Environmental▼News cient evidence of significant global adverse impacts to warrant international action to reduce the risks to human health and the environment arising from the release of mercury into the environment.” It also supported the action plan to provide technical assistance and advice to all countries—particularly developing nations and transition countries, such as those in the former Soviet Union—on ways to cut mercury emissions from major sources, such as coal-fired power stations and incinerators. UNEP will also advise countries on introducing clean coal technologies, improving power station efficiency, switching to other forms of electricity generation, and reducing other sources of mercury pollution, such as those from contaminated waste sites and dental amalgams. It will also help countries develop public awareness programs on the risks of mercury exposure, particularly for vulnerable groups such as pregnant women.
Everyone agreed that most of UNEP’s work should focus on assisting developing countries immediately, explains Jim Willis of UNEP’s chemicals unit. This was mainly because most developing countries are not ready to negotiate a treaty without better understanding the issues in their own countries, he says. “I believe that everyone, even the U.S., was satisfied with taking immediate action now, and looking at other options—including treaty options— at the next Governing Council.” The European Commission maintains that it is “not unhappy” with the meeting’s conclusion, according to a spokesperson. Although it wanted a binding treaty, it recognizes that this outcome still leaves the door open for all policy options in the future. However, discussions on a binding treaty could be deferred to 2005, which is the UNEP Governing Council’s next meeting. In a letter to President Bush in
February, several members of the U.S. Congress expressed their disappointment with the U.S. position. They cite a leaked State Department document that directed the U.S. negotiators to block any attempts to move forward on a binding convention and to oppose even voluntary targets or any timetables for action. The letter’s signatories say they are concerned that the Bush administration’s stance is weakening the United State’s credibility on environmental matters and spurring resentment in the international community. Environmental groups were also disappointed. “No single country can resolve the mercury problem on its own; there needs to be a binding global solution,” says Michael Bender of the Ban Mercury Working Group, a coalition of environmental and human health organizations. “There are alternatives for mercury uses, but there is no alternative to global cooperation.” —MARIA BURKE
CDC pegs human exposures to chemicals chemicals: metals, tobacco smoke, organophosphate pesticides, and phthalates. The second expands on these and reports on 12 groups of chemicals, including dioxins, furans and PCBs, herbicides, pest repellents, disinfectants, and phytoestrogens. The report establishes exposure baselines, or reference ranges, that PHOTODISC
Signifying “a quantum leap forward” on understanding environmental chemicals and how much is being absorbed by humans, officials with the U.S. Centers for Disease Control and Prevention (CDC) released their Second National Report on Human Exposure to Environmental Chemicals. It contains good news about declining children’s blood lead levels and exposures to tobacco smoke for nonsmokers, but some say it raises concerns about mercury levels. We are “pretty excited,” says David Fleming, CDC’s deputy director for science. “It is almost the most extensive study ever made of exposures to environmental chemicals.” The report is four times larger than CDC’s first 2001 document and relies on blood and urine specimens taken in 1999 and 2000. It includes data on 116 chemicals, 89 of which have never been measured in the U.S. population, such as polycyclilc aromatic hydrocarbons and carbamate insecticides. The first report measured levels of four groups of
The CDC’s second report on human exposures to environmental chemicals finds that levels of the metabolite 2-ethylhexyl phthalate, which tracks exposure to di-2ethylhexyl phthalate commonly found in soft plastic products, were higher in kids. Yet no generally recognized guidelines that indicate values for adverse health effects for these levels are available.
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public health investigators can refer to when deciding whether an acute exposure, such as an accidental factory release, has harmed nearby residents. Regulators, too, can refer to the baselines to evaluate the effectiveness of controls. A more difficult but potential use would be to evaluate multiple exposures, suggests George Lucier, former director of the National Toxicology Program. Released in January, the data support government efforts to control substances suspected of a human health link, the authors maintain, especially with respect to bans on tobacco smoke. For example, levels of cotinine, a metabolite of nicotine, have decreased 58% for children, 55% for adolescents, and 75% for adults when compared with levels measured in 1991–1994. At the same time, recent data show that cotinine levels in kids were more than twice the levels of adults, and levels in African Americans were more than twice the levels of Mexican Americans or whites. “Continued efforts to reduce expo-
sure to environmental tobacco smoke are warranted,” the authors say. Children were also found to have twice the levels as adults of chlorpyrifos and other commonly used organophosphate insecticides in their bodies. Levels of phthalates commonly found in soft PVC plastic products, particularly the more toxic phthalates, were higher in children than in adolescents and adults. The data, however, doesn’t link exposures to disease, cautions Richard Jackson, director of CDC’s National Center for Environmental Health. From a regulatory perspective, there weren’t enough people in the study to determine whether the exposures exceed regulatory levels, and for many of the chemicals, there are no regulatory levels, adds Lynn Goldman, a former EPA official, and now a professor with the Johns Hopkins School of Public Health. Except perhaps for mercury, Goldman and several other researchers add. “As I looked at those 116 chemicals, the ones that showed levels that were close to or at levels that could cause effects in people, methyl mercury stood out,” says Lucier. The data show that “somewhere between 5 and 10% of women of childbearing age would exceed EPA’s [oral reference dose] for methyl mercury. This is far too many,” Lucier adds. Public health advocacy groups hailed the report, and several released their own studies designed to interpret CDC’s data or to link exposures and disease risk. Others called on Congress to provide states with better biomonitoring capabilities. “A comprehensive biomonitoring capacity could be used to do double duty, to protect our nation’s health by detecting environmental exposures and potential terrorism events,” says Shelley Hearne, executive director of Trust for America. CDC officials plan to release future reports of exposure to cover two-year periods, with the next for 2003−2004. For a copy of the report, go to www.cdc.gov/exposurereport. CATHERINE M. COONEY
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