A 390 VOLUME 110 | NUMBER 7 | July 2002 • Environmental Health Perspectives

Up a ChemicalCreekA federal agency’s survey of 95 chemicals inU.S. rivers and streams has unveiled what thesurvey’s leader calls “a real cocktail of variouscompounds.” The chemicals studied includ-ed antibiotics, other prescription drugs,pesticides, and household chemicalssuch as detergents and fragrances. TheU.S. Geological Survey (USGS)found median concentrations thatusually were relatively low, but somemaximum concentrations were highand occasionally exceeded regulatoryguidelines for the few such chemicalsthat have them. This study of everydayproducts in U.S. waters, the most extensiveconducted so far, adds to thegrowing body of informa-tion on the topic,which includes workpublished in EHPSupplements in De-cember 1999.

The samplesites aren’t neces-sarily representativeof the country’s water-ways. Most sampleswere taken immediatelydownstream from suspectedpollution sources, such as wastewater treat-ment plants, urban areas, or agriculturaloperations. However, eight were takenin less-polluted settings.

The chemicals chosen for theUSGS study were known to be usedin significant quantities, were suspect-ed of being in the environment andaffecting environmental health, andcould be cost-effectively evaluated atlow concentrations. The study, which ranthrough 1999 and 2000 and was publishedin the 15 March 2002 issue of EnvironmentalScience & Technology, focused on establishingthe first snapshot of concentrations of theselected chemicals; it made no attempt toassess the implications of the findings regard-ing human health or ecologic systems.

At each of 139 sites in 30 states, one com-posite sample was drawn from 4–6 stratawithin a cross-section of the waterway. Of the95 chemicals evaluated, 82 showed up in atleast one sample. A mixture of 7 or moreshowed up in 50% of the streams, and 34% ofthe streams revealed a mixture of 10 or more.

The chemicals found most frequently weresteroids (from plant and animal sources), caf-feine, and components of insect repellent, dis-infectants, and fire retardants. The medianconcentration detected for each group of chem-icals was always less than 1.0 µg/L, but someindividual samples were much higher. The

maximum reading for deter-gent metabolites was 55.6

µg/L, steroids reach-ed a peak of 18.3µg/L, and plastici-zers topped out at17.4 µg/L.

While little is knownabout the environmental health effects ofmany of the chemicals, 46 are known to bepharmacologically active, and 33 are known tobe hormonally active. That’s a particular con-cern to Rebecca Goldburg, a senior scientistwith the advocacy organization Environ-mental Defense, because she says such sub-stances can have a biologic impact at very lowdoses. But Mark Grayson, senior director ofpublic affairs for the Washington, D.C.–basedPharmaceutical Research and Manufacturersof America, says his organization maintains its

position that no adverse environmental effectshave ever been proven at these concentrations.U.S. Food and Drug Administration spokes-man Brad Stone says the study causes hisagency no immediate concern, but that theagency is reviewing the findings to determineif any targeted follow-up studies are needed.

USGS researchers are analyzing their datato better understand their nuances, such asthe differences between urban, agricultural,and more naturalistic sites, and hope to pub-lish their findings by the beginning of 2003.Two of their parallel studies, one of chemicalcontaminants in wells and another of surfaceand groundwater drinking sources, also areunder way and may be published in the same

time frame.The USGS has a five-year plan

for similar studies, looking atmany of the issues that were

ignored or only touched uponin this study. Potential top-ics include specific path-ways of contamination,daily and seasonal varia-tions in concentrations,degradation products ofchemicals, and concen-trations in sediment andthe atmosphere. In addi-tion, Dana Kolpin, the

study’s project chief anda research hydrologist

with the USGS ToxicSubstances Hydrology Pro-

gram, says his team already isable to test for more than two

dozen additional chemicals. But President Bush’s fiscal year 2003

budget cuts the entire $13.9 million budgetfor the Toxic Substances Hydrology Program.“It’s possible this project may get terminated,”Kolpin acknowledges. The potential trade-offis a $10 million boost in research through theNational Science Foundation. But USGSinsiders think government agencies are unlike-ly to use those monies, because federal salariesaren’t covered by such funds. However,Congress may reinstate the USGS funding, asit did last year.

Other organizations are picking up theball on some of the angles covered in thisstudy. Researchers at The Johns HopkinsUniversity announced in April 2002 that witha three-year $525,000 grant from the U.S.Environmental Protection Agency they arebeginning to look at the environmental fate of200 of the most commonly used drugs.–Bob Weinhold

All science as it grows toward perfection becomes mathematical in its ideas.Alfred North Whitehead, mathematician/philosopher

(1861–1947)

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Not so pure water.An extensive studyof U.S. waters turnsup a chemical cock-tail including drugs,detergents, pesti-cides, and more.

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Environmental Health Perspectives • VOLUME 110 | NUMBER 7 | July 2002 A 391

The Beatedited by Erin E. Dooley

Big Chill in FridgeRecyclingA new regulation requiring the recovery ofchlorofluorocarbons (CFCs) and hydrochlo-rofluorocarbons (HCFCs) from refrigeratorshas caused the United Kingdom to adopt newcontrol procedures and build new recyclingfacilities on very short notice. The UnitedKingdom disposes of about 2.5 million con-sumer fridges and half a million larger com-mercial fridges each year. From a handlingprocess that saw 40% of discarded fridges stillin working order exported to developingcountries and the rest degassed and recycledas scrap metal, the nation is moving quicklytoward recycling all fridges domestically andcontrolling all related forms of ozone-deplet-ing substances for proper disposal.

The stage for change was set by the 1987Montreal Protocol on Substances that Depletethe Ozone Layer, which identified CFCs andHCFCs as ozone-depleting substances. In re-sponse, the European Commission adoptedRegulation 2037/2000, which requires mem-bers of the European Union to remove allsuch substances from refrigeration equipmentbefore it is scrapped.

CFCs and HCFCs are found in two com-ponents of fridges. About 20–25% is gaseous,mixed with oils and used in piping as acoolant. The rest is used as a propellant in thefoam insulation inside the fridge body anddoor. Most manufac-turers stopped usingCFCs as refrigerants inthe mid-1990s, butHCFCs continued tobe used as a propellantfor several years after.The coolant form hasalways been removedbefore recycling themetal, but until recent-ly there were no U.K.scrap facilities capa-ble of capturing theCFCs and HCFCs inthe foam.

Regulation 2037/2000 was issued inJune 2000, with acompliance date fordomestic fridges of 1January 2002. But questions over theextent and means of compliance draggedon for a year before the commission clari-fied that all forms of CFCs and HCFCsmust be removed and treated as hazardouswaste, usually by incineration. With initial

confusion over who would recycle thefridges and where they could be stored,news stories surfaced of farmers finding oldfridges dumped on their property.

At the same time, to clarify fridge han-dling procedures, the U.K. Department forEnvironment, Food, and Rural Affairs(DEFRA) and the U.K. Environment Agencyissued guidelines for temporary storage andprocessing to local authorities and recyclingcompanies. They also encouraged severalscrap metal companies to set up properlyequipped facilities, and facilitated the exportof some fridges to Germany, which has therecycling capacity to handle them.

Getting new fridge recycling plants capa-ble both of capturing the CFCs and HCFCsto a suitable standard and of scrapping themetal and other components has been themost pressing issue. The German companySEG is now operating two mobile plants inthe United Kingdom, and fixed plants will berunning by summer in North London, SouthWales, and the Liverpool area. DEFRA esti-mates that about 10–12 such plants will beneeded to work through the fridge backlogand make the country self-sufficient.

European Metal Recycling runs theNorth London facility, which can store largenumbers of units and process about 300,000per year. As a major European recycling cor-poration, they see grounds for more expan-sion as the market for scrap metal and forCFC/HCFC processing evolves.

Ozone Friends, a London communityservice group, is feeling other impacts of the

regulation. Executivedirector Mike Jennsays the group oncemade money byextracting and resellingrefrigerant gases fromdiscarded fridges.They also refurbishedthe units for sale at dis-count in low-incomecommunities. Jennsays 10% of all fridgescould be reused, butthe new system makesthis business no longereconomical. However,Ozone Friends hasdeveloped a new busi-ness hauling fridges tostorage areas or recy-clers (retailers no

longer pick up old fridges in exchange fornew, and local authorities generally do notaccept commercial waste). The group mayexpand into offering to remove the refriger-ant and cut the fridges into easily trans-portable pieces. –W. Conard HoltonC

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Rice Code CrackedReports of the completion of the genomesequences of one of the world’s most importantfood sources—rice—were published in the 5April 2002 issue of Science. The two most widelygrown varieties were sequenced. A group of U.S.and Chinese scientists, including scholars fromthe Beijing Genomics Institute (anew major genome sequencingcenter in China whose workwas partially funded by theNIEHS), sequenced the indicavariety, while researchersfrom Sygenta, a biotechnol-ogy/agribusiness company,sequenced the japonica variety. Inan editorial accompanying the reports, Scienceeditor-in-chief Donald Kennedy notes that thiswork may not only help improve the crop yieldsand nutritional value of rice for the millions whodepend on it as a food source, but will also serveas a stepping stone to decoding the similar butlarger genome sequences of other importantcereal grains.

Canada Restricts CarsIn 2002 the Canadian government announcednew stricter emissions standards for on-roadvehicles targeted at reducing levels of smog-forming pollutants (such as particulate matter,volatile organic compounds, and carbon monox-ide) and toxic substances (such as benzene andacrolein). Cars and trucks are the largest sourceof greenhouse gases in Canada, contributing25% of such emissions, a level that is onlyexpected to increase in the future.

Included in the proposedmeasures are technicalstandards for exhaust,evaporative, and crank-case emissions, onboarddiagnostic systems, andother vehicle emissioncontrol systems. The measureshave been developed to mirror U.S.EPA regulations for the same systems in line withefforts of create an integrated vehicle manufac-turing market in North America.

The Origin of RainA new NASA computer model can trace precipi-tation back to the place on Earth from which itoriginally evaporated, possibly helping scientistsimprove rainfall and drought forecasts. Projectleader Mike Bosilovich says the model providesa much clearer picture than ever before of howwater vapor travels through the atmosphere,and is the only tool available that can deter-mine individual regional atmospheric moisturesources and account for all the variables requiredfor source analysis. This can help scientists gaina clearer picture of climate change by helpingthem understand annual fluctuations in geo-graphic sources of atmospheric moisture. Thenext step is to plug more observational data intothe model; currently all variables are simulatedexcept sea surface temperature.

Out in the cold. A new U.K. rule requires recy-cling of fridges, but a lack of recyclers has ledsome people to just dump outdated chillers.

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A 392 VOLUME 110 | NUMBER 7 | July 2002 • Environmental Health Perspectives

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Save Your Hide fromUV DamageDespite the increasing number of sunscreen products on store shelves,the incidence of skin cancer continues to climb. The American CancerSociety says the rate of melanoma, the deadliest type of skin cancer,more than tripled in Caucasians between 1980 and 2002. However,two recent studies have found that properly treating clothing andadding stable antioxidants to sunscreen can reduce skin damage fromultraviolet (UV) exposure.

Although experts recommend covering up in sleeves and pants toblock UV rays, just how protective is clothing? In a study published inthe May 2001 issue of the Journal of the American Academy ofDermatology, researchers at the New York University School ofMedicine measured the UV rays that pass through different T-shirt fab-rics. White T-shirt fabric was washed and dried five times under homelaundry conditions. Some samples were then dyed yellow or blue withliquid fabric dye or treated with Tinosorb, a commercial UV absorber

added to the wash cycle. The researchers then calculated UV protectionfactors (UPFs), analogous to sun protection factors, or SPFs.

Before any treatment, white T-shirts had a UPF of about 5. Afterfive launderings, UV protection improved by 50% due to fabricshrinkage. Tinosorb boosted UV protection by 407% (to a UPF of23.4), yellow dye by 212% (UPF 16.5), and blue dye by 544% (UPF33.25). This shows that clothing can be treated inexpensively to blockUV rays. Tinosorb is the active ingredient in the laundry additive SunGuard, says research team member David Polsky. One box of SunGuard costs $2–3, and protection lasts several months.

But no sunscreen totally blocks UV light. The small amount ofUV light that leaks through penetrates skin, creating free radicals thatdamage DNA and depress the immune system. To investigate wherefree radical damage occurs, biophysicist Kerry Hanson of theLaboratory for Fluorescence Dynamics at the University of Illinois atUrbana-Champaign peered into different depths of skin with a two-photon laser fluorescence imaging microscope. This type ofmicroscopy shows cellular details down to the submicron level with-out damage to living cells. She and her colleagues are the first to usetwo-photon microscopy to measure UV-induced free radical genera-tion in living skin.

RADIATION

If a Tree Falls inthe CityTrees in urban settings have often beenthought of as little more than decorativeobjects ripe for sacrifice in the name of devel-opment. But in addition to making city lifemore pleasant, trees also offer significanthealth and environmental bene-fits, trapping and converting airpollutants as well as catchingand controlling stormwaterrunoff. To provide city plannersand officials with solid evidenceof the value of city foliage, theWashington, D.C.–based non-profit organization AmericanForests has quantified the eco-nomic worth of trees to citiesand towns.

Using satellite and aerialimagery and other data,researchers at American Forestshave determined the amount oftree canopy cover for almost 20cities and towns so far. Usingthe organization’s own geographic informa-tion system–based software, they then cal-culated the amount of air pollutionremoved by urban forests and the lost ben-efits urban forests would have provided hadthey been left standing. They also calculat-ed the effect of trees on stormwater runoff.

Overall, urban tree canopy cover hasdeclined by 30% over the past three decades,says Cheryl Kollin, director of the UrbanForest Center at American Forests, andcanopy tree cover has decreased in most ofthe surveyed areas. In Washington, D.C., for

example, densely forested areas—those withat least 50% tree cover—decreased from37.4% of the city’s land to 13.4% over theperiod 1973–1997, while sparsely forestedareas—those with less than 20% tree cover—increased from 51% to 71.8%. The result,according to American Forests, is a 34%increase in stormwater runoff. The lost treesalso would have removed an estimated354,000 pounds of air pollutants, includingsulfur dioxide, carbon monoxide, nitrogen

dioxide, ozone, and particulate matter of 10microns or less.

Pollutant gases diffuse into leaves throughthe stomata and react in a variety of ways,converting into other compounds that some-times actually benefit the tree. The effective-ness of trees at removing air pollution varieswith the type of pollutant and the type oftree, says David Nowak, project leader of theU.S. Forest Service’s urban forest ecosystemresearch unit in Syracuse, New York.

Trees mitigate solids pollution by filteringparticles from the air, Nowak explains. “Trees

that have sticky and hairy leaves or smallerleaf surfaces or smaller leaves tend to be bet-ter filters,” he says. But unlike gaseous pollu-tants, particulates aren’t converted orabsorbed. An average of 50% of particlesblow off the tree and back into the atmos-phere. Most of the rest either fall to theground when the tree sheds its leaves or arewashed off by rain. “The soil is the ultimateresting place for a lot of these particles,”Nowak says. The Forest Service is currently

investigating whether these parti-cles actually do less harm in the soilthan in the air.

The increased costs to taxpay-ers as a result of the shrinking treecanopy are significant. InWashington, D.C., alone, process-ing the additional stormwaterrunoff costs about $226 million peryear, and the additional air pollu-tion abatement expenses add anoth-er $1 million annually, according toAmerican Forests. “The economicvalue placed on air pollutants isestablished by state public servicecommissions from costs to societynot reflected in the marketplace,such as rising health care costs

from respiratory illnesses,” Kollin says. Andtrees provide still other concrete benefits tourban dwellers, such as providing shade thatcan reduce residential cooling costs.

Everybody likes trees, but many citydwellers and city managers don’t realize justhow valuable they are. But according toKollin, the average urban area still has abouta 30% tree canopy cover. She says, “AmericanForests believes that cities could increase theirtree canopy cover by at least ten percent andreap increased environmental benefits.”–Scott Fields

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Environmental Health Perspectives • VOLUME 110 | NUMBER 7 | July 2002A 393

The Power to HarmA report presented in April 2002 by formerEPA regulatory affairs director Eric Schaefferimplicates air pollution produced by coal-burning power plants in an estimated 5,900deaths, 14,000 cases of acute bronchitis,and 140,000 asthma attacksyearly. Schaeffer resignedhis post in March in protestof what he calls “a WhiteHouse that seems deter-mined to weaken therules [the EPA is] tryingto enforce.”

Eight utilities namedin the report were all charged in 1999 withviolations of an EPA regulation under theClean Air Act that establishes the extent towhich aging coal-fired power plants can beenlarged or upgraded before investments aremade for pollution control devices. The utilityindustry has countered that no generallyaccepted models exist that can produce thekind of causation implied in the study.

Zero-Sulfur FuturePenn State University researchers have devel-oped a new fuel desulfurization process thatuses lower temperatures than current methodsand does not require reactive gases. The processyields the ultraclean, zero-sulfur compoundsneeded for fuel cells as well as fuels that willmeet the new stricter U.S. fuel sulfur standardsslated to take effect in 2006.

The process uses metals or metal alloys to“grab” only the sulfur, leaving behind thedesirable fuel components. The metals canclean 10 times their volume of fuel beforebecoming saturated with sulfur, whereuponthey are regenerated with solvents. Theresearchers envision the process being usedin special clean fuel pumps and in fuel cellvehicles themselves.

A Financial Plan forthe EnvironmentThe European Environmental Bureau (EEB), afederation of 133 environmental organizations,has launched a campaign for environmentalfiscal reform consisting of environmental tax-ation reform, the removal of subsidies thatnegatively affect the environment,and the development of fiscal incen-tives for environmentalprotection. The EEB planwill also address anysocietal impacts result-ing from the higherenergy prices theypropose. Germanresearchers estimatethat implementingenvironmental fiscalreform could createup to 250,000 new jobs in Germanyalone over the next eight years.

Sixteen years after discovering penicillin, Alexander Fleming predicted in a 1945New York Times interview that the misuse of antibiotics could lead to the evolu-tion of drug-resistant bacteria. As early as the late 1940s, when antibiotics wereavailable to the public without prescription, hospitals began reporting evidence ofdrug-resistant strains. Agricultural use of antibiotics surged forward in the UnitedStates when, in 1951, the U.S. Food and Drug Administration (FDA) approved theiruse as feed additives for farm animals to control disease and promote growth.Antibiotics are also used to control crop diseases.

As the antibiotic market grows—by some estimates to over $24.5 billion by2006—so do concerns over the evolution of drug-resistant bacteria. As part of its

health and food safety advocacyefforts, the Washington, DC–basedCenter for Science in the Public Interest

(CSPI) has developed a website, located at http://www.cspinet.org/ar/, highlight-ing the work of its Antibiotic Resistance Project. The project serves as a way to edu-cate public and private institutions, as well as the general public, on why policies andpractices should be changed to prevent further increases in antibiotic resistance.

Browsing through the site, consumers can find guidelines for using antibioticsresponsibly through the Consumer Tips for Using Antibiotics link. Links to infor-mation on proposed antibiotic-related federal legislation and the CSPI’s regulatoryactivities, such as their petitions to the FDA on banning the use of human antibi-otics for livestock growth promotion, are available under the Legislative andRegulatory Update header. The homepage also includes a request for stories frompeople who have become sick from antibiotic-resistant bacteria. Still another linkon the homepage takes visitors to the site of the Keep Antibiotics Working cam-paign, a project of the CSPI and several other environmental, agricultural, andadvocacy groups.

The Antibiotics in Jeopardy page features an in-depth interview with projectdirector Tamar Barlam that discusses in lay terms topics including the hows andwhys of antibiotic-resistant bacteria and how food can spread such bacteria. Thesetopics are further addressed in the 1998 CSPI report Protecting the Crown Jewelsof Medicine. The report outlines the CSPI’s proposals for government and healthcare provider actions that the group believes could reduce the spread of antibiot-ic resistance and lead to better overall management of antibiotics. The report alsoincludes a section on the economic effects of antibiotic resistance and a listing of10 common antibiotic-resistant bacteria, along with the diseases they cause andthe drugs they are resistant to. –Erin E. Dooley

Center for Science in thePublic Interest Antibiotic

Resistance Project

Hanson exposed skin to UV rays equiva-lent to two hours of North American middaysun in July. She measured free radical forma-tion before and after UV exposure with a flu-orescent probe that glows when it reacts withfree radicals. Hanson found that UV lightgenerates tremendous numbers of free radi-cals in skin in all layers of the epidermis. Butcompared to bare skin, an SPF-15 sunscreenreduces free radical formation in the lowerepidermis, where DNA resides, by 90%.Adding the antioxidants vitamin E acetateand a stable form of vitamin C called sodiumascorbyl phosphate to sunscreen reduces freeradical formation by 95.5%. This researchwill appear in an upcoming issue ofPhotochemistry and Photobiology.

Ascorbic acid, the common form of vita-min C found in vitamin supplements andorange juice, degrades rapidly when light hitsit, says Hanson. In contrast, sodium ascorbyl

phosphate remains completely stable in sunand heat, she says, as does vitamin E acetate.Enzymes in the skin convert the vitamins toactive forms that accumulate in skin andchange free radicals into nondestructive mol-ecules. Hanson advises checking a sunscreen’singredient list to make sure these stable formsof vitamins C and E are there.

Hanson’s research “involves some inter-esting new techniques,” says Wayne Wamer,a research chemist at the U.S. Food and DrugAdministration Center for Food Safety andApplied Nutrition in College Park, Mary-land. However, the connection between UV-induced free radicals and skin cancer remainscontroversial. Wamer says future studies needto evaluate whether the observed reductionof free radicals by antioxidants has biologicalsignificance, such as a reduction in cell toxic-ity, carcinogenesis, or aging effects.–Carol Potera

The Beat