Hospitals can reduce their emis-sions of particulate matter (PM) by80% and heavy metals by at least50% if they adopt rigorous segrega-tion practices, according to researchpublished in the July 15 issue ofES&T (pp 3152–3157). The findingsalso raise questions about the datathat both the European Environ-mental Agency (EEA) and the U.S.EPA compile to comply with theConvention on Long-Range Trans-boundary Air Pollution (LRTAP).

Hospitals are required to segre-gate hazardous medical wastes be-cause of the biological risks thesematerials pose. But how hospitalsdeal with these materials, as well asnonhazardous wastes, varies con-siderably from country to country.In the United States, medical wasteis segregated using three categories:“pathological”, which includes

human organs and bodily fluids;“red bag”, which covers infectiouswastes; and “general trash”. EEAdistinguishes only between “specif-ic hospital waste” and “other hospi-tal waste”; Portugal, on the otherhand, defines four groups of med-ical waste.

These differing classificationsof medical waste in signatorycountries prevent the accuratecomparison of the compositionof incinerated medical wastes atan international level, says MariaConceição Alvim-Ferraz, assistantprofessor at the University ofPorto’s Laboratory of Process, Envi-ronment and Energy Engineeringin Portugal and first author of theES&T study. This is important be-cause the LRTAP Convention re-quires countries to report emissionfactors, which are calculated as ra-

tios between emission rate andwaste feed rate. “Published emis-sion factors, such as those givenby EEA or EPA, are provided as gen-eral defaults to inventory compil-ers, where no national data isavailable,” says Haydn Jones ofAEA Technology Environmentin Culham, Oxfordshire, UnitedKingdom, who is responsible for

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Environmental▼Newsdition called droopwing, in whichlead affects the chicks’ peripheralnerves, making them unable to fly,says Finkelstein. “Every one of thechicks that I sampled around thebuildings that had droopwing hadvery high lead levels,” she adds.Blood lead levels in the droopwingchicks averaged 440 micrograms perdeciliter (µg/dL), while the levels innon-droopwing chicks near thebuilding sites averaged 85 µg/dL andlevels in chicks at a reference sitemore than 100 meters from anybuildings averaged 6.0 µg/dL.

To confirm that the lead poison-ing is indeed being caused by lead-based paint and not other sources,such as spent lead shot, Finkelsteinand her colleagues used a tech-nique called lead isotopic finger-printing, in which four naturallyoccurring isotopes of lead—204Pb,206Pb, 207Pb, and 208Pb—are mea-sured. Because the natural abun-dances of these four isotopes varybetween different sources of lead,the analysis can be used to identifysources and pathways of exposure.

The researchers analyzed paintchips from the chicks’ nests locatednear the building sites and com-

pared the lead isotopes with thosefound in the chicks’ blood. Sureenough, the isotopic analyses indi-cated that lead-based paint was thesource of lead exposure.

Surprisingly, the soil in the nestsdid not contain elevated levels oflead, except when the nests werevisibly contaminated with paintchips, says Finkelstein. The resultsindicate that the chicks are beingexposed primarily through inges-tion of paint chips rather than fromcontaminated soil.

The results are important for fu-ture lead cleanup efforts on Midwayand elsewhere. USFW does havesome money allocated this year fordetermining the extent of the leadproblem on Midway, according toLee Ann Woodward, an ecotoxicolo-gist with USFW’s Pacific IslandsOffice in Honolulu, Hawaii.“Essentially, we are going to try todetermine how much soil is conta-minated with lead,” says Woodward.“Then next year, we will probably re-move the soil, or in some areas, if itis possible, cover it up,” she says.The problem is that Midway hasmany burrowing birds, which willjust stir up the soil again. “So we will

probably be doing large-scale re-moval,” she adds. It is unclear howmuch the removal process will cost,and that is one of the questionsUSFW is currently trying to answer.

Before the Department ofDefense turned Midway over to theDepartment of the Interior to bemanaged by USFW in 1997, the Navydid millions of dollars of remedia-tion, says Woodward. “There was somuch petroleum in the groundwaterthat they pumped it out for over ayear.” As for the lead, she says, “theytried sandblasting the buildings, andone plan was to just seal it on thebuildings.” Since then, there hasbeen further deterioration of thepaint on the buildings. “Essentially,the lead cleanup is going to have tobe assessed and redone,” she says.

Other decommissioned militarybases are facing similar problems.Johnston Island, for example, whichis located in the North PacificOcean southwest of Hawaii, hasseveral buildings with lead-basedpaint, says Finkelstein. “It is diffi-cult to get rid of.” The island is ex-pected to be transferred to USFW in2004 and become a wildlife refugeas well. —BRITT E. ERICKSON

Study questions medical incineration emissions data

How hospitals handle medical wastemakes a significant contribution to theirnations’ air pollution emissions.

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the compiled emission factorsin EEA’s Emission InventoryGuidebook.

However, Alvim-Ferraz arguesthat politicians should make an ef-fort to standardize categories andthat “there should be a unified clas-sification to allow comparisons ofemission factors.” Furthermore, be-cause EEA’s and EPA’s compilationslack information on the composi-tion of incinerated medical waste,“it is not safe to use these emissionfactors,” she says.

To quantify how different hospi-tal waste separation practices affectthe incinerator emissions, Alvim-Ferraz and her co-worker, SérgioAfonso, measured the concentra-tions of PM, arsenic, cadmium,chromium, lead, manganese, mer-cury, and nickel from the controlled-air incinerator of a 300-bed hospitalin Portugal. The usual waste treat-ment practice at this and other hos-pitals in Portugal is to burn what aredefined as group III and group IVwastes, which are similar to theUnited States’ red bag and patholog-ical classifications, respectively.However, Portuguese legislation re-quires only that group IV waste beincinerated at the hospital. Group IIIwastes need to be sterilized, butthen afterwards can be dumped intothe normal municipal garbage.

The hospital set up a program toencourage workers to segregate the

waste more rigorously, which didnot change the total daily wasteproduction rate of 3.9 kilograms perbed per day but decreased group IVwastes by 80%—from 400 to 80grams per bed per day—while in-creasing group III wastes. Subse-quent burning of exclusively groupIV waste led to a dramatic decline ofPM and heavy metal emissionsfrom the hospital’s incinerator. Thegroup III waste was sterilized andburned in a municipal waste incin-eration plant. The researchers saythat the increase in group III wasteburning did not counterbalance thedrop in emissions from the hospitalincinerator, because many munici-pal waste incinerators are equippedwith modern air pollution controldevices. The vast majority of incin-erators operating at hospitals, how-ever, are not similarly equipped.

Nevertheless, Alvim-Ferraz andAfonso found that even the reducedemissions emanating from the in-cineration of rigorously segregatedgroup IV waste surpassed the legalemission limits by 1.3-fold for mer-cury, 20-fold for PM, and 90-fold fordioxins, underlining the need toequip medical waste incinerators athospitals with air pollution controldevices. Adds Alvim-Ferraz, “Appro-priate equipment to control atmos-pheric pollution must be used toprotect human health.” —ORI SCHIPPER

Membrane-based treatmentprocesses appear to be promisingtechnologies for removing en-docrine disrupters from municipalwaste landfill leachate, according toresearch in this issue of ES&T (pp3430–3434). Although the technolo-gies can remove large amounts ofthe hormone-mimicking chemicalsfrom sewage effluents, their ratherhigh cost has prevented widespreaduse by wastewater treatment plants(WWTPs). Landfill leachate vol-umes are low, however, comparedwith WWTP effluents, making ad-vanced treatment processes moreeconomical for landfill leachate.

Although the estrogenic activity ofuntreated landfill leachate is withinthe range of WWTP influents, littleattention has been paid to removingendocrine disrupters from municipallandfill leachate, presumably becausemany landfills contain a plastic bot-tom sealing to prevent leachate fromcoming into contact with the envi-ronment. Such barriers, however,typically begin to leak after about 12years, according to Peter Behnisch,division leader of Life Sciences at SGSGermany, who has tested the estro-genic potency of landfill leachatein Japan and Germany. In addition,many older landfills do not even have

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Reacting to reactivechemicalsThe Occupational Safety and HealthAdministration (OSHA) needs tostrengthen its regulation of reactivechemicals to prevent fires, explo-sions, and toxic releases, accordingto a petition by eight internationalunions and the American Federationof Labor–Congress of IndustrialOrganizations (AFL–CIO). Althoughthe unions have been making simi-lar petitions since 1995, their casewas strengthened by a report re-leased by the U.S. Chemical SafetyBoard (CSB) in September 2002,which called reactive chemical inci-dents a “significant chemical safetyproblem” that can cause major en-vironmental damage. For more in-formation, go to www.paceunion.org.

Farmers violating GMcrop requirementsA significant number of farmers arenot complying with U.S. EPA re-quirements for growing geneticallymodified (GM) crops, according to areport by the Center for Science inthe Public Interest (CSPI). If farmersgrow GM corn that contains Bttoxin, they must plant 20%of their acreage with non-Bt corn to prevent pesticideresistance. The reportpoints to U.S. Departmentof Agriculture data showingthat in 2002, 19% of all Bt corn farmsin Iowa, Minnesota, and Nebraskawere in violation of this “refuge” re-quirement, and 13% of them had norefuge whatsoever. CSPI believesthe percentage of farmers in viola-tion is higher than the biotechnologyindustry claims because small farmsare typically not surveyed. CSPI rec-ommends that EPA require biotechcompanies to make on-farm inspec-tions and farmers to provide mapsand seed-purchase records to thebiotech companies. A copy of thereport, Planting Trouble, is availableat www.cspinet.org.

News Briefs

Removing endocrine disrupters from municipallandfill leachate

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