Environmental▼News ed from long-term physical harm or exploitation and that the studies are scientifically necessary and valid. “Human studies involving pesticides, air pollutants, or other toxicants—as opposed to therapeutic agents—are particularly controversial, and because of [these concerns] EPA should subject these studies to the highest level of scientific and ethical scrutiny,” says committee co-chair James Childress, an ethicist at the University of Virginia, Charlottesville. As an example, the committee deemed acceptable pharmacokinetic tests that determine how humans metabolize toxicants because they advance scientific knowledge, provide unique data, and involve low doses. Biomarker studies, such as dosing volunteers with perchlorate to find out at what dose thyroid iodine uptake is inhibited, are also acceptable, provided they meet other safety requirements. To make certain such standards are followed, the committee recommends that EPA establish a Human Studies Review Board. Private studies should also comply with federal
ethical standards known as the Common Rule, which protects participants by requiring extensive oversight by an institution’s Internal Review Board and by asking for informed consent. EPA officials didn’t comment on the panel’s recommendations, but the agency announced last May that it intends to draft a rule on testing. As part of that process, EPA will evaluate the NRC report and public comments about the draft rule, according to spokesperson David Deegan. EPA hasn’t yet set a timetable for the proposal, he says. CropLife America, a Washington, D.C., trade association of pesticide manufacturers, welcomed the report. “As the [NRC] report identifies, it is in the public’s interest to maintain the availability of products that protect public health by controlling disease-carrying pests, such as mosquitoes, ticks, and cockroaches, and that ensure an abundant, affordable, highquality food supply,” a spokesperson says. Environmental groups fear that the report’s recommendations could
lead to a dramatic increase in human studies, which are typically third-party experiments conducted by pesticide companies and their contractors. “We are very concerned that the chemical industry will view the report as a green light to continue the highly unethical practice of dosing people with pesticides and industrial chemicals,” says Richard Wiles, senior vice president of the Environmental Working Group. Environmentalists view the studies as unethical because they put volunteers’ health at risk to benefit pesticide companies. The Environmental Working Group galvanized the debate on human testing with a report in 1998 that exposed chemical companies’ tests on uninformed Scottish college students. “The committee purposely set a very high bar when it comes to intentional human dosing studies, especially for those that do not promise health or environmental benefits,” says co-chair Michael Taylor, a senior fellow at Resources for the Future, a Washington, D.C.based economic think tank. —REBECCA RENNER
While studying African smoke plumes created by slash and burn agriculture, researchers have discovered a whole new category of carbon aerosol. The new particles, labeled tar balls, are significantly larger than soot and could play a role in air pollution and climate change. “Soot is well known and well studied,” says Peter Buseck, Regents Professor in the Department of Geological Sciences at the Arizona State University and one of the authors of the paper (J. Geophys. Res. 2004, 109, 1–9). “What was not known was that there are these other spherical particles that are considerably larger than soot.” These particles, he adds, suspend themselves in the troposphere and
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New particles found in smoke plumes
Transmission electron microscopy helped identify the presence of tar balls. The images above show irregular soot aggregates, and the inset on the left shows a tar ball.
thus may play an important role in both air pollution and global climate. Soot, for instance, is our atmosphere’s primary absorber of shortwave radiation. Tar balls differ from soot in three important aspects. First, tar balls have an amorphous shape and lack
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an internal crystalline structure. Second, they are an order of magnitude larger than soot particles, which typically measure around 20 nanometers. Finally, although soot is mostly composed of carbon atoms, tar balls contain a significant appear to amount of other elements, primarily oxygen.
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very unstable or highly reactive. Buseck says he found other types of particles in the smoke plumes but could only characterize the tar balls. But if other carbonaceous materials are discovered, they might help further refine climate models. Soot’s quality of reflecting radiation helps to counteract greenhouse gases. “We’re not sure about tar balls,” says Buseck. “If they’re an important part of the atmosphere, then that has potentially important implications for climate modeling.” Tar balls may also be an indicator of biomass burning. Sampling smoke plumes was part of a larger NASA project called Safari 2000, an endeavor to study emissions in southern Africa. Biomass fires sometimes start from lightning. However, an estimated 90% are caused by slash and burn agriculture, which studies have shown has risen dramatically in the past 100 years and affects the global climate. —PAUL D. THACKER
Coastal monitoring tools Monitoring related to restoration of U.S. coastal habitats is complicated by the broad diversity and geographic scope of the nation’s coasts. A new manual from the National Oceanic and Atmospheric Administration consolidates the sciencebased tools needed by coastal managers, researchers, and citizens to develop the strategies best suited to a habitat’s features. The manual includes consistent principles and approaches likely to be used in a wide range of coastal efforts. It also provides an introduction to restoration monitoring related to specific habitats, including oyster reefs, water columns, and mangrove swamps. Science-Based Restoration Monitoring of Coastal Habitats, Volume One: A Framework for Monitoring Plans Under the Estuaries and Clean Waters Act of 2000 is available at http://coastalscience.noaa. gov/ecosystems/estuaries/ restoration_monitoring.html.
After a number of fits and starts, the California EPA has finally set the first public health goal in the nation of 6 parts per billion (ppb) for perchlorate in drinking water. However, the state said that it reserves the right to modify this level if the ongoing National Academy of Sciences perchlorate health review produces a significantly different evaluation of this key rocket fuel ingredient when it issues its findings later this year (Environ. Sci. Technol. 2003, 37, 166A–167A). California has been developing a perchlorate health goal since 1998. In 2002, the state proposed 6 ppb. However, a lawsuit by Lockheed Martin and Kerr McGee mandated a second round of peer review by University of California scientists, and a deadline of March 12, 2004, was set. Before that round of review, the draft goal was revised to a range of 2–6 ppb. The public health goal is based purely on a health-risk assessment, but next year the state’s Department of Health Services
PHOTODISC
California sets public health goal for perchlorate
Perchlorate, which is used in rocket fuel and other applications, has been found in the drinking water of many U.S. states, but California has become the first to set a public health goal for the compound.
Seeing Energy Stars The Whirlpool Corp. (Ben Harbor, Mich.) received one of this year’s 57 Energy Star Awards for selling the most Energy Star-certified appliances in 2003. The company offers 352 certified base models, actively promotes saving energy in its advertising, and helps make homes more energy efficient in cooperation with Habitat for Humanity. The U.S. EPA annually recognizes outstanding contributions to reducing greenhouse gas emissions through energy-efficient innovation. Energy Star now has more than 8000 partners. Last year, the program helped Americans save $9 billion and enough energy to power 20 million homes and reduced greenhouse gas emissions by the equivalent output of 18 million cars. For a complete list of award winners, go to www.energystar.gov.
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NOAA
Stephen Schwartz, a Senior Scientist at Brookhaven National Lab, says that large amounts of oxygen in tar balls means the particles are more hydrophilic and may have interesting chemical properties. “[Tar balls] may be more susceptible to being incorporated into precipitation,” he says. “It also means that if you inhale them, they are more likely to dissolve in cellular fluids. So there’s a lot we need to learn about these things from an air quality perspective, human health, and climate influence perspective.” Tar balls were found to be very abundant in smoke plumes barely minutes to hours old. And in hourold smoke, they were the dominant particle type. Although it is not entirely understood how they materialize, their rapid appearance in smoke indicates they form by a gasto-particle conversion. And judging from the tar balls’ insignificant presence in atmosphere, their structure is thought to be either
