Government Watch
Drought curbs this year's dead zone This summer's measurements of the low oxygen area off the Louisiana coast known as the dead zone recorded the smallest zone since the 1988 drought, according to Nancy Rabalais, a marine biologist at the Louisiana Universities Marine Consortium. Mapped at 4400 square kilometers, the zone is one-fifth the size of last year's record-breaking 20,000 square kilometers. The two components necessary for stripping the water of oxygen—high nutrient flow from the Mississippi River and a layer of fresh water overlying salty Gulf of Mexico water—were much less abundant this year, thanks to drought conditions in the Mississippi basin, Rabalais says. The drought resulted in lower than average freshwater discharges from the Mississippi River and a lower flow of nutrients in March, April, and May, which contributed to this year's smaller hypoxic zone. —J.P.
targets help to get people around the table to cooperate, then they are healthy," he adds. If the plan sets an aggressive goal, there is a risk that key players in the states and agricultural industry will not sign on, admits Dennis Keeney, a senior fellow at the nonprofit Institute for Agriculture and Trade Policy in Minneapolis, MN. Of the four states with the highest nitrogen re-
leases, only Wisconsin and Minnesota are supportive of the plan's goals, while Iowa and Illinois are strenuously objecting to them. "If we can get a commitment from the agricultural industry to improve their practices, then come back and have another summit after a few years and strengthen the plan, we will eventually reach the goal," he says. —JANET PELLEY
A new route for endocrine disrupters Most studies of endocrine disruption focus on interactions with hormone receptors, particularly the estrogen receptor. Now, Thomas Sanderson and colleagues from the Netherlands' University of Utrecht and scientists from Michigan State University (MSU) are demonstrating that endocrine disrupters can work in a different way by increasing production of aromatase, an enzyme that converts androgens to estrogens. Scientists have known that many other mechanisms of potential interference with endocrine function exist, and Sanderson and colleagues are among the first to prove that this happens. In in vitro experiments using the human H295R adrenocortical carcinoma cell line, the scientists found that 2-chloro-s-triazine herbicides, atrazine, simazine, and propazine dose-dependently induce aromatase activity. At a 30-pM concentration, an appar-
ent maximum induction of about 2- to 2.5-fold was observed after the cells were exposed to the triazines for 24 hours (see figure). These cells, which are like undifferentiated human fetal adrenal cells, can produce a range of steroid hormones. "This is the first documented case, to my knowledge, of aromatase enzyme disruption and a switch from androgen to estrogen," says Lynn Goldman, former chair of the U.S. EPA's Endocrine Disrupters Screening and Testing Advisory Committee (EDSTAC), which is overseeing the development of methods to evaluate chemicals for endocrine disruption. Sanderson and co-worker's results are in agreement with environmental toxicity studies. For example, Andrew Crain and coworkers at the University of Florida-Gainesville found that atrazine induced aromatase activ-
EPA's technology-based approach stands in contrast to California's Department of Agriculture standards, proposed in September, which are designed to ensure that heavy metals do not pose a risk to human health or the environment California's risk-based standards would allow higher levels of metals in fertilizers than technology-based standards, EPA officials say. But the Fertilizer Institute, an industry group supports risk-based standards because they are healthbased and reasonable for the industry to meet Environmental grouDS say California's standards will increase heaw metal levels in farm fields
EU harmonizes emissions monitoring A European Pollutant Emission Register (EPER), similar to the U.S. Toxics Release Inventory (TRI), is expected to enhance government monitoring of toxic emissions across the European Union (EU). The European Commission (EC) adopted plans for the register under the 1996 Integrated Pollution Prevention and Control directive in late July. The TRI covers more than 600 toxic compounds whereas EPER will cover only 50 pollutgptg including greenhouse gases metals and organic and inorganic compounds according to the EC Contained in the EPER licl" hn\A/p\/or flre fl greater mini*
ber of substance groups than in the TRt uuhich tarnofrQ individual chemical species. Like the TRI, EPER's aim is public accessibility, but also emissions monitoring by governments, with governments reporting emissions directly to the EC. Most EU member states already have emissions inventories, but some are weaker than others, and they rely on different measurement methods, making communitywide comparisons difficult {Environ. Sci Technoll.999,33 (3), 61A-62A)
OCTOBER 1, 2000 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 4 1 5 A
