Catalyzing pollution ew research from several European teams suggests that the same catalytic converters that reduce harmful atmospheric pollution from automobiles may be creating a new environmental problem by widely broadcasting small amounts of the platinum group metals (PGM)—platinum, palladium, and rhodium—into the environment. A study by a French and Italian team led by Carlo Barbante at the University of Venice found increasing concentrations of PGM in Greenland snow and ice. The researchers attribute the trend to emissions from catalytic converters (Environ. Sci. Technol. 2001, 35 (5), 835–839). A second study hints that palladium is much more mobile in the environment than previously believed. English researchers, led by environmental chemist Kym Jarvis of Kingston University, report that more than one-third of the palladium in road dust is soluble in simulated rain (Environ. Sci. Technol. 2001, 35 (6), 1031–1036). The United States, Canada, and Japan introduced cars with catalytic converters in 1976. Europe followed in the late 1980s. The platinum and palladium in these devices catalyze oxidation reactions that convert carbon monoxide and hydrocarbons into less noxious emissions. Rhodium catalyzes reduction reactions that
convert NOx into less harmful gases. Scientists have been concerned for a number of years that the everincreasing use of automobile catalytic converters might lead to W earinside the honeycombed structure ofa catalytic widespread dispersion convertercan release metalsto the environment. of PGM into the environment, although Barbante calculates that emissions pg/g for platinum and palladium are currently low, about 0.5–1.4 and 7 × 10–4 pg/g for rhodium. The tons of platinum per year worldscientists attribute the increases to wide. catalytic converter emissions beThe recent studies, together with cause the time trends in Greenland an impending European Commissnow are similar to the PGM desion report, show that PGMs in the mand curves, says Barbante. The environment need attention now, increases are more likely to come according to environmental chemfrom refining and smelting operaist Gregory Morrison at Chalmers tions in Siberia, whose output also University of Technology in Götematches the time trends and eleborg, Sweden. “Levels now are very ment ratios, says Rob Searles, dilow, but the issue is what happens rector of the Association for as there are more cars and more Emissions Control by Catalyst, a converters. That’s why we need to trade group based in Brussels. pay attention to PGMs so that we Searles also notes that studies have can avoid a problem in the future,” shown that PGM particles, which he says. are relatively heavy, typically don’t Barbante and colleagues collecttravel far from car exhaust pipes ed snow and ice from central but fall out at the edges of roadGreenland and took samples from ways. the Greenland Ice Core Project, A number of studies have indeed which provides material dating shown increased PGM at the edges back more than 7700 years. They of major roadways, but it has been found PGM concentrations in samassumed the metals would be inert, ples from 1995 that are 40–120 says Jarvis. Her research shows that times higher than values in the anmore than one-third of the palladicient ice, which has values of 0.01 um in road dust is soluble in simulated rain, while only about 1% of platinum and rhodium are soluble. This suggests that some, if not all, of the palladium in road dust is in a form such as a chloride or oxide species, whereas platinum and rhodium are probably there as zero-valent metals, she says. The Jarvis study is important because it provides an explanation for how palladium is getting into the Researchersare using a laserablation system (left)and an inductivelycoupled plasma mass spectrometer(right)to studyplatinum group metalsassociated w ith catalytic converters. environment, says Morrison. SÉBASTIEN RAUCH
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Together with Sébastien Rauch, Morrison has found that palladium accumulates in the freshwater crustacean Asellus aquaticus. They have also found that the concentration of palladium has been increasing over time in the feathers of Swedish raptors. Although this new research suggests that PGMs in the environment may merit more scrutiny, the immi-
Government Watch
nent European Commission study finds that exposure to PGMs from automotive catalysts does not pose a human health risk. Ambient air levels of platinum, which range from 1 to 100 pg/m3, are several orders of magnitude below safe levels (calculated to be between 15 and 150 ng/m3). Levels of the other PGM metals in air are also very low. —REBECCA RENNER
Wetlands go dry? In a landmark 5–4 split decision on January 9, the U.S. Supreme Court struck down federal regulation of isolated ponds and wetlands. The court ruled that Congress did not intend the Clean Water Act (CWA) to apply to isolated waters such as prairie potholes and vernal pools. The decision could leave more than 20% of the nation’s wetlands, including cypress domes in the Everglades, vulnerable to drainage and filling, according to the National Wildlife Federation, an environmental group. The action was triggered 10 years ago when the U.S. Army Corps of Engineers denied a permit to the Solid Waste Agency of Northern Cook County (SWANCC), a consortium of 23 Illinois cities, to fill an abandoned strip mine with garbage. SWANCC sued the Corps, asserting that it had no right to regulate isolated wetlands because the CWA only covers waters that could be used for navigation or are connected to navigable waters. The Supreme Court agreed, adding that federal regulation of isolated wetlands would infringe on states’ rights.
Lake Michigan heavily contaminated with PBDEs been collected in Europe. Jon Manchester of the University of Wisconsin’s Water Chemistry Program has added to the U.S. database by using archived fish extract originally prepared for PCB analysis. “Other researchers could do the same,” he suggests, “contributing [to the] database [on PBDEs in the U.S.] very quickly.” Environmental PBDE contamination has raised significant concern in Europe, leading the European Commission to propose a ban on penta-BDE this past January. The proposal followed the advice given by the European Union (EU) in an extensive risk assessment on penta-BDE that was published last August (http://ecb.ei.jrc.it), which itself was prompted by the presence of penta-BDE in human breast milk and uncertainties regarding its health effects on infants. PBDEs are
EC action plan WISCONSIN SEA GRANT
Levels of polybrominated diphenyl ethers (PBDEs) in Lake Michigan salmon are among the highest ever reported for fish in open waters, providing further evidence that this class of compounds is a ubiquitous environmental threat (Environ. Sci. Technol. 2001, 35 (6), 1072–1077). PBDEs are used as flame retardants in polyurethane foam, textiles, and plastic electric and electronic components, with penta-, octa-, and deca-BDE as the most commonly used commercial preparations. PBDEs have only recently received attention as environmental pollutants, after they were detected in diverse environments ranging from the deep sea to human blood serum and breast milk (Environ Sci. Technol. 2000, 34 (9), 223A–226A). U.S. data on the prevalence of PBDEs in the environment are still scarce compared to data that have
PBDE concentrationsin salmon from Lake M ichigan are among the highestin the w orld forfish in open w aters,researchersfrom the UniversityofW isconsin revealed.
The Sixth Environmental Action Program (EAP), proposed by the European Commission (EC) in late January, outlines Europe’s course of action on the environment over the next 5 to 10 years. The new EAP is expected to receive a reading in the European parliament this month and then move on to the Environmental Council of Ministers. Under the program, the EC will work harder on implementing exContinued on Page 141A
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Environmental M News also targeted to be phased out under the recent and disputed EU proposals to restrict hazardous substances in electric and electronic equipment. The EU bromine industry is fighting to prevent bans on octa- and deca-BDE. Risk assessments on these two substances are imminent. Although deca-BDE accounts for 82% of the global BDE production, it is the smaller congeners— tetra-BDE and penta-BDE—that are most commonly found in humans and the environment. However, this is no reason to be more relaxed about deca- and octa-BDE, suggests Åke Bergman, professor for Environmental Chemistry at Stockholm University and one of the most experienced researchers on brominated flame retardants. He stresses that the commercial mixture sold as octaBDE, in fact, mainly consists of hexa- and hepta-BDE, and he is especially worried about deca-BDE’s high reactivity, which makes it
prone to act as a human carcinogen. He also suspects the lack of reliable data on deca-BDE in the environment is partly due to difficulties with its analysis. A comparison between PBDE and PCB levels in the Lake Michigan salmon used in the University of Wisconsin study show a high correlation, suggesting that PBDEs have also been around for at least one or two decades. Manchester therefore intends to investigate historical PBDE input into Lake Michigan by analyzing sediment, river, and air samples, and also to conduct a more detailed food chain analysis. “Personally, I feel uncomfortable with any anthropogenic compound building up in people and the environment,” Manchester states. Bergman is equally worried about PBDEs due to what he perceives as a general lack of knowledge on brominated compounds. “In my opinion, also octa- and deca-BDE don’t belong on the market.” —ANKE SCHAEFER
Fuel cell buses in developing countries As part of its ongoing strategy to introduce clean technologies and reduce greenhouse gas emissions in developing nations, the Global Environment Facility (GEF) has given a green light to the use of fuel cell buses in a demonstration project in five nations. Between 2002 and 2003, GEF plans to pay the incremental costs for the operation of 40–50 fuel cell buses in Sao Paulo, Brazil; Mexico City, Mexico; New Delhi, India; Cairo, Egypt; and Beijing and Shanghai, China, pending approval for the project from each country. Brazil is slated to be the first to use the fuel cell buses. The GEF, a multilateral trust fund, which works through the United Nation’s Development Programme (UNDP), the U.N.’s Environment Programme, and the World Bank, will contribute $60 million of the $130 million projected cost. Remaining costs will be picked up by the five countries, with a
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small amount contributed by private industry. Although the initial cost of fuel cell buses is substantial, the 33-member GEF is taking into consideration the eventual commercialization of the technology, which is projected to occur between 2007 and 2010, to drive down the price to a level that is competitive with conventional diesel engines. According to Richard Hosier, UNDP-GEF’s principal technical adviser on climate change, each country will need its own manufacturing infrastructure to increase production. “Once this happens,” he says, “the costs per bus will fall. This leaves two major areas of risk—one, if the actual performance of the fuel cells and the hydrogen supply falls short of expectation, and two, if the demand for these buses does not grow rapidly enough to push down the suppliers’ cost curve.” —PATRICIA E. DEMPSEY
ENVIRONMENTAL SCIENCE & TECHNOLOGY / APRIL 1, 2001
Greening the clean room Although semiconductors are produced in carefully controlled clean rooms, the process of making them can be a fairly dirty business, environmentally speaking. A new method that relies heavily on CO2 can simultaneously improve the performance of key parts of the photolithography process for creating silicon-based chips while reducing the amount of waste and toxicity associated with them. In time, it could render clean rooms obsolete for the semiconductor industry. Traditionally, applying, developing, and removing the thin polymer films that serve as masks, or patterns, for the circuits that will eventually be etched onto semiconductors requires the use of solvents and large quantities of water. The spin-coating and removal processes devised by Joseph DeSimone, a professor of chemistry and chemical engineering at both the University of North Carolina–Chapel Hill and North Carolina State University, are green because they use nontoxic chemicals, mainly CO2, and need no water, he says. Although the semiconductor industry is trying hard to reduce its environmental impact, DeSimone believes the major appeal of the new processes is their ability to circumvent problems that have become apparent as the industry moves toward smaller channels on larger wafers. Traditional solvents and water simply cannot consistently scour out channels that meet the tight specifications for the next generation of chips, says Robert Allen, manager of the Lithography Materials Research Department at IBM’s Almaden Research Center in San Jose, CA. With a 400-nm film, the capillary force of water can crush the narrow portions of these layers if their resolution is below 100 nm, explains Allen. This problem is known as pattern collapse, and Allen, in addition to a number of U.S. and Japanese researchers, is also trying to tackle this problem by using CO2.
IBM
Because CO2 allows much thinner channels to be carved out, another division of IBM, the T. J. Watson Research Center in Yorktown Hts., NY, is collaborating with DeSimone to develIn addition to being lesstoxic,a new CO2-based semiconducop his process, actortechnologycircumventsproblems,such asthe pattern colcording to Marie lapse thatcaused some ofthe channelsshow n in thisphoto to collapse,associated w ith using w aterand traditionalsolvents Angelopoulos, manin the photolithographyprocess. ager of the division’s Advanced Lithography Materials and Processes leads to a significant advantage Department. with large-performance gains.” The fact that DeSimone’s process Although Angelopoulos stresses requires no traditional solvents is imthat DeSimone’s integrated apportant because they are “related to proach is worth pursuing in the the health problems that have arisen long term, she says IBM is currently in the semiconductor industry over more interested in refining the step its short history,” says Ted Smith, exthat can avoid image collapse. ecutive director of the Silicon Valley DeSimone’s integrated process also Toxics Coalition, a nonprofit industry makes it easier to generate a uniwatchdog group. Both reproductive form and defect-free thin film atop problems and cancers are associated the larger 300-mm wafers, and the with workers’ exposure to solvents, film is easier to dissolve than some such as chlorinated hydrocarbons of the fluorinated polymers currentand glycol ethers, he says. These solly used in lithography. vents are used in the photolithograThe potential of DeSimone’s inphy process at older semiconductor tegrated approach to reduce the facilities, says Bill Baker, president of amount of water used in the photoBaker Associates, an industry conlithography process also has great sulting firm that DeSimone has reenvironmental significance, Smith tained. Angelopoulos adds that says. The industry has “an enorchlorinated solvents are no longer mous thirst for water resources— used in U.S. facilities. new semiconductor fabs going in By the time this article is pubare using millions of gallons of lished, DeSimone expects to have water a day,” he says, adding that announced the formation of a new water security is an increasingly imcompany, Micell Integrated portant issue in areas where chipSystems, to commercialize the new making facilities are located. photolithography technology. The In the long term, DeSimone says new company plans to offer an inthat his technology could “greatly tegrated approach to photolithogradecrease the need for” the clean phy technology that is dramatically room environments in which semidifferent from how the process is conductors are currently produced currently performed. DeSimone arbecause the new CO2-based gues that the time is ripe for a new processes can be completed withtechnology because the semiconout human intervention. That’s imductor industry is moving to larger portant because clean rooms 300-mm wafers, which will require represent half of the cost of running manufacturers to build entirely new a fab line, and they constitute the chip-fabrication lines, or “fabs”, as main route through which humans they are known in the industry. are exposed to potentially noxious Allen says that the conservative chemicals, he says. semiconductor industry is likely to If DeSimone's process delivers adopt a radically different manufacon its promise, it will definitely turing approach such as the one have groups like his in its corner, DeSimone has devised only “if it Smith says. —KELLYN S. BETTS
Government Watch isting environmental laws, integrating environmental policy more deeply and effectively into other policy areas from agriculture to economics, and involving both business and consumers in the decision-making process. These were listed as weaknesses in an assessment of the preceding EAP, which covered 1992 to 1999. The new program singles out four areas for particular emphasis—climate change, nature and biodiversity, environment and health, and natural resources and waste. But environmentalists and industry representatives, while expressing cautious support of the program, point out that only the climate change and waste policies have any targets listed at all.
U.K. trades with itself This month, the United Kingdom (U.K.) is poised to become the first country actively trading CO2 emissions, according to the U.K.’s Department of the Environment, Transport and the Regions. The country has no trading partners, but it is undertaking the program in hopes it will “kick start” international trading, says Michael Meacher, environment minister for the department. Although quick to praise the emissions trading program for leading the world, some observers are concerned that it will conflict with other U.K. policies aimed at greenhouse gas reductions, the Climate Change Levy, and the Renewables Obligation. “We have moved from energy efficiency to emissions trading, but [the situation is] complicated by the fact that the generators (utilities) are not included and seem unlikely to come in the first round,” explains Charles Crosthwaite Eyre, director of Carbon Risk Management for Aon Limited, a firm that is insuring the price of carbon credits for emissions trading.
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Environmental M News Stopping invasive species
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fish are dumped into nearby streams all too often. Although there are no hard numbers, the potential is huge. “Each year, more than 2000 non-native fish species, representing nearly 150 million exotic freshwater and marine fishes, are imported into the United States for use in aquarium trade,” she says. Experts agree that the first step in stopping invasive species is to prevent them from leaving home in the first place. “We need to identify the pathways of movement and then block them,” says Lyons. “But
PHOTODISC
Preventing the movement of invasive alien species, rather than dealing with them once they have been established and have made an economic impact, is key to sustaining global biodiversity and environmental resources, according to a panel of experts at a February symposium presented at the American Association for the Advancement of Science (AAAS) meeting in San Francisco, CA. Around the world, the number of non-native species continues to increase every year due to globalization. Considering how little is known about viruses and other microbes, the number is likely to be grossly underestimated, says David Lodge of the University of Notre Dame, who studies invasive species in the Great Lakes. Although regional efforts to combat invasive species are important, experts agree that integration of those efforts at the global level is necessary. As Helida Oyieke, an aquatic ecologist and assistant director of the Centre for Biodiversity at the National Museums of Kenya puts it, “We are all in this together.” There are ~50,000 invasive alien species in the United States alone, causing $123 billion in damage annually, according to Elizabeth Lyons of the U.S. National Science Foundation, one of the organizers of the symposium. Globally, that cost is more than $500 billion per year, she says. Ballast water, canals, aquaculture, and fish stocking have long been blamed for introducing invasive alien species into the environment; but other, less obvious sources such as live bait, recreational and fishing boats, and the aquarium, garden, biological supply, and live-food trades, are also contributing to the problem, says Lodge. According to Pam Fuller of the U.S. Geological Survey in Gainesville, FL, exotic aquarium
tribution of species, but the taxonomic data that do exist are not available to those who need them most, says Scott Miller of the Smithsonian Institution’s National Museum of Natural History. “We have approximately 300 years of biodiversity data scattered throughout the world in the literature in many languages, and there are about 8 billion specimens worldwide in museums,” he says. But access to those data is limited and not readily available to those involved in management decisions, he explains. Countries around the world are currently in different stages of handling the invasive species problem. Whereas the United States, Europe, Australia, New Zealand, and some African regions have begun addressing the issue, other countries are not even aware of the problem. To help countries, particularly developing countries, become more aware of invasive species and deal with them, a coalition of scientists, economists, lawyers, social scientists, conservationists, and resource managers, called the Global Invasive Species Programme (GISP), was formed in 1997. Phase one of the program, which was to develop a global-scale strategy document to guide policy makers, has just been completed, says Harold Mooney, past-chair of GISP and professor at Stanford University. Details of that strategy were highlighted at the AAAS symposium. High on the list are international cooperation; the development of rapid, international response mechanisms; increased public awareness; the development of a system of environmental risk analysis; and warning systems for sharing information as soon as invasive species appear. According to Mooney, the second phase of GISP, implementation of the strategy, is just beginning. More information about GISP can be found at http://jasper.stanford.edu/gisp. —BRITT E. ERICKSON
first we need to determine what species are there,” says Keith Hayes, an invasive species risk analyst at the CSIRO Centre for Research on Introduced Marine Pests in Australia. “Many Australian ports have yet to be surveyed,” he says. “With new tools such as genetic probes, we will eventually be able to determine what organisms are in things like ballast water,” he adds. Not only is there a lack of knowledge regarding the worldwide dis-
ENVIRONMENTAL SCIENCE & TECHNOLOGY / APRIL 1, 2001
News M Briefs A voluntary agreement between the automobile industry and the European Commission to reduce CO2 emissions lacks ambition and is unenforceable, states the European Environmental Bureau (EEB), Europe’s largest environmental coalition, in a recent report. According to the agreement, European auto manufacturers will reduce average new car emissions by 25% to 140 g CO2/km by 2008, with an interim target of 165 g CO2/km by 2003. But EEB contends that a 40% reduction would be more in line with Europe’s commitments under the Kyoto Protocol. The analysis of the voluntary fuel economy agreement can be accessed at www.eeb.org. Global warming caused by emissions of CO2 and other greenhouse
gases could cost the world more than $300 billion annually by 2050, according to a report by Munich Re, a leading German reinsurance company that monitors the costs of natural disasters. The report predicts that climate change will cause more frequent tropical cyclones, flooding due to rising sea levels, and damage to food and water supplies. Although most countries can expect losses to be no more than a few percent of their gross domestic products, low-lying islands could be faced with losses in excess of 10% of their national wealth, if CO2 levels in the atmosphere reach twice that of the preindustrial age. To obtain a copy of Climatic Change: Effects on and Possible Responses by the Insurance Industry, contact Munich Re at www.munichre.com.
Stabilizing population through good quality family planning services would buy some extra time to make improvements in technology for protecting natural resources, concludes a report from the Johns Hopkins School of Public Health. Although the rate of population growth has slowed over the past few decades, the absolute number of people continues to increase by about 1 billion every 13 years, with most of the growth occurring in the developing world. At the same time, the environment continues to deteriorate. The report urges governments to implement sustainable development policies, of which human population stabilization is a key focal point. Population and the Environment: The Global Challenge can be viewed at www.jhuccp.org.
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