Thursday, November 19, 2020

Volcanic eruptions have more effect in summer

KING ABDULLAH UNIVERSITY OF SCIENCE & TECHNOLOGY (KAUST)

Research News

Detailed modeling of the effect of volcanic eruptions on the El Niño Southern Oscillation (ENSO) has shown that the climate response to these events depends on the timing of the eruption and the preceding conditions. The research, led by KAUST researchers Evgeniya Predybaylo and Georgiy Stenchikov, settles a long-standing debate about the role of volcanic eruptions in global climate perturbations.

"The ENSO is a feature of the tropical Pacific Ocean climate, with patterns of temperature, precipitation and wind that oscillate between warmer El Niño and cooler La Niña phases every two to seven years," explains Predybaylo. "Due to the vast size of the tropical Pacific, the ENSO controls the climate in many other parts of the globe and is responsible for droughts, floods, hurricanes, heat waves and other severe weather events. To evaluate these risks, it is essential to have proper projections and predictions of future ENSO behavior."

Climate modeling indicates that the ENSO is very sensitive to external perturbations, such as increased carbon dioxide in the atmosphere or volcanic eruptions. Even though major volcanic eruptions, like the Mount Pinatubo eruption in 1991, are known to have caused widespread cooling due to the reflection of solar radiation, such effects have been difficult to prove by modeling.

"There was previously no modeling consensus on how the Pacific Ocean responds to such climatologically large volcanic eruptions, with climate models predicting diverse and often contradictory responses," says Sergey Osipov from the research team.

Because the tropical Pacific climate is itself highly variable, the modeling needs to be performed carefully to separate the eruption-driven ocean response from random variations. This requires a large number of climate simulations using a model that can simulate both the radiative impact of volcanic eruptions and a realistic ENSO cycle. To achieve this, the team collaborated with Andrew Wittenberg from Princeton University, US, to run the CM2.1 climate model using KAUST's supercomputer.

"After running more than 6,000 climate simulations covering nearly 20,000 model years and analyzing the data," says Predybaylo, "we found that the ENSO response to stratospheric volcanic eruptions strongly depends on the seasonal timing of the eruption and the state of the atmosphere and ocean in the Pacific at the time."

In particular, the research showed that even very large eruptions seem to have little discernible effect on the ENSO in winter or spring, while summer eruptions almost always produce a strong climate response.

"The principles and techniques developed in our study could also be applied to various types of observational data and multimodel studies of future climate change, including the effects of global warming," says Predybaylo.


CAPTION

The Butterfly Effect: KAUST's model shows how volcanic eruptions can disrupt global climate by affecting the El Niño Southern Oscillation.


CAPTION

The team has developed a simulation of the Mount Pinatubo eruption in 1991. The blue shading represents sulfur dioxide, the white shading represents sulfate aerosols and the orange area represents volcanic ash.

CREDIT

© 2020 KAUST

Does air pollution affect mental health later in life?

WILEY

Research News

In a study of women aged 80 years and older, living in locations with higher exposures to air pollution was associated with increased depressive symptoms. The findings are published in the Journal of the American Geriatrics Society.

When looking at individual air pollutants, a team led by investigators from of the University of Southern California found that long-term exposure to nitrogen dioxide or fine particulate air pollution was associated with increased depressive symptoms, but with only a small effect. Results also suggested that depressive symptoms might play a role in linking long-term air pollution exposure to memory decline more than 10 years after the exposure.

"This is the first study showing how air pollution exposures affect depressive symptoms as well as the interrelationship between the symptoms and subsequent memory decline that had not been found in older people aged less than 80 years," said lead author Andrew Petkus, PhD.

Senior author Jiu-Chiuan Chen, MD, ScD, added, "We know late-life exposures to ambient air pollutants accelerate brain aging and increase the dementia risk, but our new findings suggest the oldest-old populations may respond to air pollution neurotoxicity in a different way that needs to be investigated further."

Does air pollution increase women's risk of dementia?

Study finds high levels associated with brain shrinkage patterns common in Alzheimer's

AMERICAN ACADEMY OF NEUROLOGY

Research News

MINNEAPOLIS - Older women who live in locations with higher levels of air pollution may have more brain shrinkage, the kind seen in Alzheimer's disease, than women who live in locations with lower levels, according to a new study published in the November 18, 2020, online issue of Neurology®, the medical journal of the American Academy of Neurology. The study looked at fine particle pollution and found that breathing in high levels of this kind of air pollution was linked to shrinkage in the areas of the brain vulnerable to Alzheimer's disease.

Fine particle pollution consists of microscopic particles of chemicals, smoke, dust and other pollutants suspended in the air. They are no larger than 2.5 micrometers, 30 times smaller than the width of a human hair.

"Smaller brain volume is a known risk factor for dementia and Alzheimer's disease, but whether air pollution alters brain structure is still being researched," said study author Diana Younan, Ph.D., of the University of Southern California in Los Angeles. "Our study found that women in their 70s and 80s who were exposed to the higher levels of air pollution had an increased risk of brain changes linked to Alzheimer's disease over five years. Our research suggests these toxins may disrupt brain structure or connections in the brain's nerve cell network, contributing to the progression toward the disease."

The study involved 712 women with an average age of 78 who did not have dementia at the start of the study. Participants provided health histories as well as information on race/ethnicity, education, employment, alcohol use, smoking and physical activity. All women received MRI brain scans at the start of the study and five years later.

Researchers used the residential addresses of each participant to determine their average exposures to air pollution in the three years before the first MRI scan. They then divided participants into four equal groups. The lowest group was exposed to an average of 7 to 10 micrograms of fine particle pollution per cubic meter of air (μg/m3). The highest group was exposed to an average of 13 to 19 μg/m3. The U.S. Environmental Pollution Agency (EPA) considers average yearly exposures up to 12 μg/m3 to be safe.

Researchers used a machine learning tool to measure signs of Alzheimer's disease in the brain, a tool that had been trained to identify patterns of brain shrinkage specific to an increased risk of Alzheimer's disease by reading the brain scans of people with the disease.

Participants' MRI brain scans at the start of the study and five years later were assigned scores based on how similar they were to Alzheimer's disease patterns identified by the machine learning tool, specifically brain changes in regions found to be vulnerable to Alzheimer's disease. Scores ranged from zero to one, with higher scores showing more brain changes. Overall, the women's scores changed from 0.28 at the start of the study to 0.44 five years later.

For each 3 μg/m3 increase in air pollution exposure levels, researchers found a broader range of scores between the two scans and an average increase of 0.03, showing a greater extent of brain shrinkage over five years, which was equivalent to a 24% increased risk of Alzheimer's disease. The increases remained the same even after adjusting for age, education, employment, cardiovascular disease, high blood pressure, physical activity and other factors that could affect brain shrinkage.

"Our findings have important public health implications, because not only did we find brain shrinkage in women exposed to higher levels of air pollution, we also found it in women exposed to air pollution levels lower than those the EPA considers safe," said Younan. "While more research is needed, federal efforts to tighten air pollution exposure standards in the future may help reduce the risk of Alzheimer's disease in our older populations."

Limitations of the study include that it only looked at the brains of older women, so results may not be the same for men or younger women. It also examined only regional fine particle pollution, not other sources of pollution such as traffic emissions. Researchers were also not able to estimate participants' exposure to fine particle pollution in middle-age and young adulthood due to nationwide data not being available for those years.

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The study was supported by the National Institute on Aging.

Learn more about dementia at BrainandLife.org, home of the American Academy of Neurology's free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life® on Facebook, Twitter and Instagram.

When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.

The American Academy of Neurology is the world's largest association of neurologists and neuroscience professionals, with over 36,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, concussion, Parkinson's disease and epilepsy.

For more information about the American Academy of Neurology, visit AAN.com or find us on Facebook, Twitter, Instagram, LinkedIn and YouTube.


 

Which particulate air pollution poses the greatest health risk?

PAUL SCHERRER INSTITUTE

Research News

Researchers at the Paul Scherrer Institute PSI, together with colleagues from several other European institutions, have investigated whether particulate matter from certain sources can be especially harmful to human health. They found evidence that the amount of particulate matter alone is not the greatest health risk. Rather, it could be the so-called oxidative potential that makes particulate pollution so harmful. They are publishing their results today in the scientific journal Nature.

Particulate matter is one of the greatest health risks stemming from air pollution and, according to several studies, it is responsible for several million deaths each year. This means that poor air quality and particulate matter are among the five most important health risk factors, alongside high blood pressure, smoking, diabetes, and obesity. What makes particulate pollution so dangerous, however, is not yet precisely known. Together with an international collaborative team, researchers at the Paul Scherrer Institute PSI have now found out that the amount of particulate pollution is not the only decisive factor when it comes to health risks.

Oxidative potential of particulate matter as a health risk

"In this study we were primarily interested in two points", says Kaspar Dällenbach from the gas-phase and aerosol chemistry research group at PSI. "First, which sources in Europe are responsible for the so-called oxidative potential of particulate matter (also known as aerosols) and, second, whether the health risk from this particulate matter is caused by its oxidative potential."

Here the term "oxidative potential" refers to the ability of particulate matter to reduce the amount of antioxidants, which can lead to damage in cells and tissues of the human body. In a first step, the researchers exposed cells from the human airways, so-called bronchial epithelial cells, to particulate samples and tested their biological reaction. When these cells are under stress, they give off a signalling substance for the immune system, which initiates inflammatory reactions in the body. The researchers were able to show that particulate matter with an elevated oxidative potential intensifies the cells' inflammatory reaction. This suggests that the oxidative potential determines how harmful the particulate matter is. The causal connection between elevated oxidative potential and a danger to health still has not been definitely established, according to Dällenbach. "But the study is another clear indication that this connection actually does exist."

A partner study led by the University of Bern showed that the cells of patients who suffer from a special pre-existing illness, cystic fibrosis, exhibit a weakened defense against particulate matter. While in healthy cells an antioxidant defense mechanism was able to stop the progression of the inflammatory reaction, the defense capacity in sick cells was insufficient. This led to increased cell mortality.

Where does particulate matter and their oxidative potential come from?

In addition, the researchers collected particulate samples at various locations in Switzerland. Using a mass spectrometry technique developed at PSI, they analysed the composition of the particulate matter. The chemical profile obtained in this way for each particulate sample indicates the sources from which it originates. Furthermore, colleagues in Grenoble determined the oxidative potential of the same samples in order to get an indication of the danger to human health. With the help of detailed analyses and statistical methods, the researchers then determined the oxidative potential for all relevant emission sources. On the basis of these experimental data, they used a computer model to calculate the locations in Europe with the highest oxidative potential due to particulate matter throughout the year, and they identified mainly metropolitan areas such as the French capital Paris and the Po Valley in northern Italy as critical regions.

"Our results show that the oxidative potential of particulate matter and the amount of particulate matter are not determined by the same sources", Dällenbach sums up. The largest portion of particulate matter consists of mineral dust and so-called secondary inorganic aerosols, such as ammonium nitrate and sulphate. The oxidative potential of particulate matter, on the other hand, is primarily determined by so-called anthropogenic secondary organic aerosols, which come mainly from wood combustion, and by metal emissions from brake and tire wear in road traffic. The researchers found not only that the population in urban areas is exposed to a higher amount of particulate matter, but also that this particulate matter in these regions has a higher oxidative potential and is therefore more harmful to health than particulate pollution in rural areas. "Our results show that regulating the amount of particulates alone might not be effective", says Dällenbach. In addition, the study by the University of Bern suggests that population groups with pre-existing illnesses could especially benefit from appropriate measures to reduce particulate matter pollution.

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Text: Paul Scherrer Institute/Sebastian Jutzi

About PSI

The Paul Scherrer Institute PSI develops, builds and operates large, complex research facilities and makes them available to the national and international research community. The institute's own key research priorities are in the fields of matter and materials, energy and environment and human health. PSI is committed to the training of future generations. Therefore about one quarter of our staff are post-docs, post-graduates or apprentices. Altogether PSI employs 2100 people, thus being the largest research institute in Switzerland. The annual budget amounts to approximately CHF 407 million. PSI is part of the ETH Domain, with the other members being the two Swiss Federal Institutes of Technology, ETH Zurich and EPFL Lausanne, as well as Eawag (Swiss Federal Institute of Aquatic Science and Technology), Empa (Swiss Federal Laboratories for Materials Science and Technology) and WSL (Swiss Federal Institute for Forest, Snow and Landscape Research).

Original publication

Sources of particulate matter air pollution and its oxidative potential in Europe
Kaspar Rudolf Daellenbach et al.
Nature, 18.11.2020
DOI: 10.1038/s41586-020-2902-8

Original publication of the partner study

Z. Leni et al., Oxidative stress-induced inflammation in susceptible airways by anthropogenic aerosol. PLOS ONE, 19.11.2020
DOI: 10.1371/journal.pone.0233425.

 

Air pollution costs Utahns billions annually and shortens life expectancy by two years

New study reveals the cost of air pollution for Utahns' health and pocketbooks

UNIVERSITY OF UTAH

Research News

Air pollution has been a problem in Utah since before the territory was officially recognized as a state. The mountain valleys of this high elevation region are particularly vulnerable to the buildup of air pollution from vehicles, household heating and power production. Together with high per-capita energy use, this has resulted in periods of poor air quality. However, with so many types of pollution and regional conditions, determining the overall effects of air pollution on Utah's health and economy has been a major challenge. A new study from 23 Utah-based researchers, including five from the University of Utah, sought to do just that.

The study estimated that air pollution shortens the life of the average Utahn by around 2 years. And pollution costs Utah's economy around $1.9 billion annually. But many state-level actions, such as increasing vehicle and building efficiency, could reduce air pollution by double-digit percentages while benefitting the economy, the researchers found.

The team used an approach called expert assessment, which combines all available research and experience from published and unpublished scientific studies. Combining expertise from public health, atmospheric science and economics, the researchers assessed what types of disease and economic harm could stem from Utah's air pollution. The study was published in the peer-reviewed journal Atmosphere in a special issue on air quality in Utah.

They estimated that air pollution in Utah causes between 2,500 and 8,000 premature deaths each year, decreasing the median life expectancy of Utahns by 1.1 to 3.6 years. This loss of life expectancy is distributed across most of the population, they found, rather than only affecting "sensitive groups." For example, 75% of Utahns may lose 1 year of life or more because of air pollution and 23% may lose 5 years or more.

This substantial health burden is caused by many illnesses and conditions that most people might not associate with air pollution. For example, exposure to particulates and other pollutants increases occurrence of heart and lung diseases, including congestive heart failure, heart attack, pneumonia, COPD and asthma. These conditions account for 62% of the pollution impact on health, according to this study. The remaining 38% of health effects are associated with stroke, cancer, reproductive harm to mothers and children, mental illness, behavioral dysfunction, immune disease, autism and other conditions--all exacerbated by exposure to dirty air.

On the economic side, the researchers estimated that the direct and indirect costs of air pollution cost Utahns around $1.9 billion dollars (in the range of $0.75-3.3 billion) annually. This economic damage results from direct effects such as healthcare expenses, damage to crops and lost earning potential, in addition to indirect costs such as loss of tourism, decreased growth and regulatory burdens.

"It was a real eye-opener to see quantitative estimates of how serious the health and economic costs of air pollution are for the people of Utah," said Isabella Errigo, lead author and a graduate student at Brigham Young University. "The consequences of dirty air can seem very abstract until you read the medical research connecting the quality of our environment to our personal health."

Even though the estimates of cost in this study are on the low end of national estimates, which range up to $9 billion a year for Utah, they are still much higher than figures commonly discussed in the legislature. For example, approximately $10 million was appropriated to clean Utah's air this year, representing only 0.1% to 0.5% of the costs of air pollution.

"Utahns understand that air pollution imposes large hidden costs on our communities which is why it's consistently ranked as a top concern," said Logan Mitchell, a research assistant professor at the U and a co-author of the study. "Thankfully, innovation has made clean energy technologies cost competitive on the market, without even considering those hidden costs. The coming energy transition will mean being good stewards of the environment will also protect our economy."

The mismatch between the size of the problem and the proposed solutions emphasizes one of the central findings from the study: cleaning the air could have immense health and economic benefits for Utah. The authors combined their estimates of cost with the air pollution goals from the recent Utah Roadmap to Clean Air, produced by the U's Kem C. Gardner Policy Institute. If Utah achieves the roadmap's pollution reduction targets, they estimate, Utah could save $500 million per year by 2030 and $1.1 billion per year by 2050.

"The payoff of reducing pollution would be huge in economic terms and the benefits would be incalculable in terms of human life and health," said senior author Ben Abbott, an assistant professor at BYU. "It's a question of choice. Are we going to settle for incremental progress in air quality or take advantage of this immense opportunity to improve the health of our communities and remove this enormous drag on our economy?"

"When I read these results, my thoughts immediately turn to my friends and family who live in Utah," said co-author Rebecca Frei, a graduate student at the University of Alberta. "My grandmother goes walking and my niece plays on the playground every day. Changing some simple things about how we operate means added years of life. To me, that's a no-brainer. This isn't about pushing an agenda, this is about assessing the evidence and acting out of love for our families and community."

The researchers ranked more than 30 recommendations of how to best reduce the amount of air pollution in Utah. At the top of the list: increase efficiency of vehicles and buildings, invest in awareness, remove subsidies for nonrenewable energy, require payment for pollution and expand alternative transportation. They estimated that each of these interventions could result in double-digit decreases in air pollution. The researchers suggested that changes at the state level and community level as the most effective and tractable.

The researchers cautioned that no single change would achieve the desired improvement in air quality alone. "We need long-term implementation of proven pollution control measures," Errigo said. "It's going to take commitment from multiple groups at city to state levels to clean up our air and prepare for future growth."

The findings of this study are directly in line with the recommendations of the Utah Road Map to Clean Air and add quantitative estimates of the health and economic costs. The researchers hope that these estimates provide additional context for state legislators and concerned citizens who want to enact positive change.

"In our efforts to clear the air there are no perfect answers, but there are practical solutions," said Thom Carter, Executive Director of the Utah Clean Air Partnership (UCAIR) and co-author on the study. "When looking at how poor air quality impacts our region, it is important to know that we are making progress and that each person, family, organization, and community can find ways to reduce emissions and improve our quality of life."

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Find the full study here.

Other co-authors include Daniel Mendoza, Kerry Kelly, Andrew Freeman and Heather Holmes from the U; Sayedeh Sara Sayedi, Jeffrey Glenn, John D. Beard, Samuel Bratsman, Robert A. Chaney, Mitchell Greenhalgh, James D. Johnston, Leslie Lange and Audrey Stacey from BYU;  Peter D. Howe, Randal Martin and Trang Tran from Utah State University; Andrew Follett from Yale Law School and Derrek Wilson from the University of Colorado, Boulder Law School.

Disclaimer: AAAS a

These Items in Your Home Are Harming America’s Sea Animals

A new report examines how plastic waste affects marine wildlife.


Hawaiian monk seals are one of more than a dozen species at risk of extinction that had ingested or were tangled in plastic.
Credit...Paulo Oliveira/Alamy


By Catrin Einhorn
Nov. 19, 2020, NYT


How severely the world’s plastic waste crisis is affecting marine wildlife is not fully understood, despite decades of research and gruesome images of whales’ bellies filled with plastic and a turtle with a straw lodged in its nostril. A new report by Oceana, a conservation group, illustrates some of what we know about how plastic affects sea turtles and marine mammals in United States waters.
The findings offer a glimpse of a larger problem.

The authors focused on sea turtles and marine mammals for practical reasons. These animals are federally protected, so when they are found in distress or wash up dead on a beach, responders are required to document it. By collecting data from government agencies and marine life organizations around the country, the authors found almost 1,800 cases of plastic entanglement or ingestion affecting 40 species since 2009.

But the report notes that the number is “a gross underestimate” because humans observe a tiny fraction of animal deaths in the ocean. Even so, of the nation’s 23 coastal states, it found cases in 21.

“This is the first time we’re looking at the problem from a U.S. perspective,” said Kimberly Warner, the report’s author and a senior scientist at Oceana. “This brings the problem home.”


In 2016, the United States produced more plastic waste than any other nation, and more of that plastic entered the ocean than previously thought, according to a recent study. As of 2015, less than a tenth of the world’s cumulative plastic waste had been recycled.

The Oceana report found that in the reported cases, 90 percent of the animals had swallowed plastic, and the rest were entangled in it. Necropsies often showed that the animals had died from blockages or lacerations. Other times, ingesting plastic may have simply weakened the animal or played no role in its death. Overall, in 82 percent of the cases, the animals died.


The culprits go beyond the usual suspects.

In the 1980s, environmental activists warned of the devastating effects of six-pack rings ensnaring sea animals. People started dutifully cutting them before disposal, and in 1994 the Environmental Protection Agency mandated that six-pack rings must be degradable, though the process may take months. Consumers have also been warned about releasing balloons, which can harm marine animals.

Recently some municipalities, counties and states have banned single-use plastic bags, one of the biggest contributors to ingestion and entanglements, according to the report. Plastic packing straps were found constricting the necks or bodies of seals and sea lions, naturally curious animals who may have gotten entangled while trying to play. Manatees ingested lots of fishing line.

But the report also found many more surprising items caused harm. Along the Gulf Coast, mesh produce bags were found in the guts of sea turtles and also entangling their bodies. In 2015, a loggerhead turtle in Georgia was found with a toothbrush and fork in its digestive tract, among other items. Two years later, another turtle was found in New York with a plastic dental flosser inside it. Food wrappers, sandwich bags, sponges, and even decorative plastic Easter grass were among the items discovered. A bottlenose dolphin in North Carolina had its head stuck in the hole of a flying disc. In Virginia, a DVD case lacerated the stomach of a sei whale.



A dead Laysan albatross chick on Midway Atoll in the Pacific.
Paulo Oliveira/Alamy

Many of the victims are endangered or threatened.

More than a dozen species at risk of extinction — including sea turtles, Hawaiian monk seals and sei whales — ingested or were tangled in plastic. Manatees, those gentle, slow-moving giants that graze on seagrass, made up 700 cases. The report quotes Brandon Bassett, a biologist at the Florida Fish and Wildlife Conservation Commission, describing part of what he found inside one dead manatee: “Imagine a ball of plastic bags in the stomach, about the size of a cantaloupe, and then a bunch of plastic bags that were wrapped and almost like a rope that was about 3 feet long.”

Scientists are learning more about why animals consume plastic. To sea turtles, a floating plastic bag may resemble a jellyfish meal, but that doesn’t explain the bottle caps and hard plastic shards found in their digestive tracts or stool. One study suggested that plastic starts to smell appetizing as it becomes coated in algae and microorganisms.

In South Carolina, one ailing loggerhead passed almost 60 pieces of plastic through its digestive system during its rehabilitation at a sea turtle center. Juveniles are more at risk because of their size and undeveloped gastrointestinal tract. More than 20 percent of the sea turtles that had ingested plastic were just months old. Some were only a few days old. A recent Australian study found that just 14 pieces of plastic in their digestive tracts significantly increased sea turtles’ risk of death.

Still, plastic waste is not the biggest killer of marine life.

Humans have created all kinds of dire problems for sea animals: rising sea temperatures, fishermen hauling in unintended species, ship striking them, other marine pollution and habitat degradation.

“Plastic in and of itself may not be as big of a threat as we’re led to believe,” said Jesse Senko, an assistant research professor and senior sustainability scientist at Arizona State University. “The scientific community has not done a good enough job of really assessing these questions, looking beyond how it affects an individual animal.”


A green sea turtle on a debris-filled beach in Midway Atoll.
Credit...Caleb Jones/Associated Press

He believes that images of decomposing sea birds with bellies full of plastic lead the public and media to focus on plastic even when other threats are more significant.

Ultimately, plastics and rising sea temperatures are connected; after all, the vast majority of plastic is derived from fossil fuels.

The Oceana report calls on national, state and local governments to restrict the production of single-use plastics and it asks companies to offer consumers plastic-free options.

“I’m old enough to remember a time when it didn’t permeate everything in my life,” Dr. Warner said. “And yet it’s built up at an alarming rate.

Japan faces another Fukushima disaster crisis

Collecting sea water samples near the damaged Fukushima nuclear power station.

 Image: By IAEA Imagebank, via Wikimedia Commons

A plan to dump a million tonnes of radioactive water from the Fukushima disaster off Japan is alarming local people.

LONDON, 3 November, 2020 − The Japanese government has an unsolvable problem: what to do with more than a million tonnes of water contaminated with radioactive tritium, in store since the Fukushima disaster and growing at more than 150 tonnes a day.

The water, contained in a thousand giant tanks, has been steadily accumulating since the nuclear accident in 2011. It has been used to cool the three reactors that suffered a meltdown as a result of the tsunami that hit the coast.

Tritium is a radioactive element produced as a by-product by nuclear reactors under normal operation, and is present everywhere in the fabric of the reactor buildings, so water used for cooling them is bound to be contaminated by it.

To avoid another potentially catastrophic meltdown in the remaining fuel the cooling has to continue indefinitely, so the problem continues to worsen. The government has been told that Japan will run out of storage tanks by 2022.

Announcement delayed

As often happens when governments are faced with difficult problems, the unpalatable decision to release the contaminated water into the sea has not been formally announced, but the intention of the government to take this course has been leaked and so widely reported.

Immediately both local and worldwide adverse reaction has resulted. There are the direct effects on the local fishermen who fear that no one will want to buy their catch, but over a wider area the health effects are the main concern.

As ever with the nuclear industry, there are two widely different views on tritium. The Health Physics Society says it is a mildly radioactive element that is present everywhere, and doubts that people will be affected by it. But the Nuclear Information and Resource Service believes tritium is far more dangerous and increases the likelihood of cancers, birth defects and genetic disorders.

The issue is further complicated because the Fukushima wastewater contains a number of other radionuclides, not in such high quantities, but sufficient to cause damage. Ian Fairlie, an independent consultant on radioactivity in the environment, is extremely concerned about Japan’s plans and the health of the local people.

“Ten half-lives for tritium is 123 years: that’s how long these tanks will have to last – at least. This will allow time also for politicians to reflect on the wisdom of their support for nuclear power”

In a detailed assessment of the situation he says other highly dangerous radioactive substances, including caesium-137 and strontium-90, are also in the water stored at Fukushima.

They are in lower quantities than the tritium, he says, but still unacceptably high – up to 100 times above the legally permitted limit. All these radionuclides decay over time − some take thousands of years − but tritium decays faster, the danger from it halving every 12.3 years.

In a briefing for the Nuclear Free Local Authorities (NFLA), a UK based organisation, another independent analyst, Tim Deere-Jones, discusses research that shows that tritium binds with organic material in plants and animals.

This is potentially highly damaging to human health because it travels up the food chain in the marine environment, specifically accumulating in fish. This means fish-eating communities on the Japanese coast could ingest much larger quantities of tritium than some physicists think likely.

Relying on dilution

Tim Deere-Jones is also concerned that the tritium will be blown inshore on the prevailing wind in sea spray and will bio-accumulate in food plants, making it risky to eat crops as far as ten miles inland. Because of the potential dangers of releasing the water the NFLA has asked the Japanese government to reconsider its decision.

The government has not yet responded though, because officially it is still considering what to do. However, it is likely to argue that pumping the contaminated water into the sea is acceptable because it will be diluted millions of times, and anyway seawater does already contain minute quantities of tritium.

Dr Fairlie is among many who think this is too dangerous, but he admits there are no easy solutions.

He says: “Barring a miraculous technical discovery which is unlikely, I think TEPCO/Japanese Gov’t [TEPCO is the Tokyo Electric Power Company, owner of the Fukushima Daiichi plant]  will have to buy more land and keep on building more holding tanks to allow for tritium decay to take place. Ten half-lives for tritium is 123 years: that’s how long these tanks will have to last – at least.

“This will allow time not only for tritium to decay, but also for politicians to reflect on the wisdom of their support for nuclear power.” − Climate News Network


Australian forests’ smoke climbed 

20 miles in 2019

Near to Sydney, far from the fires, the smoke was still thick enough to obscure the sun. 

Image: By simonrumi (public domain), via Wikimedia Commons

Blazing Australian forests made their mark high in the stratosphere and cast a cloud that lingered for months.

LONDON, 4 November, 2020 − Australian forests, devoured by devastating wildfires in the last southern hemisphere summer, set a new high − a huge smoke cloud that soared more than 20 miles into the upper atmosphere and stayed there for months.

An international team of scientists reports in the Nature journal Communications Earth and Environment that they tracked the cloud to an altitude of 35 kilometres (21 miles).

They measured it as 1,000 kms (625 miles) across. They followed it around the planet for 66,000 kms (41,010 miles). And they confirm that it remained intact for three months.

This high-flying pollution wasn’t the first such instance: just three times the size of any observed predecessor. Until now the record was held by plumes soaring from forest fires in western Canada in 2017.

Growing intensity

“When I saw the satellite measurement of the smoke plume at 35 kms, it was jaw-dropping. I never would have expected that”, said Adam Bourassa of the University of Saskatchewan in Canada, one of the researchers.

“We’re seeing records broken in terms of the impact on the atmosphere from these fires. Knowing that they’re likely to strike more frequently and with more intensity due to climate change, we could end up with a pretty dramatically changed atmosphere.”

A blaze that can make a new cloud 35 kms above its surface is an indicator both of the potential devastation of climate change driven by profligate human use of fossil fuels and of the intricate workings of the biosphere and atmosphere.

After months of desperate drought in 2019, eastern Australia effectively caught fire. Around 110,000 sq kms of bush, forest and grassland went up in smoke: with them went thousands of homes and millions of wild and domestic animals. Altogether 33 people died.

“We’re seeing records broken in terms of the impact on the atmosphere from these fires … we could end up with a pretty dramatically changed atmosphere”

So huge and sustained were the fires, and so dense the smoke, that the fires began to generate their own thunderstorms, known as pyrocumulonimbus, to create powerful updrafts to carry the aerosols and soot far above the flight paths of the highest jet airliners.

Researchers from France, the UK and Canada used sensitive satellite readings to track the sustained smoke signal from a part-incinerated island: at altitude, it was still dense enough to absorb, scatter and weaken the sunlight falling on the Earth below.

“What was also really amazing was that as the smoke sits in the atmosphere, it starts to absorb sunlight and so it starts to heat up,” Professor Bourassa said.

“And then, because it’s getting hotter, it starts to rise in a swirling vortex bubble, and it just rose higher and higher through the atmosphere.” − Climate News Network