Fluoroquinolones’ fate measured in waste and natural waters lead to antibiotic-resistant bacteria. The U.S. Food and Drug Administration’s Center for Veterinary Medicine has proposed banning enrofloxacin, one of the major FQs in the United States, for use in poultry farming because of evidence that shows it contributes to the development of FQ-resistant Campylobacter infections in humans. And in a 2001 discussion paper, the European Agency for the Evaluation of Medicinal Products proposed that an environmental risk assessment be required for human medicinal products that have predicted concentrations in surface water greater than 0.01 micrograms per liter. Golet and colleagues analyzed raw sewage, treated wastewater effluents, and river water samples at multiple locations in the densely populated Glatt River watershed bordering Zürich for ciprofloxacin and norfloxacin, Rhine the most widely conGlattfelden 3 sumed FQs in Switzer(33.2 km) Rheinsfelden land. Concentrations (35.2 km) of each antibiotic in raw sewage ranged from Bülach (25.4 km) Niederglatt (22.3 km) 255 to 568 nanograms per liter, but dropped by 80% during wastewater treatment because of Rümlang 2 Kloten-Optikon (13.2 km) (12.0 km) strong sorption of FQs to Bassersdorf sewage sludge. The mass Zurich-Glatt Dübendorf (6.3 km) balances show that an(9.8 km.) other 48–66% of the reFallanden maining FQs were not (1.4 km.) 1 N traceable in the river Greifensee outlet (1.2 km) waters downstream of treatment facilities where the waters enter Fluoroquinolones were detected in decreasing concenthe River Rhine, as a trations in raw sewage, treated wastewater effluents, result of sediment deand river water near Zürich, Switzerland. The dots and position or possibly their diameters indicate municipal wastewater treatment photolysis. plants and the amount of effluent discharge, respectively. The Swiss study River sampling stations are marked as 1–3; downstream could well serve as a distances from the Greifensee are listed in parentheses. ENVIRON. SCI. TECHNOL.
A detailed account of the mass flows of fluoroquinolone antibacterial agents (FQs) in a Swiss watershed (Environ. Sci. Technol. 2002, 36, 3645−3651) shows they are found at very low concentrations in natural waters. The study, conducted by Eva Golet, Alfredo Alder, and Walter Giger from the Swiss Federal Institute of Environmental Science and Technology, finds that a large fraction of the FQs entering wastewater plants is removed during treatment, with the remaining FQs in the effluent further reduced as they flow downstream. However, questions remain about the dangers of FQs in biosolids and soil. FQs represent a very potent class of human and veterinary antibiotics that are often used as the second line of defense when other treatments fail, but concern is growing that frequent use could
Government Watch EU plan for GMOs
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The European Parliament has approved stringent new rules on the tracing and labeling of genetically modified organisms (GMOs) in food. If approved by the Environment Council later next year, the rules would replace the current moratorium on GMO approvals in the European Union (EU). Parliament agreed that labeling should be required for all food and animal feed containing genetic material above a threshold of 0.5%. Last summer, the European Commission proposed a 1% threshold. Parliament also voted to label all refined products that are derived from GMOs even if no GMO traces are detectable. A further rule would ban shipments into the EU of food and feed containing accidental traces of GMOs not authorized in the EU. Simon Barber of EuropaBio, a European biotechnology industry association, called the 0.5% threshold “unrealistic”, while a spokesperson for the confederation of EU food and drink industries called the requirements impossible to implement, adding they would seriously undermine the competitiveness of European companies. The EU environment ministers will now decide whether to incorporate the Parliament’s amendments, probably at their meeting in September. The ministers aren’t likely to reach a final decision before next spring, and final rules won’t be implemented until the summer of 2003, said Parliament spokesperson Ton Huyssoon. Continued on Page 341A
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Environmental ▼ News model for how fate studies of pharmaceuticals should be done, Golet says. Most other studies have relied on grab samples taken from a large area, whereas this study has focused on the fate and transport in a tightly defined region. The paper also includes a risk assessment, based on European Union guidelines, which implies the FQs pose only a low risk of toxicity in aquatic environments. However, a second part of the study, to be submitted soon, finds that FQs accumulate in sewage sludge and subsequently persist in soil after biosolids made from that sludge are applied as fertilizer, Golet says. The application of biosolids to agricultural fields has been the subject of controversy in Switzerland for sev-
eral years. Likewise, a recent report by the U.S. National Research Council on land application of biosolids strongly recommends more detailed research on pharmaceuticals in sewage sludge (see Environ. Sci. Technol., 2002, 36, 338A). “This is a truly exceptional study,” because it is the first time that a comprehensive mass balance has been determined for a pharmaceutical, says Thomas Ternes of the Institute for Water Research and Water Technology in Wiesbaden, Germany, and one of the first researchers to recognize the environmental hazard of pharmaceuticals. Further research should go toward a broader risk assessment of FQs, including looking at their effects on
soil organisms and the generation of antibiotic resistances in bacteria, which could occur at concentrations much below the toxicity level, he emphasizes. Pharmaceuticals may also cause more subtle effects, stresses Christian Daughton of EPA’s National Exposure Research Laboratory. For example, low-level exposure to multiple chemicals, anthropogenic and naturally occurring compounds, could contribute to problems such as increased incidences of human degenerative diseases. “There could be one critical point of exposure, at which homeostasis can no longer be maintained—one more chemical and everything falls apart,” he says. —ANKE SCHAEFER
SIMONETTA CORSOLINI, UNIVERSITÀ DI SIENA
Polychloronaphthalenes turn up in unexpected places
Researchers have found polychloronaphthalenes for the first time in Antarctic organisms, including penguins and migratory birds.
Research in the August 15 issue of ES&T (pp. 3490–3496) documents for the first time the presence of polychloronaphthalenes (PCNs) in animals from the Antarctic. Although these chemicals are no longer being manufactured in most countries, the findings suggest that their distribution in the environment is widespread. In addition to analyzing PCNs, Simonetta Corsolini and colleagues at Università di Siena in Italy, along with researchers at Michigan State University and the National Institute for Resources and Environment in Japan, examined the accumu340 A
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lation patterns of other persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (PCBs), and two pesticides—hexachlorobenzene and p,p´DDE—in polar animals. As expected, the researchers found higher levels of PCNs, PCDD/ Fs, and coplanar PCBs in predators, such as seals, birds, and bears, than in organisms occupying lower trophic levels in the food web, such as krill and fish, confirming that these compounds biomagnify up the food chain. In all cases, they found a good
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correlation between PCBs and PCNs, which is not too surprising because historically they were used for many of the same purposes. PCNs are similar to PCBs in terms of their structure and chemical– physical properties. They consist of a group of 75 congeners, some of which exhibit dioxin-like toxicity. In the early 1900s, PCNs were used by the wood, paper, and textile industries, but they were subsequently replaced by PCBs, which were believed to be less toxic. Despite knowledge of their toxicity, PCNs continued to be used for several decades as electrical insulators, capacitor fluids, and engine oil additives. Today, although they are no longer being produced in most countries, PCNs are ubiquitous in the environment, particularly in soils, and are showing up even in remote locations where they have never been used. Evidence reported within the past few years points to incineration and emissions from landfills as contemporary sources of PCNs. Once emitted into the atmosphere, PCNs, like many other POPs, can be transported in air to the polar regions, where they become entrapped in ice. When the ice melts, the compounds are released back
their contribution to the dioxin toxicity,” he adds. Of all of the organisms, the researchers found the highest levels of dioxin-like chemicals in the South polar skua, presumably because these Antarctic birds migrate north to more polluted areas during the winter. “A profile of pollution in an area will likely be reflected in an organism’s tissues,” serving as a fingerprint of that particular ecosystem, Corsolini says. The findings suggest that POP detection can be used to trace migration behavior in animals. “This has already been reported for birds that migrate from Africa to Europe, where different POPs are detected in the environment,” Corsolini adds. Although the PCN congeners found in the Antarctic organisms were relatively low in toxicity, the research is important in that it confirms that PCNs are a global POP. “There has been an attempt to add PCNs to the POPs Treaty,” says Harner, referring to the United Nations Economic Commission for Europe (UN-ECE) POP protocol, which is somewhat different than the U.N. Environment Programme (UNEP) POP protocol. The two protocols run parallel to each other, but the UN-ECE POP protocol tends to make changes first because it targets industrialized nations, whereas the UNEP POP protocol is more general, he says. “A lot of the driving force behind the attempt to add PCNs to the POP protocol is studies like this one.” —BRITT E. ERICKSON
Novel biological process for removing perchlorate A new method that employs membrane technology and microbial chemistry could offer a cost-effective means of removing perchlorate contamination from drinking water. At an American Water Works Association (AWWA) conference in June, researchers presented results from a pilot study in which the approach reduced perchlorate concentrations to below detection levels. Perchlorate, a primary ingredient in the manufacture of rocket fuels
and fireworks, has been detected in surface and groundwater throughout the United States; exposure to the contaminant can disrupt the function of the human thyroid gland and cause developmental effects, according to the U.S. EPA. The agency released a revised draft toxicity assessment on perchlorate for public comment in June. The removal process, developed by Bruce Rittmann’s group in the Department of Civil and Environ-
Government Watch Blending water laws As part of an ongoing effort to better protect surface waters used as drinking water sources, the U.S. EPA is considering ways to integrate programs under the Clean Water Act (CWA) and Safe Drinking Water Act. Although both laws share similar objectives, the drinking water program doesn’t have the actionoriented authorities of the CWA, said EPA’s Chuck Sutfin, who spoke at an American Water Works Association conference in June. In turn, the CWA isn’t always used effectively to protect drinking water from point source and nonpoint sources of pollution, especially from farms. For example, large animal feedlots are suspected as a major source of microbial pathogens in drinking water, and conventional treatment systems at the drinking water utilities are not fully capable of removing all pathogens, Sutfin noted. To keep such pollutants from reaching waterways in the first place, EPA officials are mapping out opportunities for linking the programs where interdependencies occur, in areas such as standard setting, monitoring, and resource management, says EPA’s Karen Klima. Details are likely to be fleshed out when the agency releases its next budget request. How integration will affect states, where drinking water and clean water programs usually are under the jurisdiction of different agencies, is still unclear. Linda Eichmiller of the Association of State and Interstate Water Pollution Control Administrators says improved watershed management should also involve transportation and emergency response programs, to name a few.
PHOTODISC
into the environment, and because of their hydrophobicity, accumulate in the tissues of organisms. The higher chlorinated PCNs are generally more toxic than the lower chlorinated ones, and the most toxic PCNs have six or seven chlorines. The researchers found higher levels of the less chlorinated PCNs in Antarctic organisms than in Arctic organisms. Overall, the contribution of PCNs to the 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) toxic equivalency factor (TEF) was negligible because of the lack of the higher chlorinated congeners. TEFs are commonly used to compare the relative toxicity of an individual congener with 2,3,7,8TCDD, which is the most toxic dioxin congener. Lower chlorinated compounds are expected to predominate in the Antarctic because of a phenomenon called fractionation. “As you move away from the source region, the lighter compounds are more easily transported in the air. The heavier, higher-molecular-weight ones tend to partition onto particles and other surfaces and then drop out of the air,” says Tom Harner of the Meteorological Service of Canada, who was the first to report finding PCNs in Arctic air (Environ. Sci. Technol. 1998, 32, 3257–3265). Most of the POPs pollution originates in the northern hemisphere, in industrialized areas. “Just because of the proximity, you tend to find more of them in the Arctic than in the Antarctic,” Harner says. “In the Eastern Arctic, PCNs actually outweighed PCBs in air, in terms of
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Environmental ▼ News mental Engineering at Northwestrate levels from 60 micrograms/liter the AWWA’s Research Foundation. ern University, uses a hollow-fiber (µg/L) to below the detection limit The others include an ion-exchange membrane biofilm reactor to reof 4 µg/L, which is the current acsystem, a granular activated carbon duce perchlorate to chloride tion limit of California’s Department system, and a packed acetate bed through a natural biochemical of Health Services, says Samer bioreactor, also a biological treatprocess of electron transfer. The Adham of Montgomery Watson ment process (Environ. Sci. Technol. hollow-fiber membranes are essenHarza, the environmental engineer2001, 35, 482A–487A). tially a bundle of long, thin straws, ing firm testing the technology. A A disadvantage of the two nonbieach around 280 micrometers in divery preliminary cost estimate for ological processes is that they don’t ameter. Hydrogen gas is introduced the process comes out around actually destroy the perchlorate, inside the membranes and Adham says. They remove diffuses across the wall to perchlorate by adsorbing it where a layer of bacteria to various media, but the Hollow-fiber membrane lies in wait. The bacteria resulting concentrated Perchlorate reduction occurs in the biofilm growing on oxidize the hydrogen and brine creates difficult disthe outer of two porous polyethylene layers. reduce perchlorate in posal problems. That’s water passing along the why biological systems biofilm on the outside of look so promising, he Image unavailble for use on the membrane. notes. the Web A key feature of the sysIn the past, regulators tem is the controlled, bubhave expressed reservableless gas transfer of the tions about using biohydrogen, which eliminates logical treatments for its explosion hazard, drinking water (Environ. Rittmann says. “It’s particuSci. Technol. 1999, 33, larly advantageous because 515A). However, this systhe hydrogen diffuses tem, says Case, has an through the membrane advantage because “the wall on an on-demand hydrogen is separated by basis,” with the microbes the membrane from the themselves determining water being treated, and Source: Montgomery Watson Harza and Northwestern University. how much hydrogen moves the biofilm is on the through. Moreover, hydromembrane surface, which gen makes for an ideal electron $0.50/1000 gallons for full treatment will hopefully make it look more atdonor because it is nontoxic, doesn’t with a flow capacity of 2500 gallons tractive to regulators.” The technolpersist in water, and is by far the per minute, according to Rittmann. ogy can also simultaneously reduce least expensive bulk source of elecThe membrane process comnitrate and could remediate other trons, Rittmann adds. prises one of four technologies that water contaminants, such as broIn an ongoing pilot study of a look to be the most feasible for remate, selenate, chlorinated solcontaminated well in La Puenta, moving perchlorate from drinking vents, explosives, and metals. Calif., the reactor lowered perchlowater supplies, says Traci Case of —KRIS CHRISTEN
Prioritizing drinking water contaminants In response to recommendations from the U.S. National Research Council (NRC), the U.S. EPA is revising its approach for identifying emerging contaminants of concern. Ultimately, the course chosen will define the future of the drinking water program, said EPA’s Ephraim King at the American Water Works Association’s (AWWA) annual conference in June. As required by the 1996 Safe Drinking Water Act (SDWA) amendments, EPA published its first list of unregulated contaminants of 342 A
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concern in 1998, which is known as the Contaminant Candidate List (CCL). This CCL was pared down from an initial list of 400 contaminants to 50 chemical and 10 microbial contaminants and helped EPA prioritize its research and monitoring programs, as well as set its regulatory agenda. Because of the short timeframe for developing this first CCL, EPA had to rely primarily on expert opinion, says Tom Carpenter, an environmental protection specialist in the agency’s Office of Ground Water
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and Drinking Water. For future CCLs, which are required every five years under the SDWA, EPA is working to develop a more quantitative approach in identifying candidates that is heavily based on recommendations from an NRC report (Environ. Sci. Technol. 2002, 36, 18A). These recommendations include screening a universe of some 10,000–100,000 chemicals in commercial use, as opposed to only the few that normally receive attention. Following this initial screen, the NRC recommends determining health effects and studying occurrence for such factors as severity,
Government Watch
The U.S. EPA will decide whether or not to regulate drinking water contaminants on its CCL1 by the end of this year, before issuing the CCL2 in February. A new CCL is required every 5 years. Research and occurrence data collection for CCL1 contaminants CCL3 Feb. 2008
CCL2 Feb. 2003 2002 Regulation determinations CCL1
2004 2006 Unregulated contaminant monitoring regulation data available
2008 Regulation determinations CCL2
Research and occurrence data collection for CCL2 contaminants Source: U.S. EPA.
potency, prevalence, magnitude, persistence, and mobility to ferret out those contaminants of concern. These data would then be classified and prioritized using powerful statistical tools such as neural networks. To help develop the methodology for sorting through all these contaminants, EPA is convening an advisory working group made up of stakeholders, including public water utility representatives, environmental and public interest groups, state regulatory agencies, and public health offices. The group is expected to meet for the first time this fall, and it faces a daunting task. The amount of health effects and occurrence data on many of these contaminants is slim, as are appropriate analytical methods for detecting them at low concentrations in water, says Steve Via, a regulatory engineer with AWWA. Consequently, developing an appropriate screen will be difficult, and the working group’s efforts will likely come too late to be incorporated into the CCL2 due out in February. Carpenter acknowledges as much, but says the agency may put out an interim list using any new information gleaned through the stakeholder process before the CCL3 comes out in 2008. If data gaps are filled before the next review, EPA will move forward with a regulatory
determination, Carpenter says. For example, EPA is likely to pursue regulations for metolachlor by the end of this year and expects to make a ruling on MTBE and perchlorate as soon as it obtains the necessary occurrence data, which are expected by the end of 2003, he says. In the meantime, environmentalists worry that EPA won’t be issuing new regulations for any drinking water contaminants. “We’re concerned that they’re dropping the ball on all the contaminants already on their list by not moving forward with controls on those,” says Erik Olson, a senior attorney with the Natural Resources Defense Council. He was referring to a June 3rd Federal Register notice in which EPA announced a preliminary determination that “regulatory action is not appropriate or necessary” for nine of the contaminants on the current CCL. The data that EPA considers in its assessment include projected adverse health effects, extent of contaminant occurrence, and whether a regulation would likely result in a reduction of health risk. EPA found that it has “insufficient information to support a regulatory determination” on the other 51 contaminants, and so has not issued regulations for any of the CCL1 contaminants. —KRIS CHRISTEN
EU ban covers pesticides In July 2003, the European Commission will ban 320 active substances used in plant protection products (PPPs), including insecticides, fungicides, and herbicides, in its drive to harmonize safety standards of PPPs throughout the EU. By mid-2003, the Commission expects to have withdrawn up to 490 active substances, more than 60% of what was available in 1991. The move follows a 1991 directive to set up an EU-wide approval process for active substances in PPPs. The directive requires manufacturers to prove that their products meet required safety standards before EU authorization. Manufacturers chose not to defend these 320 substances. In June, the Commission gave industry advance warning of withdrawal of another 200 substances. It anticipates that industry won’t defend about 150, which would be withdrawn in July 2003. Companies chose not to defend substances primarily for economic reasons, including the high cost of developing a case defending the safety of the substance, says Kari Matalone of the European Crop Protection Association. Several products were already being phased out or no longer sold in Europe. However, some substances that were undefended because of limited market potential in Europe may have important markets outside the EUfor example, those used with sugarcane, tropical fruits, and tobaccoand this could lead to potential problems in international trade. By mid-July, the Commission had considered 62 defenses of active substances. It ruled that 38 of the substances have safe uses and 24 do not.
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Contaminant Candidate List (CCL) timeline
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