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New research from severalEuropean teams suggests thatthe same catalytic converters

that reduce harmful atmosphericpollution from automobiles may becreating a new environmentalproblem by widely broadcastingsmall amounts of the platinumgroup metals (PGM)—platinum,palladium, and rhodium—into theenvironment.

A study by a French and Italianteam led by Carlo Barbante at theUniversity of Venice found increas-ing concentrations of PGM inGreenland snow and ice. The re-searchers attribute the trend toemissions from catalytic converters(Environ. Sci. Technol. 2001, 35 (5),835–839). A second study hints thatpalladium is much more mobile inthe environment than previouslybelieved. English researchers, led byenvironmental chemist Kym Jarvisof Kingston University, report thatmore than one-third of the palladi-um in road dust is soluble in simu-lated rain (Environ. Sci. Technol.2001, 35 (6), 1031–1036).

The United States, Canada, andJapan introduced cars with catalyt-ic converters in 1976. Europe fol-lowed in the late 1980s. Theplatinum and palladium in thesedevices catalyze oxidation reac-tions that convert carbon monox-ide and hydrocarbons into lessnoxious emissions. Rhodium cat-alyzes reduction reactions that

convert NOx into lessharmful gases.

Scientists have beenconcerned for a numberof years that the ever-increasing use of auto-mobile catalytic con-verters might lead towidespread dispersionof PGM into the envi-ronment, althoughBarbante calculates that emissionsare currently low, about 0.5–1.4tons of platinum per year world-wide.

The recent studies, together withan impending European Commis-sion report, show that PGMs in theenvironment need attention now,according to environmental chem-ist Gregory Morrison at ChalmersUniversity of Technology in Göte-borg, Sweden. “Levels now are verylow, but the issue is what happensas there are more cars and moreconverters. That’s why we need topay attention to PGMs so that wecan avoid a problem in the future,”he says.

Barbante and colleagues collect-ed snow and ice from centralGreenland and took samples fromthe Greenland Ice Core Project,which provides material datingback more than 7700 years. Theyfound PGM concentrations in sam-ples from 1995 that are 40–120times higher than values in the an-cient ice, which has values of 0.01

pg/g for platinum and palladiumand 7 × 10–4 pg/g for rhodium. Thescientists attribute the increases tocatalytic converter emissions be-cause the time trends in Greenlandsnow are similar to the PGM de-mand curves, says Barbante. Theincreases are more likely to comefrom refining and smelting opera-tions in Siberia, whose output alsomatches the time trends and ele-ment ratios, says Rob Searles, di-rector of the Association forEmissions Control by Catalyst, atrade group based in Brussels.Searles also notes that studies haveshown that PGM particles, whichare relatively heavy, typically don’ttravel far from car exhaust pipesbut fall out at the edges of road-ways.

A number of studies have indeedshown increased PGM at the edgesof major roadways, but it has beenassumed the metals would be inert,says Jarvis. Her research shows thatmore than one-third of the palladi-um in road dust is soluble in simu-lated rain, while only about 1% ofplatinum and rhodium are soluble.This suggests that some, if not all,of the palladium in road dust is in aform such as a chloride or oxidespecies, whereas platinum andrhodium are probably there aszero-valent metals, she says.

The Jarvis study is important be-cause it provides an explanation forhow palladium is getting into theenvironment, says Morrison.

Environmental�News

Catalyzing pollution

W earinsidethehoneycombedstructureofacatalyticconvertercanreleasemetalstotheenvironment.

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Researchersareusingalaserablationsystem (left)andaninductivelycoupledplasmamassspectrometer(right)tostudyplatinum groupmetalsassociatedwithcatalyticconverters.

138 A � ENVIRONMENTAL SCIENCE & TECHNOLOGY / APRIL 1, 2001

Together with Sébastien Rauch,Morrison has found that palladiumaccumulates in the freshwater crus-tacean Asellus aquaticus. They havealso found that the concentrationof palladium has been increasingover time in the feathers of Swedishraptors.

Although this new research sug-gests that PGMs in the environmentmay merit more scrutiny, the immi-

nent European Commission studyfinds that exposure to PGMs fromautomotive catalysts does not posea human health risk. Ambient airlevels of platinum, which rangefrom 1 to 100 pg/m3, are several or-ders of magnitude below safe levels(calculated to be between 15 and150 ng/m3). Levels of the otherPGM metals in air are also very low.—REBECCA RENNER

Wetlands go dry?In a landmark 5–4 split decision onJanuary 9, the U.S. Supreme Courtstruck down federal regulation ofisolated ponds and wetlands. Thecourt ruled that Congress did notintend the Clean Water Act (CWA)to apply to isolated waters such asprairie potholes and vernal pools.The decision could leave morethan 20% of the nation’s wetlands,including cypress domes in theEverglades, vulnerable to drainageand filling, according to theNational Wildlife Federation, anenvironmental group.

The action was triggered 10years ago when the U.S. ArmyCorps of Engineers denied a permitto the Solid Waste Agency ofNorthern Cook County (SWANCC),a consortium of 23 Illinois cities, tofill an abandoned strip mine withgarbage. SWANCC sued the Corps,asserting that it had no right toregulate isolated wetlands be-cause the CWA only covers wa-ters that could be used fornavigation or are connected tonavigable waters. The SupremeCourt agreed, adding that federalregulation of isolated wetlandswould infringe on states’ rights.

EC action planThe Sixth Environmental ActionProgram (EAP), proposed by theEuropean Commission (EC) in lateJanuary, outlines Europe’s courseof action on the environment overthe next 5 to 10 years. The newEAP is expected to receive a read-ing in the European parliament thismonth and then move on to theEnvironmental Council of Ministers.

Under the program, the EC willwork harder on implementing ex-

Levels of polybrominated diphenylethers (PBDEs) in Lake Michigansalmon are among the highest everreported for fish in open waters,providing further evidence that thisclass of compounds is a ubiquitousenvironmental threat (Environ. Sci.Technol. 2001, 35 (6), 1072–1077).PBDEs are used as flame retardantsin polyurethane foam, textiles, andplastic electric and electronic com-ponents, with penta-, octa-, anddeca-BDE as the most commonlyused commercial preparations.

PBDEs have only recently re-ceived attention as environmentalpollutants, after they were detectedin diverse environments rangingfrom the deep sea to human bloodserum and breast milk (Environ Sci.Technol. 2000, 34 (9), 223A–226A).U.S. data on the prevalence ofPBDEs in the environment are stillscarce compared to data that have

been collected in Europe. JonManchester of the University ofWisconsin’s Water ChemistryProgram has added to the U.S. data-base by using archived fish extractoriginally prepared for PCB analysis.“Other researchers could do thesame,” he suggests, “contributing [tothe] database [on PBDEs in the U.S.]very quickly.”

Environmental PBDE contamina-tion has raised significant concernin Europe, leading the EuropeanCommission to propose a ban onpenta-BDE this past January. Theproposal followed the advice givenby the European Union (EU) in anextensive risk assessment on pen-ta-BDE that was published lastAugust (http://ecb.ei.jrc.it), whichitself was prompted by the presenceof penta-BDE in human breast milkand uncertainties regarding itshealth effects on infants. PBDEs are

Government Watch

Lake Michigan heavily contaminated with PBDEs

PBDEconcentrationsinsalmonfrom LakeM ichiganareamongthehighestintheworldforfishinopenwaters,researchersfrom theUniversityofW isconsinrevealed.

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also targeted to be phased outunder the recent and disputed EUproposals to restrict hazardous sub-stances in electric and electronicequipment. The EU bromine indus-try is fighting to prevent bans onocta- and deca-BDE. Risk assess-ments on these two substances areimminent.

Although deca-BDE accountsfor 82% of the global BDE produc-tion, it is the smaller congeners—tetra-BDE and penta-BDE—thatare most commonly found in hu-mans and the environment.However, this is no reason to bemore relaxed about deca- andocta-BDE, suggests Åke Bergman,professor for EnvironmentalChemistry at Stockholm Universityand one of the most experiencedresearchers on brominated flameretardants. He stresses that thecommercial mixture sold as octa-BDE, in fact, mainly consists ofhexa- and hepta-BDE, and he is es-pecially worried about deca-BDE’shigh reactivity, which makes it

prone to act as a human carcino-gen. He also suspects the lack ofreliable data on deca-BDE in theenvironment is partly due to diffi-culties with its analysis.

A comparison between PBDEand PCB levels in the Lake Michigansalmon used in the University ofWisconsin study show a high corre-lation, suggesting that PBDEs havealso been around for at least one ortwo decades. Manchester thereforeintends to investigate historicalPBDE input into Lake Michigan byanalyzing sediment, river, and airsamples, and also to conduct amore detailed food chain analysis.“Personally, I feel uncomfortablewith any anthropogenic compoundbuilding up in people and the envi-ronment,” Manchester states.Bergman is equally worried aboutPBDEs due to what he perceives asa general lack of knowledge onbrominated compounds. “In myopinion, also octa- and deca-BDEdon’t belong on the market.”—ANKE SCHAEFER



Although semiconductors are pro-duced in carefully controlled cleanrooms, the process of making themcan be a fairly dirty business, envi-ronmentally speaking. A newmethod that relies heavily on CO2can simultaneously improve the per-formance of key parts of the pho-tolithography process for creatingsilicon-based chips while reducingthe amount of waste and toxicity as-sociated with them. In time, it couldrender clean rooms obsolete for thesemiconductor industry.

Traditionally, applying, develop-ing, and removing the thin polymerfilms that serve as masks, orpatterns, for the circuits that willeventually be etched onto semicon-ductors requires the use of solventsand large quantities of water. Thespin-coating and removal processesdevised by Joseph DeSimone, a pro-fessor of chemistry and chemicalengineering at both the Universityof North Carolina–Chapel Hill andNorth Carolina State University, aregreen because they use nontoxicchemicals, mainly CO2, and need nowater, he says.

Although the semiconductor in-dustry is trying hard to reduce itsenvironmental impact, DeSimonebelieves the major appeal of thenew processes is their ability to cir-cumvent problems that have be-come apparent as the industrymoves toward smaller channels onlarger wafers. Traditional solventsand water simply cannot consis-tently scour out channels that meetthe tight specifications for the nextgeneration of chips, says RobertAllen, manager of the LithographyMaterials Research Department atIBM’s Almaden Research Center inSan Jose, CA.

With a 400-nm film, the capillaryforce of water can crush the narrowportions of these layers if their res-olution is below 100 nm, explainsAllen. This problem is known aspattern collapse, and Allen, in addi-tion to a number of U.S. andJapanese researchers, is also tryingto tackle this problem by using CO2.

Greening theclean room

As part of its ongoing strategy tointroduce clean technologies andreduce greenhouse gas emissionsin developing nations, the GlobalEnvironment Facility (GEF) hasgiven a green light to the use offuel cell buses in a demonstrationproject in five nations.

Between 2002 and 2003, GEFplans to pay the incremental costsfor the operation of 40–50 fuel cellbuses in Sao Paulo, Brazil; MexicoCity, Mexico; New Delhi, India;Cairo, Egypt; and Beijing andShanghai, China, pending ap-proval for the project from eachcountry. Brazil is slated to be thefirst to use the fuel cell buses. TheGEF, a multilateral trust fund,which works through the UnitedNation’s Development Programme(UNDP), the U.N.’s EnvironmentProgramme, and the World Bank,will contribute $60 million of the$130 million projected cost.

Remaining costs will be pickedup by the five countries, with a

small amount contributed by pri-vate industry.

Although the initial cost offuel cell buses is substantial, the33-member GEF is taking intoconsideration the eventual com-mercialization of the technology,which is projected to occur be-tween 2007 and 2010, to drivedown the price to a level that iscompetitive with conventionaldiesel engines. According toRichard Hosier, UNDP-GEF’s prin-cipal technical adviser on climatechange, each country will need itsown manufacturing infrastructureto increase production. “Once thishappens,” he says, “the costs perbus will fall. This leaves two majorareas of risk—one, if the actualperformance of the fuel cells andthe hydrogen supply falls short ofexpectation, and two, if the de-mand for these buses does notgrow rapidly enough to pushdown the suppliers’ cost curve.”—PATRICIA E. DEMPSEY

Fuel cell buses in developing countries


isting environmental laws, integrat-ing environmental policy moredeeply and effectively into otherpolicy areas from agriculture toeconomics, and involving bothbusiness and consumers in thedecision-making process. Thesewere listed as weaknesses in anassessment of the preceding EAP,which covered 1992 to 1999.

The new program singles outfour areas for particular empha-sis—climate change, nature andbiodiversity, environment andhealth, and natural resources andwaste. But environmentalists andindustry representatives, while ex-pressing cautious support of theprogram, point out that only the cli-mate change and waste policieshave any targets listed at all.

U.K. trades with itselfThis month, the United Kingdom(U.K.) is poised to become the firstcountry actively trading CO2 emis-sions, according to the U.K.’sDepartment of the Environment,Transport and the Regions. Thecountry has no trading partners,but it is undertaking the programin hopes it will “kick start” inter-national trading, says MichaelMeacher, environment minister forthe department.

Although quick to praise theemissions trading program forleading the world, some observersare concerned that it will conflictwith other U.K. policies aimed atgreenhouse gas reductions, theClimate Change Levy, and theRenewables Obligation. “We havemoved from energy efficiency toemissions trading, but [the situa-tion is] complicated by the fact thatthe generators (utilities) are not in-cluded and seem unlikely to comein the first round,” explains CharlesCrosthwaite Eyre, director ofCarbon Risk Management for AonLimited, a firm that is insuring theprice of carbon credits for emis-sions trading.

Government WatchBecause CO2 allowsmuch thinner chan-nels to be carved out,another division ofIBM, the T. J. WatsonResearch Center inYorktown Hts., NY, iscollaborating withDeSimone to devel-op his process, ac-cording to MarieAngelopoulos, man-ager of the division’sAdvanced LithographyMaterials and ProcessesDepartment.

The fact that DeSimone’s processrequires no traditional solvents is im-portant because they are “related tothe health problems that have arisenin the semiconductor industry overits short history,” says Ted Smith, ex-ecutive director of the SiliconValleyToxics Coalition, a nonprofit industrywatchdog group. Both reproductiveproblems and cancers are associatedwith workers’ exposure to solvents,such as chlorinated hydrocarbonsand glycol ethers, he says. These sol-vents are used in the photolithogra-phy process at older semiconductorfacilities, says Bill Baker, president ofBaker Associates, an industry con-sulting firm that DeSimone has re-tained. Angelopoulos adds thatchlorinated solvents are no longerused in U.S. facilities.

By the time this article is pub-lished, DeSimone expects to haveannounced the formation of a newcompany, Micell IntegratedSystems, to commercialize the newphotolithography technology. Thenew company plans to offer an in-tegrated approach to photolithogra-phy technology that is dramaticallydifferent from how the process iscurrently performed. DeSimone ar-gues that the time is ripe for a newtechnology because the semicon-ductor industry is moving to larger300-mm wafers, which will requiremanufacturers to build entirely newchip-fabrication lines, or “fabs”, asthey are known in the industry.Allen says that the conservativesemiconductor industry is likely toadopt a radically different manufac-turing approach such as the oneDeSimone has devised only “if it

leads to a significant advantagewith large-performance gains.”

Although Angelopoulos stressesthat DeSimone’s integrated ap-proach is worth pursuing in thelong term, she says IBM is currentlymore interested in refining the stepthat can avoid image collapse.DeSimone’s integrated process alsomakes it easier to generate a uni-form and defect-free thin film atopthe larger 300-mm wafers, and thefilm is easier to dissolve than someof the fluorinated polymers current-ly used in lithography.

The potential of DeSimone’s in-tegrated approach to reduce theamount of water used in the photo-lithography process also has greatenvironmental significance, Smithsays. The industry has “an enor-mous thirst for water resources—new semiconductor fabs going inare using millions of gallons ofwater a day,” he says, adding thatwater security is an increasingly im-portant issue in areas where chip-making facilities are located.

In the long term, DeSimone saysthat his technology could “greatlydecrease the need for” the cleanroom environments in which semi-conductors are currently producedbecause the new CO2-basedprocesses can be completed with-out human intervention. That’s im-portant because clean roomsrepresent half of the cost of runninga fab line, and they constitute themain route through which humansare exposed to potentially noxiouschemicals, he says.

If DeSimone's process deliverson its promise, it will definitelyhave groups like his in its corner,Smith says. —KELLYN S. BETTS

Inadditiontobeinglesstoxic,anew CO2-basedsemiconduc-tortechnologycircumventsproblems,suchasthepatterncol-lapsethatcausedsomeofthechannelsshowninthisphototocollapse,associatedwithusingwaterandtraditionalsolventsinthephotolithographyprocess.

IBM

Preventing the movement of inva-sive alien species, rather than deal-ing with them once they have beenestablished and have made an eco-nomic impact, is key to sustainingglobal biodiversity and environ-mental resources, according to apanel of experts at a February sym-posium presented at the AmericanAssociation for the Advancement ofScience (AAAS) meeting in SanFrancisco, CA.

Around the world, the numberof non-native species continues toincrease every year due to global-ization. Considering how little isknown about viruses andother microbes, the numberis likely to be grossly underes-timated, says David Lodge ofthe University of Notre Dame,who studies invasive speciesin the Great Lakes. Althoughregional efforts to combat in-vasive species are important,experts agree that integrationof those efforts at the globallevel is necessary. As HelidaOyieke, an aquatic ecologistand assistant director of theCentre for Biodiversity at theNational Museums of Kenyaputs it, “We are all in thistogether.”

There are ~50,000 invasivealien species in the UnitedStates alone, causing $123 bil-lion in damage annually, ac-cording to Elizabeth Lyons ofthe U.S. National ScienceFoundation, one of the orga-nizers of the symposium.Globally, that cost is more than$500 billion per year, she says.

Ballast water, canals, aquacul-ture, and fish stocking have longbeen blamed for introducing inva-sive alien species into the environ-ment; but other, less obvioussources such as live bait, recre-ational and fishing boats, and theaquarium, garden, biological sup-ply, and live-food trades, are alsocontributing to the problem, saysLodge. According to Pam Fuller ofthe U.S. Geological Survey inGainesville, FL, exotic aquarium

fish are dumped into nearbystreams all too often. Althoughthere are no hard numbers, the po-tential is huge. “Each year, morethan 2000 non-native fish species,representing nearly 150 million ex-otic freshwater and marine fishes,are imported into the United Statesfor use in aquarium trade,” shesays.

Experts agree that the first stepin stopping invasive species is toprevent them from leaving home inthe first place. “We need to identifythe pathways of movement andthen block them,” says Lyons. “But

first we need to determine whatspecies are there,” says Keith Hayes,an invasive species risk analyst atthe CSIRO Centre for Research onIntroduced Marine Pests inAustralia. “Many Australian portshave yet to be surveyed,” he says.“With new tools such as geneticprobes, we will eventually be ableto determine what organisms are inthings like ballast water,” he adds.

Not only is there a lack of knowl-edge regarding the worldwide dis-

tribution of species, but the taxo-nomic data that do exist are notavailable to those who need themmost, says Scott Miller of theSmithsonian Institution’s NationalMuseum of Natural History. “Wehave approximately 300 years ofbiodiversity data scattered through-out the world in the literature inmany languages, and there areabout 8 billion specimens world-wide in museums,” he says. But ac-cess to those data is limited and notreadily available to those involvedin management decisions, heexplains.

Countries around the world arecurrently in different stages of han-dling the invasive species problem.

Whereas the United States,Europe, Australia, NewZealand, and some African re-gions have begun addressingthe issue, other countries arenot even aware of the prob-lem. To help countries, partic-ularly developing countries,become more aware of inva-sive species and deal withthem, a coalition of scientists,economists, lawyers, socialscientists, conservationists,and resource managers, calledthe Global Invasive SpeciesProgramme (GISP), wasformed in 1997. Phase one ofthe program, which was to de-velop a global-scale strategydocument to guide policymakers, has just been com-pleted, says Harold Mooney,past-chair of GISP and profes-sor at Stanford University.Details of that strategy werehighlighted at the AAAS sym-posium. High on the list areinternational cooperation; the

development of rapid, internationalresponse mechanisms; increasedpublic awareness; the developmentof a system of environmental riskanalysis; and warning systems forsharing information as soon as in-vasive species appear. According toMooney, the second phase of GISP,implementation of the strategy, isjust beginning. More informationabout GISP can be found athttp://jasper.stanford.edu/gisp.—BRITT E. ERICKSON



Stopping invasive species

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A voluntary agreement betweenthe automobile industry and theEuropean Commission to reduceCO2 emissions lacks ambition andis unenforceable, states theEuropean Environmental Bureau(EEB), Europe’s largest environmen-tal coalition, in a recent report.According to the agreement,European auto manufacturers willreduce average new car emissionsby 25% to 140 g CO2/km by 2008,with an interim target of 165 gCO2/km by 2003. But EEB contendsthat a 40% reduction would bemore in line with Europe’s commit-ments under the Kyoto Protocol.The analysis of the voluntary fueleconomy agreement can be ac-cessed at www.eeb.org.

Global warming caused by emis-sions of CO2 and other greenhouse

gases could cost the world morethan $300 billion annually by2050, according to a report byMunich Re, a leading German rein-surance company that monitors thecosts of natural disasters. The re-port predicts that climate changewill cause more frequent tropicalcyclones, flooding due to rising sealevels, and damage to food andwater supplies. Although mostcountries can expect losses to be nomore than a few percent of theirgross domestic products, low-lyingislands could be faced with lossesin excess of 10% of their nationalwealth, if CO2 levels in the atmos-phere reach twice that of the pre-industrial age. To obtain a copy ofClimatic Change: Effects on andPossible Responses by the InsuranceIndustry, contact Munich Re atwww.munichre.com.

Stabilizing population throughgood quality family planning ser-vices would buy some extra timeto make improvements in tech-nology for protecting natural re-sources, concludes a report fromthe Johns Hopkins School of PublicHealth. Although the rate of popu-lation growth has slowed over thepast few decades, the absolutenumber of people continues to in-crease by about 1 billion every 13years, with most of the growth oc-curring in the developing world. Atthe same time, the environmentcontinues to deteriorate. The reporturges governments to implementsustainable development policies,of which human population stabi-lization is a key focal point.Population and the Environment:The Global Challenge can be viewedat www.jhuccp.org.

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