut down water systems when it suddenly proliferates.

“We need to protect our water supplies,” said Monica Emelko, a professor of civil and environmental engineering and member of the Water Institute at Waterloo. “This tool will arm us with a sentinel system, a more rapid indication when they are threatened.

“The exciting piece is that we’ve shown testing utilizing AI can be done quickly and well. Now it’s time to work through all the possible scenarios and optimize the technology.”

The operational AI system uses software in combination with a microscope to inexpensively and automatically analyze water samples for algae cells in about one to two hours, including confirmation of results by a human analyst.

Current testing methods, which typically involve sending samples to labs for manual analysis by technicians, take one to two days. Some automated systems already exist as well, but they require extremely expensive equipment and supplies.

According to Emelko and collaborator Alexander Wong, a systems design engineering professor at Waterloo, the AI system would provide an early warning of problems since testing could be done much more quickly and frequently.

Moving forward, the goal is an AI system to continuously monitor water flowing through a microscope for a wide range of contaminants and microorganisms.

“This brings our research into a high-impact area,” said Wong. “Helping to ensure safe water through widespread deployment of this technology would be one of the great ways to really make AI count.”

The researchers estimate it may take two to three years to refine a fully commercial sample testing system for use in labs or in-house at treatment plants. The technology to provide continuous monitoring could be three to four years away.

“It’s critical to have running water, even if we have to boil it, for basic hygiene,” said Monica Emelko, a professor of civil and environmental engineering at Waterloo. “If you don’t have running water, people start to get sick.”

Adjunct engineering professor Chao Jin, doctoral student Jason Deglint and research associate Maria Mesquita are also collaborators.

A study on the research, Quantification of cyanobacterial cells via a novel imaging-driven technique with an integrated fluorescence signature, was recently published in the journal Scientific Reports.

MOF material offers selective, reversible and repeatable capture of toxic atmospheric gas

nitrogen dioxide

Led by the University of Manchester, an international team of scientists has developed a metal-organic framework material (MOF) that exhibits a selective, fully reversible and repeatable capability to remove nitrogen dioxide gas from the atmosphere in ambient conditions. This discovery, confirmed by researchers using neutron scattering at the Department of Energy’s Oak Ridge National Laboratory, could lead to air filtration technologies that cost-effectively capture and convert large quantities of targeted gases, including carbon dioxide and other greenhouse gases, to facilitate their long-term sequestration to help mitigate air pollution and global warming.

As reported in Nature Materials, the material denoted as MFM-300(Al) exhibited the first reversible, selective capture of nitrogen dioxide at ambient pressures and temperatures — at low concentrations — in the presence of moisture, sulfur dioxide and carbon dioxide. Despite the highly reactive nature of nitrogen dioxide, the MFM-300(Al) material proved extremely robust, demonstrating the capability to be fully regenerated, or degassed, multiple times without loss of crystallinity or porosity.

“This material is the first example of a metal-organic framework that exhibits a highly selective and fully reversible capability for repeated separation of nitrogen dioxide from the air, even in presence of water,” said Sihai Yang, one of the study’s lead authors and a lecturer in inorganic chemistry at Manchester’s School of Chemistry.

Professor Martin Schröder, another lead author from Manchester Chemistry, commented, “Other studies of different porous materials often found performance was degraded in subsequent cycles by the nitrogen dioxide, or that the regeneration process was too difficult and costly.”

As part of the research, the scientists used neutron scattering techniques at the Department of Energy’s Oak Ridge National Laboratory to confirm and precisely characterize how MFM-300(Al) captures nitrogen dioxide molecules.

“Neutrons can easily penetrate dense materials and they are sensitive to lighter elements, such as the hydrogen atoms inside the MFM, which enabled us to observe how the nitrogen dioxide molecules are confined within the nano-size pores,” said Timmy Ramirez-Cuesta, a co-author and coordinator for the chemistry and catalysis initiative at ORNL’s Neutron Sciences Directorate. “We benefitted from the extremely high sensitivity and quantitative data provided by the VISION vibrational spectroscopy instrument on ORNL’s 16-B beamline at the Spallation Neutron Source, which uses neutrons instead of photons to probe molecular vibrations.”

The ability to directly observe how and where MFM-300(Al) traps nitrogen dioxide is helping the researchers validate a computer model of the MOF gas separation process, which could help identify how to produce and tailor other materials to capture a variety of different gases.

“Computer modeling and simulation played critical roles in interpreting the neutron scattering data by helping us connect subtle changes in the vibrational spectra to interactions between the MFM-300 and trapped molecules,” said Yongqiang Cheng, an ORNL neutron scattering scientist and co-author. “Our goal is to integrate the model with experimental techniques to deliver results that are otherwise difficult to achieve.”

Capturing greenhouse and toxic gases from the atmosphere has long been a challenge, because of their relatively low concentrations and the presence of moisture in the air, which can negatively affect separating targeted gas molecules from other gases. Another challenge has been finding a practical way to release a captured gas for long-term sequestration, such as in underground depleted oil reservoirs or saline-filled rock formations. MOFs offer solutions to many of these challenges, which is why they are the subject of recent scientific investigations.

Air pollution contributes significantly to diabetes globally!


New research links outdoor air pollution — even at levels deemed safe — to an increased risk of diabetes globally, according to a study from Washington University School of Medicine in St. Louis and the Veterans Affairs (VA) St. Louis Health Care System. The findings raise the possibility that reducing pollution may lead to a drop in diabetes cases in heavily polluted countries such as India and less polluted ones such as the United States.

Diabetes is one of the fastest growing diseases, affecting more than 420 million people worldwide and 30 million Americans. The main drivers of diabetes include eating an unhealthy diet, having a sedentary lifestyle, and obesity, but the new research indicates the extent to which outdoor air pollution plays a role.

“Our research shows a significant link between air pollution and diabetes globally,” said Ziyad Al-Aly, MD, the study’s senior author and an assistant professor of medicine at Washington University. “We found an increased risk, even at low levels of air pollution currently considered safe by the U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO). This is important because many industry lobbying groups argue that current levels are too stringent and should be relaxed. Evidence shows that current levels are still not sufficiently safe and need to be tightened.”

While growing evidence has suggested a link between air pollution and diabetes, researchers have not attempted to quantify that burden until now. “Over the past two decades, there have been bits of research about diabetes and pollution,” Al-Aly said. “We wanted to thread together the pieces for a broader, more solid understanding.”
To evaluate outdoor air pollution, the researchers looked at particulate matter, airborne microscopic pieces of dust, dirt, smoke, soot and liquid droplets. Previous studies have found that such particles can enter the lungs and invade the bloodstream, contributing to major health conditions such as heart disease, stroke, cancer and kidney disease. In diabetes, pollution is thought to reduce insulin production and trigger inflammation, preventing the body from converting blood glucose into energy that the body needs to maintain health.
Overall, the researchers estimated that pollution contributed to 3.2 million new diabetes cases globally in 2016, which represents about 14 percent of all new diabetes cases globally that year. They also estimated that 8.2 million years of healthy life were lost in 2016 due to pollution-linked diabetes, representing about 14 percent of all years of healthy life lost due to diabetes from any cause. (The measure of how many years of healthy life are lost is often referred to as “disability-adjusted life years.”)