Environmental ▼News Biomarkers pass test in regulatory setting
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© 2004 American Chemical Society
ample, when biomarkers are used to assess the pollutant loads of a harbor, they can target contaminated sites, thereby limiting the areas where more expensive testing is necessary. “With six to eight carefully chosen biomarkers, researchers can select which additional tests are needed by identifying whether the organisms are responding to pesticides versus fuels versus metals,” he adds.
Looking at various biomarkers may be the easiest way to determine how pollution affects crabs such as these.
Galloway and her colleagues selected nine easy-to-analyze biomarkers, such as induction of the metal-binding enzyme metallothionein and the stability of cellular lysosomes, to measure pollutant exposure and health effects. The researchers analyzed the biomarkers in 450 animals from 3 different trophic groups represented by a crab, a clam, and a snail, which they collected from the head to the mouth of the heavily developed Southhampton Water estuary. They also measured levels of tributyltin, polyaromatic hydrocarbons, and pesticides in the water and sediments. Statistical methods showed which animals and indicators were most sensitive to which pollutants, Galloway says. For example, the crab, Carcinus maenus, was the
JEFF GODDARD, UNIVERSITY OF CALIFORNIA, SANTA BARBARA
esearch published in this issue of ES&T (1723–1731) demonstrates for the first time that the use of multiple biomarkers can be a practical way to assess the impact of pollutant exposure for invertebrates, such as crabs and clams, in a regulatory setting. The research shows how to overcome barriers to incorporating biomarkers into environmental risk assessments and could also help build a case for taking an evidence-based approach to regulating pollutants, says one of the paper’s authors, Michael Depledge, head of science at Britain’s Environment Agency. By using a suite of biomarkers, the study uncovered a gradient of chronic health impacts on organisms in a marine estuary in southern England, says the paper’s lead author, Tamara Galloway of the University of Plymouth. Conventional monitoring does not always reveal such health effects, she says. “Biomarkers employ routine techniques from human medicine, such as blood and urine sampling, to measure the health of organisms in relation to pollutant levels,” Depledge explains. The biomarkers detect if there has been exposure to contaminants, tell how the animals’ health is affected by exposure, and get to the heart of linking pollutants to ecological effects, he says. Although the technique holds lots of promise, regulatory agencies have been reluctant to adopt it because of concerns about expense and complexity of interpretation, Galloway says. However, the cost of a biomarker assay has plummeted to $35 per assay per sample, a fraction of the cost of a PCB assay, which can run from $800 to $1800 per assay per sample, says Craig Downs, president of Envirtue Biotechnologies, a biomarker testing company. For ex-
most sensitive to contamination, and biomarkers, carboxylesterase activity, metallothionein induction, and total haemolymph protein were the best indicators of pollution differences between the sites along the estuary. “Galloway and her colleagues have shown that suites of biomarkers can reveal contaminant gradients in the environment, identify where pollution is occurring, and link exposure to adverse health effects,” says Peter Wells, a research scientist with Environment Canada. Although the research tells us about the health of organisms in the system, it doesn’t say anything about the survivability of their populations—the “holy grail” of ecotoxicology. However, Galloway’s research is moving in that direction, and in a few short years it may be possible, he adds. Depledge points out that regulatory actions increasingly are being taken in response to effects on the health of organisms, for example, the appearance of tumors, or sex changes associated with endocrine disruption, without needing to demonstrate population level effects. Because of the growing number of reliable biomarkers and the lower cost to analyze them, Environment Canada is considering standardizing biomarker assessment methods and inserting them into regulations for environmental monitoring, Wells says. The European Union’s new Water Framework Directive, now being phased in after passage three years ago, is one of the driving forces behind biomarker research, Depledge says. Placing a greater emphasis on regulating biological effects rather than levels of contaminants, the framework states that chemicals that cause ecological harm should not be discharged.
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Environmental▼News “This is the first time that a law in Europe has focused on a biological endpoint to prevent ecological harm,” Depledge says. Developing a robust suite of biomarkers that can be used with a wide range of inver-
tebrates, not just fish, will help ensure compliance with the new law. Moreover, by demonstrating that contaminants affect the health and well-being of organisms, the biomarker analysis could lead to a pre-
EPA FY ’05 budget: More or less? President Bush’s fiscal year 2005 (FY ’05) budget, released in February, requests $7.76 billion for the U.S. EPA—a $130 million increase over the administration’s FY ’04 proposal but as much as 7% less than the $8.4 billion Congress appropriated. The overall science and technology (S&T) budget takes a bigger hit in the proposed budget, dropping some $93 million, or 12%, from congressional funding for FY ’04. In announcing the budget, EPA Administrator Mike Leavitt focused on the program funds that would increase when they are compared to Bush’s request for last year, rather than comparing the figures to what Congress provided. Leavitt touted the requested $33 million for the agency’s operating programs—a 1% increase over Bush’s request last year—that would be the highest funding level in history, he said. These funds support the agency’s core regulatory, research, enforcement, and state grant programs. Leavitt pledged to “pursue even better ways to care for the environment and protect people’s health [by] increasing the velocity of improvement.” He added, “The approach of the last 30 years has been too slow, too expensive, and produced too much conflict.” To accomplish these goals, Leavitt said that EPA would be more focused on results than programs, relying on market incentives, collaborative networks, and technology. A number of Democrats and others in Congress criticized the request, including Sen. James Jeffords (I-Vt.) of the Senate Environment and Public Works Committee. The request cuts funding for almost every program the committee oversees, Jeffords said, such as a $21 million, or 3%, cut for the clean air and
global climate change programs. The new budget still needs to get through Congress, and in recent years lawmakers have added significant “earmarks” for special projects in individual members’ districts. EPA budgeters tried to impose some discipline by removing as much as $524 million in last year’s earmarks from the budget request. The earmarks included $52 million for research, said Paul Gilman, EPA’s Science Advisor and head of the Office of Research and Development. EPA’s requested FY ’05 S&T budget is $689.1 million. Within this budget, EPA is asking for a $4 million increase, from $8.9 to $13 million, for computational toxicology, a request that most likely reflects Gilman’s emphasis on bringing life sciences methods into the agency. Increases are also requested for air toxics research (from $15.7 to $17.6 million) and for particulate matter research programs (a slight amount that will bring the PM research total to $63.7 million). The S&T cuts would be spread across programs targeting endocrine disrupters (from $12.9 to $8 million), pollution prevention (from $38.9 to $34 million), land protection and restoration (from $36.5 to $33 million), pesticides and toxics (from $36.7 to $29 million), and human health and ecosystems (from $190.7 to $144.7 million), Gilman said. Most other research programs would receive small funding increases or remain the same, while some would see minor funding decreases. However, funding for the Science to Achieve Results (STAR) program to support university grants would be cut by $35 million, to total $65 million. Under the request, 5 of the 14 or 15 projects EPA intended to
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ventative approach whereby chemicals are regulated on the basis of health risks, rather than on the need to prove a connection to actual declines in animal populations, he says. —JANET PELLEY
pursue in FY ’05 would not be funded, Gilman said. When Leavitt unveiled the budget, he highlighted a number of requested increases, including a $60 million increase, to $65 million, for the Clean School Bus USA program. The funds will help school districts replace pre-1991 school buses with those offering state-ofthe-art emission controls and retrofit post-1990 school buses. Bush proposed a 10% increase in Superfund monies, which will fund 8–12 new construction starts in 2005 and a similar number in 2006. Environmental groups, however, complained that Congress has not reinstated the Superfund tax on the oil, gas, and chemicals industries and therefore taxpayers, rather than the industries that created the pollution, are footing the cleanup bill. Leavitt also announced a $45 million, or fivefold, increase in funds for the Great Lakes Legacy program to support sediment remediation at six sites and a $10 million pilot program to reduce nutrient input into the Chesapeake Bay. Bush tagged on an additional $1 million for invasive species and another $20 million for water quality monitoring, the latter having emerged as a major topic. Environmental groups complained that these targeted funds would be offset by the huge decrease in funding Bush proposed for water quality: the elimination of $492 million from last year’s budget for the Clean Water Act State Revolving fund, which helps states build sewage treatment plants. Bush proposed a similar cut last year, and Congress reinstated almost $500 million for the program. Funds for nonpoint source pollution control drop by $30 million. —CATHERINE COONEY and ALAN NEWMAN
