Perchlorate regulation faces further delay - Environmental Science

May 1, 2003 - Mark Heinnickel , Stephen C. Smith , Jonathan Koo , Susan M. O'Connor , and John D. Coates. Environmental Science & Technology 2011 45 (...
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Environmental▼News fallen by 5% since 1997 when Blair took office, mainly due to the closure of several coal-fired power plants. The 60% goal is a substantial hike from the United Kingdom’s current domestic target of reducing CO2 emissions by 20% by 2010. The goal was part of a white paper issued by the Departments of Trade and Industry; Transport; and Environment, Food and Rural Affairs, which discusses all aspects of energy in Great Britain for the next 50 years. The plan relies heavily on renewable energy, with wind and solar power providing 20% of electricity by 2020. Currently, renewables provide only 3%. Toward this goal, the government has pledged an extra $90 million for renewables, increasing spending to $580 million over four years. The plan’s other focus is on improving energy efficiency, including developing energy-efficient building regulations and tougher energy standards for new homes and electrical products. However, the white paper warns that the new policies could raise costs for household electricity

5–15% by 2020, industrial electricity by 25%, and industrial gas up to 30%. The white paper notes that nuclear power is “an unattractive option”, but the authors don’t rule out new nuclear plants in the future. This stance on nuclear power, as well as the declaration to support renewable energy, contrasts sharply with the Bush administration’s energy policy. In their January budget request to Congress, the administration proposed new funding for nuclear power, clean coal technologies, and hydrogen fuel cells, but mostly reduced monies for renewable energy programs (Environ. Sci. Technol. 2003, 37, 128−129). There is considerable skepticism about the United Kingdom’s ambitious goals. Cambridge Econometrics (CE), an independent economics consultancy, has forecast that the country will miss its goal of reducing emissions by 20% by 2010 and will see only an 8% reduction. Economists also predict that carbon emissions will go up after 2015 as nuclear plants are decommissioned. “The government is

Perchlorate regulation faces further delay A controversial U.S. toxicological review of perchlorate has taken an unexpected twist: The final review, which was due out early this year, is being delayed because the EPA, the Department of Defense (DoD), and several other U.S. agencies have decided that the National Academy of Sciences (NAS) should now review the issue. EPA’s January 2002 draft toxicological report recommended a drinking water limit of about 1 part per billion (ppb). DoD, however, thinks that this analysis is flawed for many reasons, but particularly because EPA relies primarily on lab animal data, according to an Air Force spokesperson. DoD wants to place more emphasis on human data. The decision to ask for the review was based on interagency talks between officials from EPA,

DoD, NASA, the White House’s Council on Environmental Quality, and the Office of Management and Budget that have been going on for some time, according to William Farland, EPA’s Office of Research and Development acting deputy administrative director for science. The NAS review is likely to take about two years and will delay any regulatory action on perchlorate. Perchlorate can reduce thyroid hormones by inhibiting iodine uptake. Because thyroid hormones play an important role in brain development, EPA used a battery of neurodevelopmental tests with rats to estimate the risks of perchlorate exposure. The laboratory experiments used in the perchlorate review are part of EPA’s approved battery of neurodevelopmental tests and include measurements of brain size

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assuming the 2010 reductions are in the bag, but our forecasts cast doubt on this, making the 2050 goal even more challenging,” says CE’s Sudhir Junankar. New measures, including energy taxes are needed in addition to those recommended, he says. The white paper also fails to discuss emissions from road transport in any detail, which will continue to grow, Junankar adds. Environmental groups welcomed the plans but warned that the new policy omits clear timetables, targets, and investments, especially with regard to renewables. The government has indicated a difference between a target, which is a firm objective, and a policy goal, which is what they hope to meet but can’t be held to. Although some pieces of the white paper need legislative approval, most of it pertains to medium- and longterm policy. The white paper, Our Energy FutureCreating a Low-Carbon Economy, is available at www.dti. gov.uk/energy/whitepaper/index. shtml. MARIA BURKE and CATHERINE COONEY

and shape, animal behavior, and thyroid hormone levels. But the report of the external peer review committee that evaluated the current draft toxicological review indicates that some of the reviewers were concerned about the quality of the experimental studies. Some reviewers noted that the work on rat thyroid hormone levels did not detect consistent effects either within, or across, several studies. The experts believe that this happened because the labs chose an analytical setup that was not sufficiently sensitive to reliably measure low levels of thyroid hormones in the rats. In addition, most of the reviewers agreed that the measurements to characterize brain dimensions were subject to serious artifacts. This is because small changes in the orientation of the brain slices used to determine size dramatically affect the measurements, according to neurotoxicologist Michael Aschner

hearings on March 19. Studies already conducted involving healthy human adult volunteers suggest that it takes much higher doses of perchlorate to harm humans, according to the scientists who did the studies. Oregon Health and Science University professor Monte Greer and colleagues estimated that 5.2−6.4 micrograms per kilogram per day would have no effect on iodine uptake. This is approximately the adult dose from drinking water containing perchlorate at 180 or 220 ppb, well above the draft standard. The conflict between the animal and human studies is a red herring, according to Grant Anderson, who studies thyroid hormones and brain development at the University of Minnesota Department of Medicine in Minneapolis. This is because adults are not the most vulnerable population. In humans, it is widely acknowledged that thyroid hormones exert their greatest effect on brain development when the developing child is making its own thyroid hormones—late in pregnancy and after a baby is born, he says. This means that the effects of perchlorate on an adult’s iodine uptake or thyroid hormone status are not the most relevant data for assessing how perchlorate exposure affects the developing brain. —REBECCA RENNER

Mercury action and inaction

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Opposition from the United States has blocked a European proposal to begin negotiations on an international protocol to limit mercury

UNEP will provide technical advice on limiting mercury emissions from various sources, including dental fillings.

emissions, but the international community did agree on an action plan to provide technical assistance and advice on ways to reduce sources of the toxic element to developing nations. At the Governing Council of the United Nations Environment Programme (UNEP) meeting in Nairobi in February, the U.S. delegation argued that an international agreement to limit emissions would take too long and cost too much to negotiate and instead supported only “technical assistance and capacity-building activities.” The council did agree with UNEP experts (Environ. Sci. Technol. 2002, 36, 441A–442A) that “there is suffi-

News Briefs U.S. fulfilling environmental treaties For the most part, the United States is following through on commitments made under five key international environmental treaties relating to climate change, ozone depletion, and trade in endangered species, concludes the U.S. General Accounting Office (GAO) in a recent report. The agency finds that actions to date have had a positive effect on the environment. The United States fell short, however, on pledges of financial assistance to developing countries and in efforts to reduce greenhouse gas emissions to the 1990 level by 2000. International Environment: U.S. Actions To Fulfill Commitments under Five Key Agreements (Report No. GAO-03249) can be accessed at www.gao. gov.

Hazardous playgrounds Children playing on wooden structures treated with chromated copper arsenate (CCA), a widely used wood preservative, face an increased risk of developing lung or bladder cancer, finds the U.S. Consumer Product Safety Commission (CPSC). This new research seems to contradict EPA’s position that CCA-treated wood does not pose unreasonable risks to the public or the environment (Environ. Sci. Technol. 2003, 37, 89A). To minimize exposure, CPSC now recommends that children’s hands be washed immediately following play on wooden play equipment. CPSC and EPA are studying ways to reduce the amount of arsenic leached from CCA-treated wood. For more information, go to www.cpsc.gov/phth/ ccastatement.html.

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at Wake Forest University School of Medicine, in Wake Forest, N.C., who led this aspect of the peer review. “There is no dose–response relationship, no consistency, there’s just a zig-zag.” In addition, two studies done in 1998 and 2001 “are not reproducible; there’s absolutely no consistency between the two, ” says Aschner. But EPA toxicologist Kevin Crofton argues that the overall data are convincing. “There is variability between studies, and some of this reflects the difference between labs and the difficulty of the studies. But everybody who has ever looked at thyroid hormones sees these effects, so they must be real,” he says. In addition to concerns about the crucial animal studies, some of the reviewers recommended that EPA give more consideration to studies with human volunteers. This is also what the military wants, according to the Air Force’s written comments on the toxicological review. EPA had asked NAS two years ago to consider the acceptability of human volunteer studies conducted by nongovernmental organizations. The agency’s interim policy is to refuse to accept such studies until it receives NAS recommendations and revises its policy. However, the NAS committee examining the issue was still holding