Mercury goes up in wildfire smoke - Environmental Science

Mercury goes up in wildfire smoke. Rebecca Renner. Environ. Sci. Technol. , 2001, 35 (21), pp 439A–440A. DOI: 10.1021/es0125321. Publication Date (W...
1 downloads 0 Views 16MB Size
Environmental M News Arctic may be naturally generating reactive gaseous mercury

T

434 A

I

natural sources, he says. Previously, researchers believed that the presence of this form of mercury in the troposphere was attributable almost exclusively to man-made combustion sources, such as coalfired power plants.

STEVE BROOKS. OAK RIDGE ASSOCIATED UNIVERSITIES, NOAA

he arctic environment is generating the highest levels of reactive gaseous mercury ever recorded in the atmosphere, says Steve Lindberg, a research corporate fellow at the Oak Ridge National Laboratory. This form of mercury was previously believed to be produced only by anthropogenic sources like coal-fired power plants. Lindberg’s findings indicate that mercury is accumulating at unprecedented levels in arctic snow and hint that the pole could be a missing sink for between 50 and 500 tons of mercury. Building on research showing that levels of gaseous elemental mercury drop precipitously during the arctic spring (Nature 1998, 394, 331), Lindberg and his colleagues have been investigating the hypothesis that this elemental mercury, Hg(0), is being converted to reactive gaseous mercury, Hg(II). Together with Steve Brooks of the U.S. National Oceanic and Atmospheric Administration (NOAA), Lindberg made the first measurements of reactive gaseous mercury in the Arctic. They found levels of more than 900 picograms of Hg(II) per cubic meter of air (pg/m3), a lot more reactive mercury than they expected. But Lindberg acknowledges that Canadian scientists led by William Schroeder (author of the Nature paper) are investigating an alternative explanation that the formation of “filterable” (or particulate) mercury is behind the observed elemental mercury drops. If Lindberg’s findings are corroborated, they represent the first documented case in which high levels of reactive gaseous mercury are being generated in ambient air by

levels that Lindberg reported are higher than what has been recorded downwind of coal-fired power plants, he says, noting that the only higher levels he is aware of were recorded inside a chloralkali plant. And the Hg(II) concentrations are all the more notable because the research station where they were measured in Barrow, AK, is thousands of miles away from any major sources of reactive gaseous mercury, he adds.

Each year, after the annual sunrise in January, the levels of elemental gaseous mercury, Hg(O), in the environment around Barrow, AK, begin to drop. Scientist believe that the Hg(O) is being converted into reactive gaseous mercury, Hg(II).

Because the drops in elemental mercury mirror the Arctic’s cyclical depletions of ozone, Lindberg’s team suspects that a common culprit may be responsible for both generating reactive gaseous mercury and depleting ozone. The researchers are currently investigating the possibility that a combination of UV light and reactive brominated compounds is behind the fluctuations because their levels tend to rise in tandem with falling elemental mercury and ozone concentrations, but the scientists have not ruled out the possibility that chlorinated compounds are also involved, Lindberg says. The reactive gaseous mercury

ENVIRONMENTAL SCIENCE & TECHNOLOGY / NOVEMBER 1, 2001

The researchers have also been recording high levels of mercuryincluding methylmercury, which is a neurotoxicant to animals and humansin Alaskan snow in collaboration with Canadian scientists from the University of Manitoba. Lindberg’s team has found levels of up to 94 nanograms of total mercury per liter of snow (ng/L), and he says that other Canadian researchers have recorded levels of more than 200 ng/L. Lindberg says that he is certain that this mercury is being deposited in the snow by the reactive gaseous mercury in the atmosphere. Some of the snowbound mercury ends up in the runoff when © 2001 American Chemical Society

once in the atmosphere, he explains. Lindberg predicts that his findings may force a reevaluation of how regulators deal with mercury because the U.S. EPA’s report to the U.S. Congress focused on gaseous Hg(II) emissions from existing regulated sources like coal-fired power plants. The new findings imply that sources of elemental mercury such as mining, contaminated soils, and natural emissions may be contributing to the problem in the Arctic. Although the EPA decided to begin regulating mercury from power plants in December 2000, an agency spokesperson says that it is too early to speculate how this research could affect EPA’s mercury policy. Scientists have begun measuring mercury levels elsewhere in the Arctic and in the Antarctic to determine how broadly these fluctuations are being experienced. KELLYN S. BETTS

Reducing greenhouse gases in New England and eastern Canada Eleven leaders from New England and eastern Canada have signed an ambitious agreement to reduce greenhouse gas emissions to 1990 levels by 2010, underscoring their belief that global climate change is having a negative effect on the region’s economy and health. The pact is the first bilateral agreement of its kind, asserted New Brunswick Premier Bernard Lord. The Climate Change Action Plan was signed August 27 at the 26th annual meeting of the New England Governors and the Eastern Canadian Premiers (NEG/ECP) in Westbrook, CT. It calls for the governments to cooperatively develop a regional emissions monitoring program for all greenhouse gases, including CO2, nitrous oxide, and methane. This will allow the governments to monitor their own, and each other’s, progress. The plan’s long-term goal is to

reduce all greenhouse gas emissions to a level “that eliminates any dangerous threats to the climate,” says New Hampshire Governor Jeanne Shaheen (D). Once emissions are cut to 1990 levels in 2010, the leaders pledge to further reduce emissions 10% below 1990 levels by 2020. The plan urges the governments to develop programs to cut CO2 emissions from electric power plants, promote lower-carbon fuels, and reduce energy consumption through energy-efficient technologies and conservation. To reduce emissions from the transportation sector, the group will consider adopting alternative-fuel vehicle requirements similar to the vehicle programs in place in California and Massachusetts, says John Shea, director of energy and environment programs for the New England Governor’s Conference, Inc.

Government Watch Toward greener transport European companies must transport more goods by rail and ship if Europe is to meet its commitments under the Kyoto Protocol on climate change, according to a white paper on transport policy released by the European Commission (EC) in mid-September. Current trends show increasing pressures on the environment caused by road and air transport, which is growing at a faster rate than the economy as a whole, finds a recent report by the European Environment Agency (EEA), an environmental information agency of the European Union (EU). Transport is responsible for 24% of the EU’s total anthropogenic emissions of carbon dioxide, the main greenhouse gas, with road transport alone accounting for 84% of this share. Unless new measures are taken, freight traffic by road will increase almost 50% over 1998 levels by 2010, according to the report. Key among some 60 recommended measures to reverse these trends is an EC proposal to shift the balance in the transport sector from road to railways, maritime transport, and inland waterways through investment in infrastructure and a transEuropean transit network. Likewise, to encourage use of the least polluting modes of transport, the EC recommends moving toward tax structures that differentiate among the various modes of transportation on the basis of their external costs, including environmental damage, accidents, and congestion. Currently, cars, trucks, and planes have the highest external cost per unit transported, according to the EEA. The EC’s proposal now goes to the European Parliament and

PHOTODISC

the snow melts in the arctic spring, which Lindberg characterizes as “a bad time for the arctic ecosystem.” Canadian researchers have found elevated mercury levels in bird eggs and some large mammals, he says. These mercury levels have been rising over the past 20 years, the same period in which levels of UV-B radiation have been escalating. The levels of methylmercury in the snow jump dramatically between January and May, rising as high as 0.7 ng/L, which Lindberg characterizes as “unusually high for a rain or snow sample.” However, Lindberg stresses that “none of us believe that the reactive gaseous mercury deposited to snow is being methylated in the snowit’s just too darn coldbut that it must originate elsewhere.” He says that researchers believe the ocean may be the source of the methylmercury: The methylmercury in snow may arise from ocean upwellings where dimethylmercury forms; it decomposes to methylmercury

Continued on Page 437A

NOVEMBER 1, 2001 / ENVIRONMENTAL SCIENCE & TECHNOLOGY

I

435 A

Environmental M News Labrador Sea

NEWFOUNDLAND

QUEBEC PRINCE EDWARD ISLAND NEW BRUNSWICK

NE MAI VT

NOVA SCOTIA

NH

S MAS N I CON R

Spurred on by their successful efforts to control mercury emissions and acid rain precursors under previous accords, the leaders of these 11 jurisdictions signed a greenhouse gas reduction agreement more ambitious than the international Kyoto Protocol on climate change.

Another option under consideration for the states and provinces is to increase auto fuel efficiency standards, Shea adds. A steering committee with representatives from all 11 governments plans to meet in November to turn these ideas into specific regional reduction goals for each greenhouse gas, as well as both regional and state-specific programs aimed at cutting all greenhouse gas emissions, Shea says. “This agreement sends a powerful message to the rest of the [United States] about the importance of working cooperatively to cut pollution and clean up our air,” adds Shaheen. New Hampshire has already hired a climate change specialist to help state leaders focus on reducing greenhouse gases. Shaheen urged other U.S. states to follow New England’s lead. Signed by a bipartisan group of U.S. governors—three Republicans, two Democrats, and one Indepen436 A

I

dent—the pact is seen by many as sending a message to the U.S. White House to support the international Kyoto Protocol on climate change. President Bush strongly criticizes the protocol, saying that it will harm the U.S. economy, and asserts that the United States will not abide by its terms. That agreement has a more ambitious goal and calls on the United States to generally reduce greenhouse gas emissions to 7% below 1990 levels by 2010. The Canadian Parliament supports the Kyoto Protocol and is expected to ratify it this spring, says David Coon of the Conservation Council of New Brunswick, an environmental group. The NEG/ECP signatories say their agreement is not meant to criticize the United States or any other government, according to Shea. “We said we have an opportunity here, because of our unique relationship and success dealing

ENVIRONMENTAL SCIENCE & TECHNOLOGY / NOVEMBER 1, 2001

with mercury and acid rain, to deal with a common problem,” Shea says. “We thought we would clean up our own shop, regardless of what the rest of the world is doing.” Although Bush’s energy plan promotes—and some electric companies are pursuing—technologies to reduce CO2 emissions, they continue to rise in the United States. The most recent figures from the U.S. Energy Information Agency show that U.S. CO2 emissions rose by 3% in 2000, or 41 million metric tons above 1999 levels. No business group or energy producer in New England has volunteered support for the NEG/ ECP’s climate plan, says Shea. Still, these companies should welcome the action plan because it can be seen as a road map for future emission regulations in the region, he says. A spokesperson for the U.S. Edison Electric Institute, which represents investor-owned utilities, says that EEI members do not support mandatory reduction requirements on greenhouse gases, whether they are proposed by an international body or by a regional group. “The technology does not exist to bring [power plant] emissions down to 1990 levels by 2010,” EEI spokesperson Jayne Brady says. Even though the Climate Change Action Plan doesn’t mention any sanctions if the goals aren’t met, the NEG/ECP has a strong record of meeting goals it has set in other agreements, according to environmentalists who follow the group. “Their track record is wonderful in meeting the targets within the timetable they have set out,” says Coon. “We don’t see why they wouldn’t meet these now.” In 1998, the NEG/ECP agreed to cut mercury emissions by half by 2003, and it appears that target will be exceeded. At the August 27 meeting the conference also agreed to further reduce mercury emissions, down by 75% by 2010. A copy of the climate change action plan can be found at www.cmp.ca/press-neg. htm#2001. —CATHERINE M. COONEY

cessing time has dropped from 40 weeks to 24 weeks. As the volume of published papers mushroomed from 149 in 1987 to last year’s 798, the spectrum of topics has expanded to embrace new areas, including microbiology, environmental policy, and green chemistry. And the publication has remained the most prestigious in its field, with a current “impact factor” of 3.5, according to the Institute of Scientific Information, which rates peer-reviewed journals. To cover this broader range of research topics, the size of the Editorial Advisory Board has grown since Glaze took the helm. The number of associate editors grew from 2 to 10, while the ranks of board members rose from 12 to 26. Glaze presided over the opening of the publication’s European office in 2000, and he inaugurated the Magazine Advisory Board for the A-page section this year. Glaze has a genius for inspiring loyalty among his colleagues, says Tom Lehman, who has been an assistant editor for the publication’s manuscript processing office in Chapel Hill since 1997. A number of leading scientists have served on the Editorial Advisory Board for more than a decade, Lehman notes. “Bill knows how to listen carefully to advice and to build consensus. He is a very thoughtful man who has a talent for being critical without being abrasive,” attests Joseph Suflita, director of the University of Oklahoma’s Institute for Energy and the Environment and the MAPCO Professor of Environmental Quality. Suflita has When he's not directing the UNC–CH's Carolina been an Associate Environment Program, or presiding over a U.S. EPA Science Editor since 1990. Advisory Board meeting, Bill Glaze likes to go camping in “Bill’s efforts in places like Boundary Waters Canoe Area Wilderness in launching important Minnesota. He'll have a little more time for such pursuits new directions for in 2003 after he retires from his position as ES&T's Editor. PHOTO COURTESY OF BILL GLAZE

At the end of August, William H. Glaze formally announced his intention to retire from his position as Editor of Environmental Science & Technology. Glaze plans to complete his term at the end of 2002. Glaze became a member of ES&T’s editorial advisory board in 1980, and he was appointed as the publication’s third Editor in 1988. “It was time for a man with enormous vision, [who] would set [the] path to a more internationally oriented research journal of the highest quality,” recalls Russ Christman, Editor of ES&T from 1975 through 1987. Then chair of the University of North Carolina−Chapel Hill’s (UNC−CH) Department of Environmental Sciences & Engineering, Christman recommended Glaze— who at that time was the director of the Environmental Science and Engineering Program at the University of California−Los Angeles— for the job. In his inaugural editorial, Glaze vowed to “continue to press for more rapid turnaround of manuscripts” and to “be receptive to papers from any field of environmental science and technology if a component of the work is of a chemical nature and the quality of the paper is high.” During Glaze’s tenure, the publication’s average manuscript pro-

Government Watch Council for further consideration. In June, EU heads of state singled out the transport sector as a top priority area for sustainable development policy.

Tackling microbes Faced with growing evidence of significant microbial contamination of waters and the potential for emerging pathogenic threats, the U.S. EPA is working to unite the Safe Drinking Water Act and the Clean Water Act to increase protection of public water systems. In the past, programs under the two laws have called for differing indicators of contamination and monitoring approaches, which make it difficult to coordinate efforts aimed at controlling microbial pollution of both surface and drinking water, according to EPA officials. In a draft Strategy for Waterborne Microbial Disease released in late August, the agency highlights septic systems as a primary source of pathogenic contamination, estimating that 10–30% of existing septic systems are failing at any given time. Other sources of water pollution include polluted agricultural runoff, stormwater flows from cities, inadequate sewage treatment, and seepage into groundwater. In all, the U.S. Centers for Disease Control and Prevention estimates that 940,000 cases of illness and up to 900 deaths occur annually as a result of waterborne microbes. To beef up protection of both drinking water and source waters, EPA officials plan to focus on developing ambient water quality criteria and pathogen monitoring protocols, establishing guidelines for more effective septic system operations, analyzing discharge

PHOTODISC

ES&T’s editor to step down after 15 years

Continued on Page 439A

NOVEMBER 1, 2001 / ENVIRONMENTAL SCIENCE & TECHNOLOGY

I

437 A

Environmental M News the journal have combined great vision with hard work and patience. . . . He has recognized what is needed to address the new generation of environmental problems and in so doing promoted and stimulated the work that can meet this challenge,” says Mitchell Small, Heinz Professor of Environmental Engineering at Carnegie-Mellon University and an ES&T Associate Editor since 1996. Glaze’s many changes to the publication have served the needs of both the authors and readers well, adds Ron Hites, distinguished professor of environmental and analytical chemistry at Indiana University

and an ES&T Associate Editor since 1990. In addition to serving as ES&T’s Editor, Glaze is currently the director of the UNC-CH’s Carolina Environmental Program, an interdisciplinary science program that draws faculty from departments throughout the university, including art, anthropology, business, geography, policy, mathematics, and medicine. He is also a professor in the school’s Department of Environmental Sciences and Engineering, a department he previously chaired. Glaze’s research specialty is oxidation processes in water treatment, and he is the author of nearly 200 publications in a

range of disciplines. Currently the chair of the U.S. EPA’s Science Advisory Board, Glaze has chaired the National Academy of Sciences Committee on Drinking Water Additives. He has also earned numerous awards, including the Alexander von Humboldt Foundation’s Senior Science Research Award. To find a replacement for Glaze, the American Chemical Society will form a search committee to canvas the community for nominations, says ACS Special Publications Director Mary Warner. She says the new editor is expected to be announced in mid-2002. —KELLYN S. BETTS

Landfill link to birth defects strengthened Women living near landfills in the United Kingdom are more likely to have smaller babies or babies with congenital defects, according to the largest recorded study of the health effects of living near landfills. Although further research is needed to establish a causal link, the U.K. government is taking the

study seriously, according to the country’s deputy chief medical officer. The study, which was published in August by the British Medical Journal (Br. Med. J. 2001, 323, 363−368), was conducted by a team led by Paul Elliott of the Small Area Health Statistics Unit (SAHSU) at

Imperial College, London. SAHSU researchers surveyed the 8.2 million live births that occurred within a 2-kilometer (km) radius of all 9565 landfill sites that were operational in the United Kingdom between 1982 and 1997 and found that those babies had a 1% higher than expected risk of suffering from con-

TA B L E 1

Adverse birth outcomes and proximity to landfills Risks of congenital anomalies, stillbirths, and low and very low birth weight in populations living within 2 km of a landfill site (all waste types) during operation or after closure compared with those in the reference area (≥2 km from any site).

Birth outcome

Near landfill (