lead contamination on local, regional, and global scales, said Flegal. "The guys from Columbia did not use that methodology, which is remarkable," he said. Flegal noted that the researchers misinterpreted the contribution of lead from road runoff. "The drainage area of the lake is 10 times greater than the surface area of the lake. To suggest that surface runoff is an inconsequential source of die lead, widiout rigorous corroborating measurements, is not consistent with any geochemical model mat I am aware of." David Sussman, a consultant for incinerator producer Ogden Projects, also found fault with the paper's suggestion that leaded gas is not the major contributor to urban lead concentrations. "Every study that I have found diat took core samples around waste to energy plants, ash landfills, and highways showed the exact opposite," said Sussman. "Waste combustion has been attributed for about every malady or environmental problem in the world at least once." Today EPA reports that atmospheric lead from solid waste incineration falls below 1% said Sussman "Of all the data I've seen, for even badly operated incinerator technology, while they can offer some lead to the environment, they are certainly a relatively small source," added Ellen Silbergeld, director of the program in Human Health and Environment at the University of Maryland. Which is not to say that environmental lead is no longer a concern, said Silbergeld. "The most recent report on the Third National Health and Nutrition Survey shows that die average blood lead concentration (2.3 mg/dL) is still about two orders above my calculation of the natural level (0.02mg/dL), and there are still no thresholds for lead toxicity established," added Flegal. "That that lead still is a major environmental concern, and all the m&ior sources of lead contamination need to be carefully quantified as the National Research Council recommended in 1993 "–CATHERINE M. COONEY
Research priorities for fueling fuel cells called into question As automakers race to deliver commercially available fuel-cellpowered cars by 2004, researchers around the globe are grappling with how to supply fuel to the cells. At this year's annual meeting of the Transportation Research Board, researchers charged that both car manufacturers and the federal government are neglecting the best option for providing hydrogen fuel. "The paramount issue that is facing fuel cells right now is how you get the hydrogen fuel to the vehicle," stated Jason Mark, senior transportation analyst for the Union of Concerned Scientists' Transportation Policy Program in an interview. The fuel issue has only taken center stage now because of the advanced stage of development attained by the underlying fuel-cell technology Spurred by the 2004 deadline set by the Partnership for a New Generation of Vehicles (PNGV1 a program initiated in 1993 bv the Clinton Administration in tandem with the "big
three" U.S. automakers and a number of federal agencies, proton exchange membrane (PEM) technology emerged as the optimal solution for powering fuel cell-powered cars. They sit inside all of the concept cars unveiled to date, according to Bernadette Geyer, assistant executive director for Fuel Cells 2000, a nonprofit organization. The majority of current fuelcell fuel research in both the public and private sector is geared toward synthesizing hydrogen inside automotive engines from either gasoline or methanol through a process known as reforming. Given that all concerned are striving to keep the resulting fuel cell cars' sticker prices as low as possible, there should be more active research into a third option, the "direct" method tiiat relies on hydrogen generated elsewhere to fill a fuel tank, claimed C. E. "Sandy" Thomas, vice president of energy and environment for Directed Technologies Inc (DTI) of Arlington Va At the Transportation
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Research Board meeting, Thomas presented research conducted for the Department of Energy (DOE), which showed that direct hydrogen fuel would be the least expensive option to implement, taking into account the cost of building the necessary infrastructure to supply hydrogen. The cost procedures used in the study were recognized by the National Research Council, Thomas said. It would be easier to create an automobile based on direct hydrogen technology by 2004 than it would be to develop the technologies to create hydrogen from methanol and gasoline, said Christopher Borroni-Bird, senior manager of technical strategy planning for DaimlerChrysler, in an interview. He said his company has determined that the technology for converting gasoline will not be ready in time for the 2004 deadline and that "another eight or nine years of develODment are probably needed" but methanol still has a "fighting chance" "Clearly, [direct] hydrogen is the most elegant solution," Bor-
roni-Bird continued, emphasizing that DaimlerChrysler already uses direct hydrogen in its fuelcell buses. "If hydrogen was widely available, the fuel cell would be much easier to commercialize," he added. Though he had not read DTI's paper on the costs of implementing hydrogen as a fuel, he said, "The costs may be the least, but in terms of the dislocation to the infrastructure, it's probably the most severe." Concerns about disrupting the auto-fueling infrastructure helped convince DaimlerChrysler to direct its primflrv focus on de~ veloping methanol 3. fuel ttlclt Borroni-Bird said would demand less extensive infrastructure changes Borroni-Bird stressed that it is crucial to get oil company support for any distributed fuel option. Asking an oil company "to provide a completely new fuel is not a very easy task," he said. He also pointed out that some oil companies, notably Shell Oil, are studying hydrogen and the infrastructure it would require. "I don't think any of them are pushing for a hydrogen infrastructure," he added.
The NECAR III is a prototype fuel-cell-powered car from Mercedes-Benz that uses methanol as fuel. A reformer system located in the rear of the vehicle converts the liquid fuel into hydrogen through water-vapor reformation. (Courtesy DaimlerChrysler) 1 0 8 A • MARCH 1, 1999/ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS
Until recently, Ford Motor Company was the only major automaker pursuing direct hydrogen technology for use in light-duty vehicles, according to DTI. The prototype Ford P2000 sedan unveiled at this year's North American International Auto Show in Detroit was built around the direct design. However, after teaming up with DaimlerChrysler and Ballard to jointly develop fuelcell technology last December, Ford began following a "fuel neutral" approach toward developing a fuel-cell vehicle according spokeperson The DTI claim that building a hydrogen infrastructure would cost less, per vehicle, than that required to support either methanol or gasoline contradicts conventional wisdom. People often assume that a nationwide pipeline must be constructed to shuttle hydrogen around the continent, Thomas explained. That is not true, he said, noting that natural gas from existing pipelines could be used ss 3. source for producing hydrogen. It would also be possible to synthesize hydrogen locally at fueling stations using small-scale steam methane reformers or electrolyzers he said There's an overblown fear of both nationwide and regionally of building a hydrogen infrastructure Mark agreed While acknowledging the virtues of the direct hydrogen method, Patrick Davis, program manager for DOE's Office of Advanced Automotive Technology, said "with our limited budget, we can't afford to develop a hydrogen infrastructure in the U.S." The majority of DOE's funding for fuel-cell fuels research is bankrolling efforts to create a technology called a partial oxidation (POX) processor for creating hydrogen from gasoline Davis said. This re~ search—which supports the PNGV efforts to create with very high fuel economy by 2004 js investigating the same technology that DaimlerChrysler scientists say will not be ready by that year
Thomas and Mark question this DOE strategy. To support fuel cells, the existing gasoline infrastructure could require alterations, Thomas said, explaining that the cells may require a special, low-sulfur grade of gasoline. That could require a "lot of investment" at gas stations, including new pumps and new tanks, he said. Borroni-Bird acknowledged that DaimlerChrysler is using California's reduced Slllflir 23.S formulation as the fuel for its POX "Cramming gasoline into a fuel cell vehicle compromises its true environmental promise," charged Mark, who called methanol the second best option. While all of the fuel-cell vehicle fueling options would emit dra-
matically less pollution, only a vehicle powered directly by hydrogen would be a true zeroemissions vehicle. The direct hydrogen fuel-cell method would also result in lower greenhouse gas emissions, according to research by Mark Delucchi, a research scientist at the University of California at Davis's Institute of Transportation Studies. Also, gasoline would produce higher emissions than either direct hydrogen or methanol, according to DTI research. For all its potential virtues, hydrogen is hobbled by public perception, which is still colored by the Hindenburg explosion. "Hydrogen has a bad rap—it's much safer than people think," BorroniBird said. "A compressed hydro-
gen tank on board a vehicle would be far safer than anything available today, particularly gasoline tanks," Thomas said. At least two hydrogen storage options are technically and economically feasible today, he said. "From a societal viewpoint, you're going to have to make investments" to render fuel-cell technology a viable option, summarized Thomas. "If we go down either the methanol or the gasoline route, we could be postponing the time when we get to a really sustainable energy system for the transportation sector." Borroni-Bird agreed, but stressed that "it really comes down to trying to convince the oil industry and the general customer."–KELLYN S. BETTS
New test advances understanding of fish-killing algae Although scientists are far from understanding what drives blooms of the toxic alga Pfi.esteria piscicida, major breakthroughs have been made in detecting the dinoflagellate at fish kills. A new test promises to speed decisions to close waters where Pflesteria has bloomed, said state officials. Parke Rublee, biology professor at the University of North Carolina, announced at an EPA conference in January that his new genetic probe "verifies the suspicion that Pflesteria is widespread in estuaries along the East Coast." Despite the probe's inability to distinguish between toxic and nontoxic forms of the alga, its development "will save time and money and help protect public health," said Liz Kalinowski, spokesperson for the Maryland Department of Natural Resources (DNR). Because the test is inexpensive and fast state officials can now respond more quickly to outbreaks by closing off access to affected water she explained Discovered in 1991 by Joann Burkholder, a botany professor at North Carolina State University, Pflesteria is an ambush predator that has killed billions of fish and sickened people in outbreaks in North Carolina and Maryland
Mistaken identity? Open, bleeding sores on menhaden could be caused by either a fungus or Pfiesteria. (Courtesy Vicki Blazer, U.S. Geological Survey)
{ES&T, ,198, 32(1), 26A-30A). It has a complex lifecycle with 24 different forms, most of them nontoxic. It can react swiftly to dense populations of fish, typically menhaden, by changing its form and releasing a toxin that creates bleeding lesions, disorientation, and death. Because of its complexity and ability to rapidly revert to a nontoxic form, monitoring and identification of Pflesteria in the field has been cumbersome and expensive, Rublee said. Electron microscopy and fish toxicity tests to detect Pflesteria in water samples can take as long as four weeks and cost $1500, he said. Rublee's new test for the alga costs $25 and requires two days
to process. Known as a polymerase chain reaction (PCR), it utilizes a primer—a short piece of DNA unique to Pflesteria piscicida. When exposed to complementary fragments of Pflesteria DNA from a water sample, the primer manufactures millions of copies of a protein that researchers can identify with gel electrophoresis, a common method for identifying DNA and protein molecules. In late July,tinePCR probe verified the presence of Pflesteria in the Neuse River at the only fish kill of the summer. Rublee's lab also found Pflesteria in samples of coastal water from Delaware to Georgia. Rublee emphasized that "the probes confirm whether Pflesteria is present or not, but can't determine if it is in a toxic or nontoxic form." He concluded that "the probe won't be really effective until it can be used with a probe for the toxin." The state of Maryland will be using Rublee's probes in monitoring efforts this summer, Kalinowski said. But the state will continue to rely on the presence of fish lesions as an indicator of toxic Pflesteria, despite new studies concluding that such lesions may have other causes.
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