Duke scientists look deeper for coal ash hazards

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Coal-ash-hazards

Coal-ash-hazards

As the U.S. Environmental Protection Agency weighs whether to define coal ash as hazardous waste, a Duke University study identifies new monitoring protocols and insights that can help investigators more accurately measure and predict the ecological impacts of coal ash contaminants. “The take-away lesson is we need to change how and where we look for coal ash contaminants,” says Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment. “Risks to water quality and aquatic life don’t end with surface water contamination, but much of our current monitoring does.”

The study, published online this week in the peer-reviewed journal Environmental Science and Technology, documents contaminant levels in aquatic ecosystems over an 18-month period following a massive coal sludge spill in 2008 at a Tennessee Valley Authority power plant in Kingston, Tenn.

By analyzing more than 220 water samples collected over the 18-month period, the Duke team found that high concentrations of arsenic from the TVA coal ash remained in pore water — water trapped within river-bottom sediment — long after contaminant levels in surface waters dropped back below safe thresholds. Samples extracted from 10 centimeters to half a meter below the surface of sediment in downstream rivers contained arsenic levels of up to 2,000 parts per billion – well above the EPA’s thresholds of 10 parts per billion for safe drinking water, and 150 parts per billion for protection of aquatic life.

“It’s like cleaning your house,” Vengosh says of the finding. “Everything may look clean, but if you look under the rugs, that’s where you find the dirt.”

The potential impacts of pore water contamination extend far beyond the river bottom, he explains, because “this is where the biological food chain begins, so any bioaccumulation of toxins will start here.”

The research team, which included two graduate students from Duke’s Nicholas School of the Environment and Pratt School of Engineering, also found that acidity and the loss or gain of oxygen in water play key roles in controlling how arsenic, selenium and other coal ash contaminants leach into the environment. Knowing this will help scientists better predict the fate and migration of contaminants derived from coal ash residues, particularly those stored in holding ponds and landfills, as well as any potential leakage into lakes, rivers and other aquatic systems.

The study comes as the EPA is considering whether to define ash from coal-burning power plants as hazardous waste. The deadline for public comment to the EPA was Nov. 19; a final ruling — what Vengosh calls “a defining moment” — is expected in coming months.

“At more than 3.7 million cubic meters, the scope of the TVA spill is unprecedented, but similar processes are taking place in holding ponds, landfills and other coal ash storage facilities across the nation,” he says. “As long as coal ash isn’t regulated as hazardous waste, there is no way to prevent discharges of contaminants from these facilities and protect the environment.”

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Soil microbes define dangerous rates of climate change

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Soil-microbes-define

The rate of global warming could lead to a rapid release of carbon from peatlands that would further accelerate global warming. Two recent studies published by the Mathematics Research Institute at the University of Exeter highlight the risk that this ‘compost bomb’ instability could pose, and calculate the conditions under which it could occur.

The same Exeter team is now exploring a possible link between the theories described in the studies and last summer’s devastating peatland fires in Russia.

The first paper is published in the European Journal of Social Science and the second in Proceedings of the Royal Society A.

The first paper by Catherine Luke and Professor Peter Cox describes the basic phenomenon. When soil microbes decompose organic matter they release heat – this is why compost heaps are often warmer than the air around them.

The compost bomb instability is a runaway feedback that occurs when the heat is generated by microbes more quickly than it can escape to the atmosphere. This in turn requires that the active decomposing soil layer is thermally-insulated from the atmosphere.

Catherine Luke explains: “The compost bomb instability is most likely to occur in drying organic soils covered by an insulating lichen or moss layer”.

The second paper led by Dr Sebastian Wieczorek and Professor Peter Ashwin, also of the University of Exeter, proves there is a dangerous rate of global warming beyond which the compost bomb instability occurs.

This is in contrast to the general belief that tipping points correspond to dangerous levels of global warming.

Sebastian Wieczorek explains: “The compost bomb instability is a novel type of rate-dependent climate tipping point”.

The Exeter team is now modelling the potential impact of the compost bomb instability on future climate change, including the potential link to the Russian peatland fires.It is also working to identify other rate-dependent tipping points.

Air above Dead Sea contains very high levels of oxidized mercury

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Air above Dead

Air above Dead

Measurements show that the sea’s salt has profound effects on the chemistry of the air above its surface. The atmosphere over the Dead Sea, researchers have found, is laden with oxidized mercury. Some of the highest levels of oxidized mercury ever observed outside the polar regions exist there.

The results appear in a paper published on-line November 28th in the journal Nature Geoscience.

In the research, funded by the National Science Foundation (NSF), scientist Daniel Obrist and colleagues at the Desert Research Institute in Reno, Nevada, and at Hebrew University in Isreal measured several periods of extremely high atmospheric oxidized mercury.

Mercury exists in the atmosphere in an elemental and in an oxidized state. It’s emitted by various natural and human processes, and can be converted in the atmosphere between these forms.

High levels of oxidized mercury are a concern, says Obrist, because this form is deposited quickly in the environment after its formation.

Atmospheric mercury deposition is the main way mercury, a potent neurotoxin, finds its way into global ecosystems.

After it’s deposited, mercury can accumulate through the food chain where it may reach very high levels. “These levels are of major concern to humans,” says Obrist, “especially in the consumption of mercury-laden fish.”

Fish caught in oceans are the main source of mercury intake in the U.S. population.

Observations of high naturally-occurring oxidized mercury levels had been limited to the polar atmosphere. There, oxidized mercury is formed during a process called atmospheric mercury depletion events.

During mercury depletions, elemental mercury is converted to oxidized mercury, which is then readily deposited on surfaces.

These events may increase mercury loads to sensitive arctic environments by hundreds of tons of mercury each year.

Now, Obrist says, “we’ve found near-complete depletion of elemental mercury–and formation of some of the highest oxidized mercury levels ever seen–above the Dead Sea, a place where temperatures reach 45 degrees Celsius.”

Such pronounced mercury depletion events were unexpected outside the frigid poles. High temperatures were thought to impede this chemical process.

“Elemental mercury is somewhat resistant to oxidation, so it’s been difficult to explain levels of oxidized mercury measured in the atmosphere outside polar regions,” says Alex Pszenny, director of NSF’s Atmospheric Chemistry Program, which funded the research. “These new results provide an explanation.”

The mechanisms involved in the conversion of mercury above the Dead Sea appear similar, however, to those in polar regions: both start with halogens.

Halogens, or halogen elements, are non-metal elements such as fluorine, chlorine, bromine and iodine.

Observations and modeling results indicate that at the Dead Sea, the conversion of elemental mercury is driven by bromine.

The new results show that bromine levels observed above oceans may be high enough to initiate mercury oxidation.

“We discovered that bromine can oxidize mercury in the mid-latitude atmosphere,” says Obrist, “far from the poles. That points to an important role of bromine-induced mercury oxidation in mercury deposition over the world’s oceans.”

What goes into the ocean, he says, may eventually wind up in its fish. And in those who eat them.

Research highlights the ‘human face’ of climate change

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Research-highlights

Five years of social science research in Canada’s arctic has taught one University of Guelph geography professor a thing or two about climate change’s “human face.” Barry Smit is the Canada Research Chair in Global Environmental Change, and since 2005 he’s studied how Arctic communities have tried to adapt to the rising temperatures caused by major shifts in global weather patterns.

The human dimension of climate change has long been understudied, says Smit, who is taking part this week in a panel discussion on the environment and economy at the first ever Canada Research Chairs conference in Toronto.

Over the course of two research projects – one with ArcticNet and another with the International Polar Year project – Smit has seen first-hand how Canada’s Inuit have dealt with changing ice levels, wind speed, migration routes, and so on.

“It’s already affecting the people who live there,” says Smit about the impact of global warming.

“And they’re having to figure out ways of adapting their livelihoods to face the changes caused by these changing conditions.”

Some communities are seeing their dietary patterns evolve because the animals they’ve traditionally hunted have shifted their migratory patterns, says Smit. That shift has caused those communities to rely on grocery stores for their food – and since the groceries found in Canada’s arctic are often no better than “what we in the south would generally characterize as junk food,” that’s led to teeth problems and higher rates of diabetes, says Smit.

Part of the goal of his research, says Smit, is to challenge the idea that physical and social environments are completely unrelated. That’s certainly not true, he says, if you look at how many Inuit relate to the ice they live on.

“The ice is their highway. And one of the thing they’ve noticed is that their highway is collapsing in places its never collapsed before,” he says.

Smit’s work has involved partnerships not only with researchers from other Arctic countries but also stakeholders in the communities themselves. His team’s research, he says, has been incorporated into the communities’ day-to-day decision-making – in the setting of hunting quotas, for instance, or in the construction of buildings on the melting permafrost.

And he points out that the research isn’t just a one-way exchange, one where his team bestows its wisdom upon the Arctic communities. Instead, the Inuit communities have helped refine his own research – by pointing out, for example, that it’s not so much the warmer temperatures that create the most significant social problems, but the changing winds that move the ice to places it’s never been before.

Smit has also been involved with similar research into the relationship between social and environmental outcomes in Chile and Ghana. He adds that he’s working on a co-operative project with researchers and community members in the South Pacific and on Haida Gwaii off the coast of British Columbia to study the social impact of rising ocean levels.

All that work, he says, is concerned with bringing about a more “holistic analysis” of climate change.

“The human face of climate change isn’t often recognized,” he says.

Location, location, location: Some coral reefs less vulnerable to rising sea temperatures

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Some-coral-reefs-less

New research highlighting coastal locations where coral can better withstand rising sea temperatures, a leading cause of stress to coral reefs, may guide efforts to conserve the largest living structures on Earth. The findings hold promise for an estimated 100 million people living along the coasts of tropical developing countries whose livelihoods and welfare depend directly on coral reefs, but are currently under threat from climate change.

In a report published in an online edition of Ecology Letters today, scientists from Australia, the UK, Mexico and the US, mapped coral stress across the Bahamas in the Caribbean and found that sea temperatures, which strongly influence coral health, caused less stress to reefs in certain areas.

This discovery was borne out in the second half of the study, during which the researchers designed marine reserves best-suited to four possible scenarios of how coral would respond to further sea temperature rises. In each hypothetical scenario, 15 per cent of the locations in the Bahamas were consistently selected.

While the study’s lead author, Professor Peter J. Mumby, from the Global Change Institute and the ARC Centre of Excellence for Coral Reef Studies says the research complicates current understanding of marine reserve design, the findings can help make the best use of the limited resources available for coral reef conservation.

“Designing marine reserves for the long-term is more difficult than we thought”, Prof. Mumby says. “The responses of coral to the impacts of climate change are relatively unknown at this stage. Yet the good news is that some geographic locations were consistently selected in the generated scenarios, regardless of how corals might adapt to warmer temperatures.

“These areas are great contenders for early conservation no matter what the future holds”. Prof Mumby adds that, “The research found good locations for protecting corals and we are providing this information to conservation partners in the Bahamas to help them in their efforts to work with local communities and establish new reserves.”

Prof. Mumby says the response of coral to climate change is an ongoing focus for scientists and conservation advice will be updated regularly to reflect new research findings.

Prof. Mumby says the world’s oceans are becoming warmer due to the increasing concentration of atmospheric carbon dioxide produced by the burning of fossil fuels. A rise in sea temperature by as little as 1°C causes stress to corals and can lead to coral bleaching, where corals lose their internal symbiotic algae that help them grow, and may result in vast areas of dead coral.

Scientists expect that warming sea temperatures could cause coral to die in large numbers. The destruction of coral reef ecosystems will expose people in coastal areas of developing countries to flooding, coastal erosion and the loss of food and income from reef-based fisheries and tourism.

Ultramarathoners Reveal “Safe” Injuries

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Ultramarathoners-Reveal

Ultramarathoners-Reveal

For some reason, every year a few dozen runners dash from southern Italy all the way to the North Cape of Norway, in what’s called the TransEurope-FootRace. It takes about two months to cover the almost 2,800 miles, about 45 miles a day.

In the 2009 edition, 44 of the 66 participants allowed themselves to be examined medically throughout. The findings were presented November 29th at the annual meeting of the Radiological Society of North America in Chicago. And some of the discoveries may be of use to the less ambitious among us.

Muscle volume of the legs actually went down 7 percent because of the incredible energy consumption of the daily distances. And some leg injuries were found to be safe to run through. It was okay to keep going with simple leg muscle inflammation, for example. But other overuse injuries, like joint inflammation, carried a greater risk of worsening. Runners lost 40 percent of their body fat in the first half of the race and 50 percent altogether. Beginning runners can likewise expect to see a rapid fat loss at first. And you get to stop before reaching Norway.

Cybertherapy, placebos and the Dodo effect: Why psychotherapies never get better

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11-29-Sigmund-Freud

When the media report on a new diet that supposedly helps people lose weight once and for all, I wonder, “Does anyone still believe these claims, given the dismal track record of diets?” I have the same reaction to new treatments for psychological disorders, such as “cybertherapy.”

In a long, lavishly illustrated article in The New York Times, Benedict Carey reported that psychotherapists are harnessing virtual reality for treating social anxiety disorder, alcoholism, agoraphobia, gambling addiction, post-traumatic stress disorder and a host of other mental ailments. Therapists can, in effect, place an alcoholic in a bar, an acrophobe in a rooftop party and someone who fears public speaking in front of a large, restless audience. They then can manipulate the virtual environment to test patients’ ability to cope with different situations.

Patients can also discuss their troubles with a virtual therapist, relying on voice recognition and artificial intelligence software to parse remarks and respond appropriately. The therapist can take any form—male, female, black, white, young, old. The virtual therapist is a souped-up version of Eliza, an automated therapist that was created at the Massachusetts Institute of Technology in the 1960s and communicated via typed messages.

The U.S. Army is spending $4 million a year on research into cybertherapy for traumatized veterans, according to the Times. In a program developed at the University of Southern California, veterans roll through a virtual Iraqi village in a Humvee, which is attacked by bullets and bombs. The Army’s interest in cybertherapy evokes a certain cognitive dissonance because the military also employs virtual reality to prepare soldiers—from ground troops to pilots—for combat.

Cybertherapy sounds fascinating, and fun, but does it work? The Times story addresses this crucial question in its 31st paragraph. Researchers at the University of Quebec compared patients who received conventional talk therapy with others who got cybertherapy. “Both groups showed improvement, faring much better than a comparison group put on a waiting list,” the Times reported.

So cybertherapy is about as effective—or ineffective—as more conventional talk therapy. This finding confirms the so-called Dodo effect, which was originally proposed by the psychologist Saul Rosenzweig in the 1930s, when psychoanalysis was spawning a host of variants. He speculated that all talking cures share certain common factors—such as a caring therapist who establishes a bond with the patient—that make them equally helpful.

“Dodo” refers to an episode in Lewis Carroll’s fable Alice’s Adventures in Wonderland in which Alice and other characters wash up onto an island. There they encounter a Dodo bird who persuades them to race around the island. The Dodo finally announces that the race is over and proclaims, “Everyone has won, and all must have prizes!”

Over the last few decades, the psychologist Lester Luborsky of the University of Pennsylvania tested the Dodo effect by comparing different psychotherapies, including psychoanalysis, cognitive-behavioral therapy and interpersonal therapy. His research confirmed that all methods are equally helpful to patients. Claims that one therapy is more effective than others, Luborsky showed, can usually be explained by the “allegiance effect,” the tendency of researchers to find evidence for the therapy that they practice or favor.

Ironically, Luborsky, who died in 2009, displayed the allegiance effect himself. He strongly defended the value of psychotherapy in general and psychodynamic therapy in particular; psychodynamic therapy is a watered-down form of psychoanalysis that Luborsky favored in his clinical practice.

Other prominent researchers—notably Jerome Frank, a psychiatrist at Johns Hopkins—realized that the Dodo effect undermined the validity of all psychotherapies. Frank’s own research corroborated the Dodo effect. In one study, he and colleagues provided depressed patients with three treatments: weekly individual therapy, weekly group therapy and minimal individual therapy, which consisted of just one half-hour session every two weeks. “To our astonishment and chagrin, patients in all three conditions showed the same average relief of symptoms,” Frank wrote in Persuasion and Healing: A Comparative Study of Psychotherapy, first published in 1961 by Johns Hopkins Press and reissued in 1993.

Frank asserted that “relief of anxiety and depression in psychiatric outpatients by psychotherapy closely resembles the placebo response, suggesting that the same factors may be involved.” The specific theoretical framework within which therapists work has little or nothing to do with their ability to “heal” patients, Frank contended. The most important factor is the therapist’s ability to persuade patients that they will improve.

Frank’s view should disturb anyone who thinks psychotherapy has a scientific basis. It doesn’t matter whether your therapist is a Jungian, cognitive behaviorist, witch doctor—or a cybertherapist that exists only in a computer. What matters is whether you believe you will get better.

If talk therapy is really just a form of faith healing, should we abandon it and rely only on psychopharmacology for treating disorders such as depression and anxiety? Not necessarily. As Sharon Begley, one of my favorite science writers, pointed out in Newsweek in January, the placebo effect—and allegiance effect—may also account for the reported benefits of antidepressants. All are losers, and none must have prizes.

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