Government▼Watch UNEP’s voluntary mercury approach Ministers from 140 countries have unanimously agreed to pursue voluntary steps to reduce mercury in the environment, rather than set reduction goals as EU leaders had sought. The framework for the collaborative Partnerships for the Reduction of Mercury agreement was introduced by U.S. representatives. The guidelines satisfied the concerns of many officials from developing countries, who noted that they lacked the resources or technology to meet a mandatory reduction goal. Meeting as the UN Environment Programme’s (UNEP) governing council in Nairobi, Kenya, in February, officials agreed to review the success of this voluntary approach in two years. They also asked UNEP to determine the amounts of mercury being traded and supplied, to research how mercury moves around the planet, and to conduct a global assessment of cadmium and lead transport, UNEP officials say.
EU officials had proposed a treaty with phase-out deadlines for mercury exports, with a final deadline of 2011. But the U.S. delegation worked closely with the 100 or so developing countries making up the G-77, as well as China, to ensure that the voluntary approach would succeed, a state department official says. “Unfortunately, the agreements announced today are weak,” says Llewellyn Leonard of groundWork, a South African environmental group. “They will not ensure that mercury will not be dumped on developing nations.”
The United States has provided about $1.5 million, or close to 80%, of the funding for the UNEP mercury program, explains Richard Boucher, a spokesperson for the U.S. Department of State. “We should all put our effort into really getting into doing the work of reducing mercury emissions and not spend something like five to eight years negotiating and bringing into force a treaty,” Boucher says. The international mercury program is helping countries develop the tools necessary to create mercury inventories, says Maria Doa with EPA’s Office of Prevention, Pesticides, and Toxic Substances. EPA is playing a key role in the U.S. partnerships. UNEP will organize the partnerships and will release a list of the first ones in September. Likely efforts from the United States include sending experts in mercury and multipollutant control technologies to developing countries or passing along knowledge related to goldmining, Doa says. —CATHERINE M. COONEY
Cancer risk guidelines factor in children The U.S. EPA’s new cancer risk guidance addresses for the first time the likelihood that children are more susceptible than adults to mutagenic carcinogens. The final guidance, issued in March, also clarifies recommendations for assessing carcinogens that do not cause cancer below a threshold dose. Scientists from EPA, states, and industry will use the guidance when they perform risk assessments on chemicals. The final guidance is similar to what the agency proposed two years ago (Environ. Sci. Technol. 2003, 37, 204A). For mutagenic chemicals that cause cancer, EPA estimates that exposures to children less than 2 years old are 10 times as risky as adult exposures. Exposures for 2–16 year olds are 3 times as risky, and exposures over the age of 16 are comparable with adult exposures. In previous guidance, childhood exposure was treated as equally risky as adult exposure. The additional risk factors could have a major impact on water-quality regulations for mutagenic chemicals, according to toxicologist Erin Snyder, with engineering consultants Black & Veatch. For example, if disinfection byproducts were regulated on the basis of mutagenicity in early life stages,
© 2005 American Chemical Society
then the regulations could become more stringent, she explains. Others suggest that the guidelines could also result in more expensive contaminated-site cleanups. For chemicals that are not mutagenic and for which the mechanism of action is understood, the guidelines make it clear that the agency will favor data analysis over default assumptions, according to EPA Acting Deputy Administrator William Farland. For example, chloroform doesn’t cause cancer below a threshold dose in rats and mice, so the data wouldn’t support an analysis that attributed risk to doses below the threshold. Default assumptions are numerical values that the agency uses when data are uncertain or missing. A new section in the final guidance allows industries to call for “expert elicitation”, a provision that could lengthen an already long evaluation of cancer-causing chemicals. Expert elicitation requires that the views of experts be formally polled before a standard is finalized. The cancer guidelines and supplemental guidance are available at http://cfpub.epa.gov/ncea/cfm/recordisplay. cfm?deid=116283. —REBECCA RENNER
JUNE 1, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY ■ 237A
