correlates well with levels of phosphorous, a nutrient that causes eutrophication and may threaten species in decline, such as the world’s largest freshwater salmon, the Hucho taimen or “tiger of the river”. “It’s really crazy to go in and rip up a stream. I think we as a society are beyond that now,” says Glenn C. Miller, director of the graduate program in environmental sciences and health at the University of Nevada. Miller is an expert on mines in the western United States and spent last summer examining mining activity on the Russian side of the Selenga watershed. “It’s not even the Mongolians that that are doing it,” he adds. “It’s these outside organizations that have the technology.” With a GDP of only $5 billion (slightly greater than the budget of Orlando, Fla.), the Mongolian government has made the country a very attractive place for international mining conglomerates, which partner with local Mongolian companies. The corporations are taxed a percentage of their earnings, and because larger companies are taxed at higher rates, large conglomerates typically break up into smaller subsidiaries to maximize profits. Indus-
try sources state that mining is now Mongolia’s largest industry, accounting for more than 55% of its industrial output and 40% of its export earnings. “It’s kinda’ laughable,” Stubblefield says. “We toured one of the dredges, and a worker pointed to a tiny postage stamp for remediation. It was literally 30 square meters, and surrounding it were kilometers of gravel piles.” Although Mongolia does not allow companies to employ mercury for gold extraction, its own government officials admit that some companies use mercury illegally. And scientists attribute mercury use to locals nicknamed “ninja miners”, villagers who sneak into the gravel ponds at night and pan for gold. Scientists worry about the longterm environmental problems Mongolia will experience when mining ceases. They cite California as an example: More than 100 years after the California gold rush, the state still spends millions of dollars annually to clean up mines. “Mongolia is so hungry to get any kind of industry in to help pay the bills,” says Miller. “And they’re not too selective about the people who go in.” —PAUL D. THACKER
“Dead zones” on the rise The number of oxygen-starved “dead zones” in coastal waters has doubled over the past decade to nearly 150 worldwide and is projected to become the greatest threat to marine ecosystems, according to a new report from the UN Environment Program (UNEP). The culprit is the 160 million tons of nitrogen dumped into the environment every year from fertilizers, sewage, and fossil-fuel burning, which are driving the growth of massive algal blooms that die and then consume oxygen. The nitrogen inputs must be scaled back through efficient fer-
tilizer use, appropriate sanitation technologies, and scrubbing nitrogen from exhaust gases, UNEP says. The report, released on March 31 as the first annual Global Environment Outlook Year Book 2003, highlights the fertilization of the planet as a spreading threat due to a rapidly growing and industrializing human population, says Nick Nuttall, a spokesperson for UNEP. “Oxygen-starved coastal waters will worsen as developing countries expand the use of industrial fertilizers and increasing human numbers put cities on a massive growth
News Briefs Ecologists take Stockholm Prize Two ecologists will share the 2004 Stockholm Water Prize for their pioneering work in the modeling and understanding of how lakes and wetlands function. The Stockholm International Water Institute, a policy think tank dedicated to addressing the world’s water crisis, announced its decision in March. Sven Erik Jørgensen, 69, professor of environmental chemistry at the Danish University of Pharmaceutical Sciences in Copenhagen, and William Mitch, 56, professor of natural resources and environmental science and director of the Olentangy River Wetland Research Park at the Ohio State University in Columbus, will share the $150,000 award for contributing substantial work to understanding welands. Since 1990, the prize has been awarded for outstanding achievements in water science, management, or awareness. For more information, go to www.siwi.org.
Nuclear power to fill gap Canada’s Ontario province should invest in nuclear power, according to a new report from the Ontario Ministry of Energy. To meet an international commitment to cut ozone levels by 2007, Ontario plans to close its five coal-fired plants, which currently provide more than 20% of the province’s electricity supply. The report recommends a plan for Ontario Power Generation, Ontario’s publicly owned electricity utility. The first step of the $600 million plan is to restart one of three mothballed reactors at the Pickering A Power Station, which could generate 3.8 billion kilowatt-hours of electricity per year for 12 years. For more information on Transforming Ontario’s Power Generation Company, visit www.opgreview.org/eng.
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Environmental▼News curve, generating more sewage and exhaust gases,” he warns. The nutrient overload, which has nearly tripled the amount of nitrogen delivered to vulnerable coastal seabeds through natural processes, generates low oxygen zones that range in size up to 70,000 km2, the report says. Fisheries are destroyed when oxygen concentrations drop below 2 milliliters of oxygen per liter because adult fish suffocate and their spawning habitat is ruined, says Bob Diaz, a marine biologist at the College of William and Mary and a coauthor of the report. “In the 20th century, loss of fish stocks from over-fishing was the biggest marine issue, but in the 21st century the key factor affecting fish stocks will be oxygen depletion,” he says. Since the 1960s, the number of
oxygen-depleted ecosystems worldwide has doubled every 10 years to a total of 146, the report says. Climate change could compound the problem in areas where increased rainfall flushes more nutrients into coastal waters and strengthens the stratification of the water column, which cuts off fresh oxygen inputs to bottom waters. For example, the report predicts that a doubling of carbon dioxide levels would boost Mississippi River discharge into the Gulf of Mexico by 20%, leading to a 50% increase in algal production, a 30–60% decrease in oxygen, and expansion of the Gulf’s dead zone. Precision agriculture, matching fertilizer applications to plant needs, and removing nitrogen from exhaust gases of power plants and cars are part of the solution, Nuttall says.
Sustainable sanitation, composting toilets, and biological sewage treatment systems are a must, especially in light of the UN’s goal to halve the number of people without hygienic sanitation by 2015, he adds. Nutrient loads have dropped in some watersheds, revealing long lag times prior to recovery, says Don Boesch, oceanographer at the University of Maryland’s Center for Environmental Science. For instance, after the collapse of the Soviet Union, farmers couldn’t afford fertilizers, and nitrogen concentrations at the mouth of the Danube River dropped by half. In 1996, five years after inputs were cut, the dead zone in the Black Sea did not recur for the first time since the 1970s, he says. The report is at www.unep.org/ geo/yearbook. —JANET PELLEY
Simple method advances degradation studies taining particles stuck, although he had to test several resins before he found one strong enough that didn’t “creep” over the entire particle. However, even the most viscous resin would overwhelm very small particles like iron oxide. So Birkefeld also devised a way to adsorb ANDREAS BIRKEFELD
A new method for monitoring how particulate pollutants degrade in soil requires only Plexiglas, commercially available resin, and some string. Tests show the method is simple but effective. Soil scientists investigating the risk posed by pollutants such as heavy-metal-containing dusts or residues from mines have lacked a good method for studying how the particulates break down in soils. Researchers had tried burying mesh bags filled with minerals in the ground, but too many variables prevented quantitative results. Andreas Birkefeld, a doctoral candidate at the Swiss Federal Institute of Technology (ETH) in Zurich, and his advisors, Bernd Nowack and Rainer Schulin, decided to find a better approach. “We wanted the particles in direct contact with the environment to avoid any interference,” said Birkefeld, after he presented the results at the ACS national meeting held in Anaheim, Calif., in late March. To do that, he coated 2-centimeter polymethylmethacrylate polymer supports—more commonly known as Plexiglas—with a thin coat of epoxy resin. The metal-con-
A lead oxide particle fixed with epoxy resin to a Plexiglas support degraded over time in soil. Birkefeld used scanning electron microscopy images to examine the particle’s surface and analytical techniques to quantify the amount of metal lost.
such tiny pollutant particles to larger quartz surrogates before attaching them. The particles on the plates are easily analyzed for degradation and development of new mineral phases using standard methods such as X-ray fluores-
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cence, scanning electron microscopy, and Raman spectroscopy. Birkefeld tested the approach by burying the plates in an open field test site near ETH that had been previously well characterized. Over the past year and a half, he dug up two plates from the soil every other month for analysis. In these experiments, Birkefeld compared plates peppered with lead oxide particles to ones with copper concentrate mined from Chile. Overall, the copper particles were extremely slow to degrade, whereas the lead particles dissolved in acidic soils and formed new phases in calcareous soils, according to Birkefeld. His method is a big advance on the mesh bag studies because it is rugged enough for soil and is quantitative, says Janet Hering, a professor at the California Institute of Technology. And because the method works in soil, she believes it would great for sediment studies too. Nowack says that future iron oxide studies will be in collaboration with the University of Rennes in France. They hope to answer questions that arose during Birkefeld’s study, including what specific processes contributed to particle degradation. —RACHEL PETKEWICH
