Environmental ▼News Musk fragrances found to be antiestrogenic ome of the synthetic musk franatural horomone17β-estradiol on Richard Schreurs, the study’s corregrances used in consumer estrogen receptors (ERs) both in sponding author. The compounds goods can impair estrogenic vitro and in vivo with transgenic could indeed affect female reprofunction in fish, according to rezebrafish. Because of the musks’ duction in fish, thereby leading to search published in this issue of high lipophilicity, the compounds problems at the population level, ES&T (pp 997–1002). The study bioaccumulated in fish as much as van der Burg speculates. reveals that these environmental 600-fold. At an aqueous concentraLittle is known about the antipollutants could be significant ention of 1 micromolar (µM), which is estrogenic activity of environmendocrine disrupters, say scientists much higher than typical environtal pollutants, says Rik Eggen, a from the Institute for Risk Assessmental levels, the compounds demolecular toxicologist at the Swiss ment Sciences at Federal Institute for Utrecht University and Environmental Scithe Netherlands Instience and Technology tute for Developmental (EAWAG). More reBiology in Utrecht. search on the exact The research focuses mechanism of antion two polycyclic estrogenic action is musks that are used as warranted because fragrances in soaps, very similar chemicals cosmetics, and cleaning can behave very differproducts and often end ently in the environup in wastewater. What ment, depending on is unique about these the conformational compounds is that they changes they induce in are the first to be rethe ERs upon binding, ported with antiestroEggen points out. genic activity on the For example, while basis of an in vivo fish nonylphenol can act as assay. While estrogenic estrogen, nonylphenol chemicals mimic the acetate acts as an antibehavior of the female estrogen. If a chemical hormone estrogen, fully activates the ER, antiestrogenic chemithe chemical–receptor cals impair the activity complex binds to DNA Those pleasant-smelling musk fragrances may contain significant of endogenous estroand induces transcripendocrine disrupters. gens. Antiestrogenic tion of certain genes, pharmaceuticals, such as tamoxcreased estradiol activity by 80%. while incomplete activation of the ifen, are used in breast cancer However, antiestrogenic effects ER leads to competitive inhibition treatment and have been studied were also seen at a musk concenof the endogenous estrogens, imextensively, but the antiestrogenic tration as low as 0.1 µM, which is a pairing their effectiveness, Eggen activity of environmental pollulevel that can be reached in sewage explains. tants has hardly been addressed so treatment plant ponds, the authors Some chemicals can act as eifar, says Bart van der Burg, an ausay. ther weak estrogens or as antiestrothor of the study. Although the in vivo study took gens, depending on the dose in The researchers investigated into account transport and metabwhich they are applied, van der two musks, 6-acetyl-1,1,2,4,4,7olism of the musks in the zebrafish, Burg adds. To make the picture hexamethyltetraline (AHTN) and the researchers acknowledge that even more complicated, antiestro1,2,4,6,7,8-hexahydro-4,6,6,7,8,8they have only identified effects at gens in humans are known to have hexamethylcyclopenta-γ-2-benthe ER level. “The most important very tissue-specific effects in addizopyran (HHCB), which were question now is, what are the eftion to their effects on the reprofound to suppress the effect of the fects on the fish [as a whole],” says ductive organs, van der Burg says. PHOTODISC
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© 2004 American Chemical Society
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Environmental▼News This implies that antiestrogens could also affect fish in a quite unexpected manner, he suggests. This study is the first step in the right direction, says ecotoxicologist John Sumpter of Brunel University in Uxbridge, U.K. He believes that the recent research emphasis on just estrogenic chemicals has not been justified because other classes of endocrine disrupters, such as antiestrogens, androgens, and antiandrogens, are likely to play
an important role as well. The real issue, however, is not the effects of individual compounds, but how organisms react to mixtures of endocrine disrupters in the environment, he emphasizes. “We have no idea at the moment how to even address this issue,” Sumpter admits, because the interactions between different chemicals, let alone from different classes of endocrine disrupters, are extremely hard to address. He points
out that the latest funding on risk assessment of chemical mixtures in the European Union—the Cluster of Research into Endocrine Disruption in Europe, which has mixtures of endocrine disrupters as one of its major foci—has a total budget of more than ¤20 million (www. credocluster.info). “This issue sweeps across all organisms, both in the environment and up to human health,” Sumpter states. —ANKE SCHAEFER
Cheap solar energy
BEN-GURION UNIVERSITY OF THE NEGEV
says, the dish must be used in conjunction with solar photovoltaic The world’s largest solar dish has the times stronger than noontime (PV) cells. He plans to use the dish potential to generate energy for sunshine. to illuminate 1 m2 of PV cells, about 5 cents (U.S.) per kilowatt To generate solar energy at a which will be actively cooled to hour (kWh), according to David price that “no other solar energy 60 °C. “Under such conditions, the Faiman, director of Ben-Gurion Uni- can come anywhere near,” Faiman cells should have a peak power of versity of the Negev’s National about 100 kW and produce Solar Energy Center in Israel, about 150,000 kWh,” he where the dish has been built. explains. In comparison, solar electricity Faiman’s calculations are generally costs around 30 cents based on using 23% efficient per kWh, according to Solarsolar cells; the economics buzz, Inc., an international would be proportionately betsolar energy research and conter if the 40% efficient solar sulting company. cells, which are expected to be The 400-square-meter (m2) available soon, were used, he dish, which is known as the says. He also notes that the Photon Energy Transformer 60 °C cooling water could be and Astrophysics Laboratory reused for purposes such as (PETAL), can generate approxrefrigeration or water desalinimately 400 kW of thermal enization projects. —KELLYN Israel’s giant solar dish collector could lower costs ergy at intensities up to 10,000 to 5 cents per kilowatt hour. BETTS
Climate change technology reports criticized Two reports quietly released in December by the Bush Administration on how the Climate Change Technology Program (CCTP) is better coordinating research related to greenhouse gas mitigating technologies across 14 government agencies have drawn criticism from technical experts. The reports shed no light on budgeting priorities, nor do they provide as much detail as their critics deem necessary. The reports, which offer the most detailed information to date on the year-old CCTP, describe 87 activities in 18 far-flung research areas, which include the FreedomCAR program, nuclear power gener-
ation, carbon sequestration, and reduction of sulfur hexafluoride emissions from magnesium production. After the CCTP was introduced in November 2002, critics called on the Department of Energy (DOE) to give the solutions to climate change equal time with the science; the reports address some of those issues. In his State of the Union address in 2003, Bush responded to those critics—and the nation as a wholeby saying, “In this century, the greatest environmental progress will come about not through endless lawsuits or command-andcontrol regulations, but through technology and innovation.” A year
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later, however, critics charge that the long-awaited reports describing the technology that the nation is developing don’t go far enough. DOE needs to do more, complains Sudhir Chella Rajan, a senior scientist with the Tellus Institute, a nonprofit organization focused on sustainable development. “What is frustrating about the CCTP document … is that it looks like a giant publicity brochure with technology profiles but no serious analysis of their potential, costs, integration with existing systems, or aggregate emissions reduction impacts over the medium and long term. In the absence of explicit emissions reduction goals and a timetable to strive for, the sanguine technologi-
