News this Week

Science  27 Sep 2013:
Vol. 341, Issue 6153, pp. 1434

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  1. Around the World

    1 - Berlin
    A Win for German Science?
    2 - Bethesda, Maryland
    NIH's Alzheimer's Gamble
    3 - Moscow
    RAS Merger Goes Forward


    A Win for German Science?

    Winning smile.

    German Chancellor Angela Merkel was reelected Sunday.


    German Chancellor Angela Merkel, who started her career as a quantum chemist, and her party, the center-right Christian Democrats (CDU), were the big winners in Sunday's elections, with 41.5% of the vote—far ahead of their main rivals, the Social Democrats (SPD), who received 25.7%.

    The victory presents Merkel with a quandary, however, because her favored coalition partner, the Free Democrats, failed to reach the 5% cutoff for representation in the German parliament. That means she has to form a coalition with one of two center-left parties, the SPD or the eco-oriented Greens. The negotiations are expected to take weeks.

    Germany's "Energiewende," an effort to transition away from nuclear and fossil fuels toward renewables, is likely to continue no matter what coalition forms. All the parties have ambitious carbon dioxide reduction goals in their platforms. Both CDU and SPD see efficient coal and gas as an acceptable bridge technology. The Green Party wants to block any new coal-fired plants.

    Many research leaders hope the new government will pass a constitutional amendment allowing the federal government to finance universities directly.

    Bethesda, Maryland

    NIH's Alzheimer's Gamble

    The National Institutes of Health (NIH) announced last week that it will give $33 million to yet another clinical trial of a drug that targets amyloid plaques—the hallmark protein tangles that clog brain cells in people with Alzheimer's disease.

    So far, such drugs have failed in clinical trials, but some scientists believe this is because they were administered too late, after brain damage is irreversible. Lead researchers Eric Reiman and Pierre Tariot of the Banner Alzheimer's Institute in Phoenix plan to give a yet-to-be-identified antiamyloid drug to 650 participants in their 60s and 70s who carry two copies of the APOE4 gene—a genetic double whammy that confers a 10-fold increased risk of developing Alzheimer's late in life. Roughly a third will likely not have much amyloid in their brains yet, allowing the researchers to track whether the drug affects its accumulation, Reiman says.

    Given that no anti-amyloid drugs have yet shown clinical efficacy, the agency is "taking a gamble" by using the lion's share of its Alzheimer's research budget for the study, says Gary Landreth, a neurologist who studies the disease at Case Western Reserve University in Cleveland, Ohio.



    The Russian Academy of Sciences will be merged with two other academies.


    RAS Merger Goes Forward

    In June, when Russian legislators agreed to delay finalizing a bill that would strip the Russian Academy of Sciences (RAS) of control of its budget and real estate holdings and merge it with two other academies, scientists saw a chance to press their case for keeping the august body intact (Science, 12 July, p. 114). But more than 2 months of lobbying and protests were in vain: Russia's lower house of parliament has approved a measure that will radically transform the 289-year-old academy.

    Under the bill, expected to be approved by parliament's upper house and then signed into law by President Vladimir Putin this week, a new Agency for RAS Scientific Institutions, directed by the academy's president, Vladimir Fortov, will manage the budget and assets of the merged academies. Researchers worry that Fortov will be only a figurehead and that officials inimical to RAS will pull the strings. "It's like being a member of an orchestra whose conductor is not a musician but a bureaucrat," fumes Vladimir Zakharov, a physicist at RAS's P. N. Lebedev Physical Institute in Moscow.

  2. Newsmakers

    Smithsonian Secretary to Step Down



    G. Wayne Clough, 72, announced last week that he will step down as head of the U.S. Smithsonian Institution in October 2014. Clough, who started as secretary in July 2008, says his focus from the start was on "restoring the vitality and forward-looking ethic" of the organization; concerned about the Smithsonian's reputation as "the nation's attic," which suggested that most of its 137 million specimens and objects were hidden away gathering dust, he conducted vigorous outreach to the U.S. Congress, potential donors, and the public, and used the Internet to expand access to collections and interactive programs. Clough also laid the groundwork for the Smithsonian's first national capital campaign, which has already netted $893 million in private contributions since 2008.

    Clough came to the Smithsonian promising to stay 5 years, but didn't want to commit to another five. "You can't do [this job] at 80 or 90%, you have to do it at 110%." He insists that he's not retiring, but plans to spend more time with family and on book projects. The Board of Regents that oversees the Smithsonian says it will be launching an international search for Clough's successor.

  3. Random Sample

    Lucy Gets a New Look


    The 3.2-million-year-old hominin Lucy has had a makeover, thanks to newly discovered fossils. The reconstruction displays a trimmer figure with a distinct neck, a narrower waistline, and arched foot. Earlier reconstructions, relying on scanty fossil rib bones and living African apes such as chimpanzees and gorillas, gave her a cone-shaped thorax and potbelly, implying that her species, Australopithecus afarensis, had retained adaptations for moving in the trees like chimps. But in the past few years, researchers have found curved A. afarensis ribs, which translates to a barrel-shaped thorax like modern humans, and an arched foot bone, which suggests that Lucy and her kin spent plenty of time on the ground, although they probably still climbed and slept in trees. The reconstruction, overseen by paleoanthropologist Yohannes Haile-Selassie of the Cleveland Museum of Natural History and created by artist John Gurche, was unveiled on 20 September at Ohio's Cleveland Museum of Natural History.


    NASA's Deep Impact mission was officially declared dead last week, after more than 8 years in space, 7.6 billion kilometers traveled, and a close-up view of two comets—slamming an impactor into one and flying by a second during the probe's long, successful life. Its last signal was received on 8 August; NASA declared the mission over last week.

    They Said It

    "Cynically, this feels like a ploy to boost Google's mystique. Optimistically, it feels like another one of Google's fickle interests."

    —Caleb Garling of the San Francisco Chronicle, commenting last week on Google's creation of Calico, a biotech firm with vague plans to address aging and its associated diseases.

    By the Numbers

    33% Reduction in the annual number of new HIV infections worldwide from 2001 to 2012, according to a UNAIDS update released on 23 September.

    $1.4 trillion Economic rewards of the estimated 2.3 billion tons of world crops that could be grown with better land management, according to a U.N.-backed report published on 24 September by the Economics of Land Degradation Initiative.

    $500 million Amount Oregon Health & Science University officials have pledged to raise for cancer research in the next 2 years, to receive a matching donation from philanthropists Phil and Penny Knight.

    String Theory Goes Viral

    Oh mamma mia mamma mia.

    "Such a sea of particles! A tachyon, with a dilaton and gravity."


    "Is string theory right? Is it just fantasy?" sings Tim Blais in "Bohemian Gravity," the a cappella song parody that has garnered more than 1 million hits on YouTube, earned a plethora of blog mentions, and won the 23-year-old musician his 15 minutes of online fame. A take on the 1975 Queen rock aria, Blais's creation features complex musical arrangements and video that he edited over the last year while he worked to complete a master's degree in physics at McGill University in Montreal.

    A singer, piano player, and composer, Blais wrote his first science-themed YouTube foray, "Rolling in the Higgs"—inspired by the soulful song by Adele—during the live-streamed announcement of the Higgs boson discovery last year. Having received his degree, Blais says he was looking forward to leaving science for a while to focus on his first love: performing music. "But now, because of the video, people are encouraging me to do a lot more science-based music," he says.

    What do prominent critics of string theory think? "A fabulous bit of '80s nostalgia," was how Lee Smolin of the Waterloo, Canada–based Perimeter Institute put it. "I'm not in the mood to analyze the scientific arguments," said Peter Woit of Columbia University, but he calls the video "fantastically good."

    The recognition most meaningful to Blais? Mention by Queen guitarist Brian May, an astrophysicist who is now chancellor emeritus at Liverpool John Moores University in the United Kingdom. "Is that ME at the top of Brian May's website? I think I just won at life," Blais wrote on Facebook.


    Join us on Thursday, 3 October, at 3 p.m. EDT for a live chat on "Rocknest" and the latest findings from the Mars Curiosity rover.

  4. Mercury Pollution

    Taming a Mercurial Element

    1. David Malakoff

    Can a landmark global agreement to curb mercury pollution make a difference?

    Beautiful killer.

    Mercury, here on a gold miner's thumb, can cause brain damage and birth defects.


    At room temperature, mercury can puddle in your palm like some silver elixir. Ancient alchemists believed the glittering metal was the origin of all matter; healers saw it as the key to eternal life.

    In fact, however, mercury is a potent toxin that causes cell death, brain damage, and birth defects. Unfortunately, it is also a widespread byproduct of common industrial processes, such as burning coal, and is widely used in trades such as gold mining. Humans have released some 200,000 metric tons of mercury into the environment since 1850, researchers estimate, with sometimes staggering costs to human health.

    On 9 October, representatives from more than 140 nations will gather in Japan to officially embrace a global agreement aimed at reducing mercury's threat—and spurring the research needed to do so (see story, p. 1443). Fittingly, the delegates are gathering in Minamata, a seaside town that was devastated by mercury pollution a half-century ago and is still struggling with that legacy (see story, p.1446). The new convention seeks to prevent similar disasters elsewhere, such as in the world's rapidly expanding artisanal gold mines, which are now the planet's leading source of new mercury pollution (see story, p. 1448).

    Mercury's, well, mercurial properties make it hard to get a grip on. But the world is now going to try.

  5. Mercury Pollution

    With Pact's Completion, the Real Work Begins

    1. Naomi Lubick,
    2. David Malakoff

    The Minamata Convention on Mercury seeks to curb or end most uses of mercury. It also calls for plenty of research.

    Peaks and valleys.

    Studies suggest mercury emissions surged before and after the chaos of World War II and the Great Depression.

    CREDIT: D. G. STREETS ET AL. ENVIRON. SCI. TECHNOL. 2011, 45, 10485–10491

    STOCKHOLM—An elegant crematorium sits in a wooded cemetery here on the edge of the city. It once reduced corpses to ash. But government regulators shut it down not long ago, because its old-fashioned ovens couldn't prevent toxic mercury in the dental fillings of the dead from wafting into the atmosphere, and ultimately falling back to Earth and threatening the living.

    Thousands of similar crematoria, and countless other industrial sources of mercury, could eventually face similar regulation as a result of the Minamata Convention on Mercury to be finalized in Japan next month. Years in the making, the agreement calls on signing nations to launch a wide range of initiatives to reduce mercury pollution, which can cause birth defects, brain damage, and disease in humans and other animals. Goals include curbing mercury emissions from coal-fired power plants and industrial facilities, phasing out by 2020 many consumer products that contain mercury, "phasing down" the use of mercury in dental amalgams, and closing all mercury mines within 15 years after the convention takes effect. (Use of existing mercury in research and medicine, however, could continue.)

    Making tracks.

    Mercury emissions can move vast distances around the planet in air and water, settling for centuries before being re-emitted to the environment in new forms.


    It's an ambitious to-do list, and many of the convention's goals are essentially voluntary, qualified with the phrase "where feasible." But modeling studies suggest that it could, under aggressive regulatory scenarios, help reduce global mercury emissions by 15% to 35% in coming decades.

    Still, even some who welcome the convention worry it doesn't go far enough, fast enough. Negotiators stopped short, for instance, of requiring many industrial and power plants to rapidly curb their mercury emissions, giving some a decade or more to act. "That's a lot of mercury" that will be added to the environment in the meantime, says Susan Egan Keane, an environmental analyst at the Natural Resources Defense Council in Washington, D.C. But "the reality is that we wouldn't have had a treaty at all if we didn't have those compromises."

    The pact also includes plenty of work for researchers. It tasks nations with beefing up efforts to monitor and tally mercury releases from a slew of sources (see bottom graphic, p. 1445). It also calls for improving efforts to understand mercury's complex chemistry, and how the toxin moves through food chains and ecosystems. And it includes landmark language emphasizing the importance of protecting human health and developing science-based methods of monitoring people at risk of exposure. Such data will be essential to determining whether the convention is achieving its goals—and to enforcing any new mercury controls.

    "Under no circumstances do I think this treaty is a silver bullet," says Henrik Selin, a policy researcher at Boston University. But it will become "a focal point" for science and innovation, he predicts.

    Trust but verify?

    Shifting shares.

    Artisanal gold mining has become the world's leading source of mercury emissions in recent years.


    One major task will be clarifying how mercury enters and moves through the environment (see top graphic, p. 1445). Today, researchers estimate that human actions annually dump some 2000 metric tons of the heavy metal into air and water. That's down from an estimated peak of some 2600 metric tons per year in 1890, during a gold and silver mining boom in North America (see graph).

    But there's plenty of uncertainty in those numbers: The United Nations Environment Programme (UNEP), for instance, recently estimated that annual air emissions could total as little as 1010 metric tons or as much as 4070. Even less certain are the amounts released into water, and the quantities "re-released" into the environment by the vast stores of mercury that have piled up in soils and sediments over the past few centuries. Overall, studies suggest that these "re-emissions" account for about 60% of annual air emissions, double the share contributed by current sources. (Natural sources such as volcanoes and forest fires account for 10%.)

    Firming up such figures is a key goal of the new convention, which calls on signers to submit detailed—and accurate—emissions reports. Some existing data gaps might be filled simply by improving tracking of mercury purchases or requiring industries to file more detailed pollution reports. But assembling truly solid data could also require upgrading the world's existing patchwork of permanent monitoring stations, which feature sensitive instruments able to detect specific mercury compounds. "We have to be able to verify [a country's] emissions inventory … by cross-checking with monitoring and real data," says Nicola Pirrone, director of the Institute of Atmospheric Pollution Research in Rome.

    Creating an effective global monitoring system could be a tall task. Although the United States, Canada, and Europe have run relatively robust mercury measurement programs for more than a decade, other regions, especially in the Southern Hemisphere, are barely covered. In one nascent effort to change that, in 2010 Pirrone won support from the European Union to launch a Global Mercury Observation System. In cooperation with others, it has begun installing instruments in places such as Brazil and Argentina. But its future is unclear; the European Union promised just 5 years of funding, and the new instruments are expensive, costing tens of thousands of dollars to build and operate. And although the Minamata Convention calls on wealthier nations to help poorer ones boost their data-gathering capabilities, so far there is no concrete funding plan.

    Studies have also suggested that some commonly used instruments may not be able to detect important varieties of mercury that form in the atmosphere, giving a misleading picture of emissions and their final resting place. Such findings are a reminder that much of mercury chemistry is still a mystery; scientists don't understand key oxidation processes in the atmosphere, for instance, or how the metal moves and behaves at high altitudes. "If we don't know [such atmospheric chemistry], we don't know anything," says Dan Jaffe, an atmospheric chemist at the University of Washington, Seattle.

    Healthy accord

    Although the agreement doesn't spell out exactly how its human health provisions should be implemented—or how the work would be paid for—past agreements could provide a guide. Under the 2001 Stockholm Convention on Persistent Organic Pollutants, for instance, nations ultimately agreed to create coordinated databases that record levels of pesticides and other chemicals in breast milk in order to track infant exposures. Signers of the Minamata Convention could choose to pursue that kind of biomonitoring and reporting infrastructure for mercury, too.

    Countries still need to work out what kinds of data to collect, however. Although blood samples can provide extensive information on total mercury exposure, for instance, they can be intrusive to collect and costly to maintain. An alternative might be gathering hair or urine samples, but recent research has shown that each might accumulate a different record of mercury exposure, potentially skewing results. There is also the question of which populations should get priority for biomonitoring—and how to make sure they derive some benefit from research.

    Such issues are likely to come to the fore as nations begin to implement the Minamata Convention, which will enter into force once 50 nations have ratified it. Then, the clock starts ticking: Nations are supposed to meet for an initial "effectiveness evaluation" within 6 years. By then, researchers hope to be able to report on whether efforts to limit mercury pollution are on track, or are still falling short.

  6. Mercury Pollution

    In Minamata, Mercury Still Divides

    1. Dennis Normile

    Nearly 60 years after a chemical plant caused one of the world's worst episodes of mercury poisoning, the Japanese town that came to symbolize the metal's threat is still struggling with the aftermath.

    Toxic legacy.

    Decades after mercury pollution ended in the town of Minamata, victims still need help.


    MINAMATA, JAPAN—Anyone arriving here by train gets the message that this is a company town: The station doors open to a broad tree-lined street that leads directly to the gates of what was once the Shin Nippon Chisso Hiryo chemical plant. The street bisects downtown, mirroring a deeper division in the community that has given its name to the Minamata Convention on Mercury.

    Nearly 6 decades after researchers identified the first victims of what came to be called Minamata disease, and 45 years after the government officially recognized that methylmercury discharged from the Chisso plant had caused one of the most notorious pollution disasters of all time, this community and scientists are still split over the calamity, and in some very curious ways. The town hosts both official and "unofficial" Minamata disease museums, for instance. There are also twin disease research institutes, one sponsored by the government, the other by a university.

    The two blocks are not—on the surface—antagonistic. "We may have different perspectives, but that doesn't mean we are enemies," says Kunio Endo, a director of the Minamata Disease Center, a citizens' group which operates the unofficial Minamata Disease Museum. But the differences in style and emphasis are clear. The unofficial museum is housed in a tin-roofed shed that sits along a narrow lane high above the town. On a hot, humid day, breezes through open doors provide only occasional relief.

    In contrast, the official Minamata Disease Municipal Museum overlooks the bay in a sleek, modern building that is comfortably airconditioned. And while the municipal museum's slick displays tend to reflect the official line that the Minamata incident is largely resolved, its unofficial counterpart stresses patients' and advocates' view that the tragedy is still unfolding. "There are still many unresolved issues," says Masanori Hanada, a social policy specialist who heads the Open Research Center for Minamata Studies, attached to Kumamoto Gakuen University.

    Among them: finding ways to identify patients with less severe mercury poisoning symptoms, and figuring out how low-level or early-life exposure is affecting people as they age. There are also fierce, ongoing battles over who should be counted among the victims of Minamata disease, who could number just a few thousand or up to 100,000—depending on who is counting.

    A historic divide

    Ground zero.

    Minamata disease was ultimately linked to a chemical plant in the community.


    The split in the Minamata community existed even before the disease emerged. The company that ultimately became Chisso Corp. opened a fertilizer plant in the town in 1908 and gradually diversified into a range of chemicals. In 1932, Chisso began making acetaldehyde, used to produce a range of synthetic materials. The production process relied on mercury sulfate as a catalyst, producing an unwanted byproduct known as methylmercury—a potent form of mercury now known to enter the food chain and accumulate in fish and other animals and cause brain damage and birth defects.

    As Chisso prospered, Minamata grew, and its economy bifurcated. By the 1950s, roughly one-half of the town's residents depended directly or indirectly on the company for their livelihood. The other half stuck with their traditional livelihoods: fishing and farming. In the spring and summer of 1956, what was first known simply as "a strange disease" started afflicting fishing families in villages scattered around Minamata Bay. Symptoms included numb hands and feet and difficulty walking and talking. Severe cases progressed to convulsions and death. Of 54 patients identified in 1956, 17 died that year, according to the National Institute for Minamata Disease, the "establishment" research institute.

    By year's end, Kumamoto University researchers believed the cause was eating local fish and shellfish contaminated with heavy metals. Suspicion focused on the Chisso plant, which discharged its untreated waste directly into waterways. But for several years, Chisso refused to disclose any information; investigators later found that executives covered up in-house research suggesting a link between its wastewater and the illness, and put forward alternative theories.

    Residents were divided, either blaming or defending the company. Victims and their families were ostracized; at first, many townspeople feared the illness might be contagious.

    In 1959, under pressure from the fishing industry and the national government, Chisso installed a wastewater treatment system. It was of little use, according to a 2011 report prepared by Japan's Ministry of the Environment. "It was later discovered," the report noted, "that the system was not designed to remove mercury and was useless for the removal of methylmercury." In December 1959, Chisso agreed to compensate known victims and fishers, although the company continued to push alternative theories for what was causing the illness, by then dubbed Minamata disease.

    For the next 9 years, Chisso and national and local governments considered the case closed. Officials were concerned about the economic impacts of closing or reengineering the plant. So the wastewater taps remained open, and methylmercury continued to accumulate in the tissues of fish and shellfish. The metal also continued concentrating in those who ate seafood, including in the placentas of expectant mothers, exposing the unborn babies to a potent neurotoxin.

    Finally, in May 1968, Chisso halted acetaldehyde production, thus ending its use of mercury. (The plant still makes other products.) Later that year, the national government officially acknowledged that Minamata disease was caused by eating seafood contaminated by effluent from the factory. But the statements claimed the outbreak had ended in 1960. And through the early 1970s, the national government continued to play down the threat of eating contaminated seafood from Minamata Bay, ignoring the persistence of mercury in seafloor sediment. Government officials didn't close the bay to fishing until 1975 (lifting the ban in 1997 after massive dredging). Meanwhile, activists started drawing global attention to the growing human toll with dramatic photographs of disfigured, paralyzed victims. "If the national government had taken any measures to stop people from eating fish, we would have had many fewer patients," Endo says.

    Who is a patient?

    Exactly who those patients are is the subject of much medical and legal dispute, fed by uncertainty about exposure levels and symptoms. The year Chisso stopped using mercury, Minamata patients and advocates formed the Citizens' Council for Minamata Disease Countermeasures to support victims seeking compensation. Since then, there have been 45 years of negotiations, arbitrations, court judgments, bureaucratic diktats, and Cabinet decisions, as well as two laws enacted by the national legislature. The result: a bewildering patchwork of differing classes of victims, levels of compensation, and medical support.

    There are, for instance, some 2260 "Certified Minamata Disease Patients" selected by expert panels using strict criteria set by the environment agency in 1977. To qualify, a person must have more than one "severe" symptom, have lived in the most contaminated areas, and been born before 1969. Each has received a lump-sum payment ranging from $160,000 to $180,000 plus pensions and medical care.

    Under a 1995 national law, another 11,000 patients with less severe abnormalities became eligible for payments of $26,000 and support for medical expenses. And in 2009, the national legislature created yet another program to support those with even less severe disabilities.

    Last April, however, two Supreme Court decisions threw the system into turmoil, overruling one of the expert panels that certifies victims and questioning whether it was scientifically justifiable to require patients to exhibit multiple severe symptoms to qualify. Meanwhile, 65,000 people have applied for compensation under the 2009 law.

    Endo says he believes the total number of people afflicted with Minamata disease could be as high as 100,000. One part of the challenge, critics of the current system say, is that screening for signs of methylmercury poisoning was done several years after the crisis and in a piecemeal way. Another is that even people who were exposed to biologically harmful levels may not be aware they have symptoms. "I cannot distinguish by feel whether I'm touching someone's hair or their shirt," says Hajime Sugimoto, a 52-year-old, third-generation Minamata fisherman who lived in Tokyo and worked odd jobs during the ban on fishing. He says he also cannot tell when he has his hands in cold water. But when he was a child, "I thought this was just normal."

    To help identify other such "quiet" victims, a team led by Shigeru Takaoka, a physician at the private Kyoritsu Neurology and Rehabilitation Clinic in Minamata, has been doing its own surveys. At the International Conference on Mercury as a Global Pollutant in Edinburgh in July, they reported finding extensive signs of methylmercury poisoning in more than 1000 people living on the coast of the Shiranui Sea, which contains Minamata Bay. "These people are not like the victims seen in the [famous] photographs, but they are Minamata disease patients," Takaoka says.

    The long view

    More patients could emerge as Minamata's population ages, Takaoka says. His surveys suggest that symptoms may appear or worsen as those exposed get older, but so far there are no large-scale, systematic studies.

    The slow, late, and cumbersome process of identifying Minamata patients is somewhat ironic, critics note, given that the new convention includes unusual language that commits signers to efforts to understand and monitor the health threats posed by mercury (see story, p. 1443). But it may be in keeping with the conflicted views that many Minamata residents have of the horrendous event that gave the town global recognition. Although the Japanese government successfully lobbied hard to get the convention named for Minamata, Endo says that 90% of residents "are not happy about an incurable disease being named after their hometown."

  7. Mercury Pollution

    Gold's Dark Side

    1. Lizzie Wade

    Small-scale artisanal gold mining has become the world's leading source of mercury pollution, poisoning air, rivers, and people.


    Artisanal miners use mercury to trap flecks of gold, then burn off the toxic metal.


    People come to La Rinconada, Peru, for one major reason: gold. There's little comfort, and not much oxygen, to be had in the world's highest city, which climbs windswept slopes at an altitude of more than 5000 meters. But the surrounding Andes mountains are full of the precious metal, and more than 35,000 people have flocked there to mine it, trade it, or otherwise strike it rich.

    But if there's gold in the hills, there's a far more sinister element lurking in the city's air, water, and food: mercury.

    Endowed with a unique ability to extract gold from low-grade ore, mercury remains the method of choice for artisanal gold miners working near La Rinconada and elsewhere in Latin America, Asia, and Africa. Often very poor, these miners work alone or in small groups, using mercury to separate and bind flecks of gold from soupy slurries of water and sediment. They are outlaws in many countries, eking out a living on the margins of the formal economy. And yet this diffuse industry is now the world's largest mercury polluter, pumping more mercury into the environment than all the world's coal-fired power plants combined. The mining operations typically leave a trail of mercury waste, putting as many as 100 million people at risk of poisoning.

    "If you're going to do something about mercury pollution, you have to do something about small-scale mining," says Susan Egan Keane, a senior environmental analyst at the Natural Resources Defense Council (NRDC) in Washington, D.C. She helped governments craft language in the Minamata Convention on Mercury that commits signers to reducing or eliminating mercury use in artisanal mining.

    High risk.

    An artisanal miner in Peru mixes mercury into a barrel of ore and water.


    Achieving that goal will not be easy, with gold prices soaring and as many as 15 million miners using an estimated 1600 metric tons of the metal in 2012 alone. Weaning them off mercury will require a blend of economic incentives and practical new technologies, and it could be years before a majority of miners are convinced to adopt them.

    It is "an extremely daunting problem," says Luis Fernandez, an ecologist and expert in artisanal gold mining at the Carnegie Institution for Science in Stanford, California. And the stakes are high: "Once areas are contaminated, they are contaminated for a long time."

    Why mercury?

    Add a palmful of mercury to a slurry of ore and "it serves almost like a sponge," Fernandez says. It soaks up gold that's too diffuse to pan, forming a heavy ball of puttylike amalgam that's easy to pluck out (see graphic, p. 1449). Miners and traders then burn off the mercury, often in an open flame, leaving just the gold.

    The process creates ample opportunity for pollution—and exposure. Miners simply dump the mercury-infused slurry, which contaminates rivers. Bacteria in the sediments help transform the inorganic mercury to organic methylmercury, which can be absorbed by phytoplankton and accumulate in fish and other creatures higher on the food chain. People who eat contaminated fish are at risk of neurological damage, autoimmune disease, and devastating birth defects. In a new study, Fernandez found that people in the Peruvian state of Madre de Dios, home to much of the country's artisanal gold mining, have mercury levels in hair averaging 3 parts per million, triple the maximum limit recommended by the U.S. Environmental Protection Agency. "For the most part, these are people who are not miners. These are people who eat fish," Fernandez says. Levels are even higher—more than 5 ppm—in the state's indigenous communities, which rely on local fish for protein.

    In mining towns like La Rinconada, the threat is more direct: People are exposed every time they take a breath. As gold shops in the center of town burn the mercury-gold amalgams, mercury vapor wafts into crowded neighborhoods. "In effect, some of these little towns have the equivalent of four, five, 10, 20, coal-fired power plants in the center of them," Fernandez says. Meanwhile, mercury lifted into the upper atmosphere can travel vast distances before falling back to Earth and making its way into the global food web.

    Data dearth


    Documenting exactly how much mercury miners are using—and exactly how it is affecting people—has been a challenge. Artisanal gold mining often takes place in remote areas, and miners can be wary of scientists, whose findings could threaten their livelihoods. "We've been chased out of towns when we've tried to do surveys or a give a talk," Fernandez says. Still, researchers are making progress. The United Nations more than doubled its estimate of mercury emissions from artisanal mining between 2008 and 2013, "mostly due to better reporting," says Kevin Telmer, executive director of the Artisanal Gold Council in Victoria, Canada, which works to reduce mercury use in small-scale mining.

    The United Nations may not have the whole picture, however. "The more you look, the more you find," says NRDC's Keane. A 2011 study of the air quality in and around La Rinconada's some 250 gold shops, for instance, concluded that they could be emitting 20 metric tons of mercury per year. That's nearly one-third of Peru's reported annual emissions, suggesting that the official tally is a severe underestimate.

    Information on the health effects of artisanal mining is also scarce, because of the challenge of doing long-term studies in poor, remote, and sometimes hostile communities. When Daniel Peplow, an environmental toxicologist at the University of Washington, Seattle, was working with at-risk indigenous communities in Suriname, he recalls that community leaders said: "We're really tired of you people, you scientists, coming here, studying us, taking away information, and not coming back. We're not benefiting from your research." In response, Peplow founded the Suriname Indigenous Health Fund, which helps indigenous communities direct their own research on mercury's impact. Often, he says, they request screening programs to determine who has been exposed, as well as long-term monitoring to reveal whether efforts to reduce mercury exposure are improving health.

    Many observers, however, say the world already knows enough to take action. "There's ample information already available that shows that the people in small-scale mining communities are exposed to mercury, which is a well-characterized neurotoxin," Keane argues. The real issue is finding workable ways of getting mercury out of the global gold trade.

    Simply banning artisanal mining—or mercury—isn't a realistic option, specialists have concluded. "Making [artisanal mining] illegal hasn't worked," Keane says. It only demonizes miners and drives their activity further underground, cutting off the very resources they need to improve their practices: education, training, and credit. "You cannot deal with someone who officially doesn't exist," says Jacopo Seccatore, a doctoral student in mining engineering at the University of São Paulo in Brazil.

    The only winning strategy, Seccatore says, is creating economic incentives to reduce mercury use. "It's all a matter of efficiency. If [miners] get more gold from their ore than they do right now, they will shift immediately to mercury-free technologies." Indeed, mercury amalgamation often "wastes" more gold than alternative methods, some of which are as simple as running slurry through a box lined with a hairy piece of gold-trapping carpet.

    The problem, Seccatore says, is that switching to new techniques requires upfront resources that most miners don't have. "They don't have the structure, they don't have the knowledge, and they don't have the money to give up mercury for some safer technology." Plugging those gaps will require transforming artisanal mining into a more formalized industry, argues Marcello Veiga, Seccatore's mentor and a mining engineer at the University of British Columbia in Vancouver, Canada. To that end, Veiga and Seccatore are working with the Ecuadorian government to establish the International Training Centre for Artisanal Miners (ITCAM) in Portovelo. By training miners to use environmentally sound techniques and attract investors with business plans, they hope to "turn every artisanal miner into a responsible, small-scale miner," Seccatore says.

    Such economic strategies ring true with the gold council's Telmer. "Health [and] environmental messages will fall on deaf ears and have for 30 years," he says. And Latin America is an attractive place to try experiments like ITCAM, he adds, because many of the region's miners are already organized into cooperatives, unlike in Africa and parts of Asia, where miners usually work alone.

    The Minamata Convention could also help create economic incentives for change. It calls for ending the primary mining of mercury within 15 years once 50 nations have ratified it, ultimately limiting supplies and likely raising prices. "Inevitably there will be a squeeze on mercury," Telmer predicts. That could help make alternative techniques more attractive to miners, and even encourage gold shops to capture, recycle, and resell mercury they now burn.

    Still, specialists fear that the convention may be too little, too late to erase gold's toxic legacy. Ultimately, the agreement may "do a great job stemming the flow of mercury" from artisanal mining and other sources, Peplow says. But the vast quantities of mercury already dumped by artisanal mining will persist in ecosystems for hundreds of years, he notes, and "there's no going back."