Pesquisas avaliam contaminação por mercúrio no Canadá e nos EUA

BioScience, Volume 57, Issue 1

A contaminação por mercúrio é um tema cuidadosamente estudado no Canadá e nos EUA, considerando os seu imensos riscos à biodiversidade. Por Henrique Cortez, do EcoDebate.

De acordo com o MCT, Ministério da Ciência e Tecnologia, a contaminação por mercúrio em áreas de garimpo de ouro na Amazônia chega a exceder em até 40 vezes os níveis estabelecidos pela Organização Mundial de Saúde (OMS), segundo constatou pesquisa realizada pelo Centro de Tecnologia Mineral (Cetem), instituição vinculada ao Ministério da Ciência e Tecnologia (MCT). A mineração artesanal na região amazônica é responsável por quase 50% da produção brasileira de ouro.

Sabemos do problema, conhecemos os seus riscos ambientais e seus danos à saúde, mas estamos muito longe de, efetivamente, pesquisar a real dimensão do problema e, mais longe ainda, de erradicar a contaminação por mercúrio.

Como sugestão, estamos indicando a leitura de dois textos científicos(“Mercury Contamination in Forest and Freshwater Ecosystems in the Northeastern United States” e “Biological Mercury Hotspots in the Northeastern United States and Southeastern Canada“), publicados na revista BioScience, que demonstram a preocupação em pesquisar o tema.

O acesso ao conteúdo integral dos artigos é livre, bastando clicar nos links indicados.

Mercury Contamination in Forest and Freshwater Ecosystems in the Northeastern United States

CHARLES T. DRISCOLL, YOUNG-JI HAN, CELIA Y. CHEN, DAVID C. EVERS, KATHLEEN FALLON LAMBERT, THOMAS M. HOLSEN, NEIL C. KAMMAN, and RONALD K. MUNSON
BioScience, Article: pp. 17–28
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Eastern North America receives elevated atmospheric mercury deposition from a combination of local, regional, and global sources. Anthropogenic emissions originate largely from electric utilities, incinerators, and industrial processes. The mercury species in these emissions have variable atmospheric residence times, which influence their atmospheric transport and deposition patterns. Forested regions with a prevalence of wetlands and of unproductive surface waters promote high concentrations of mercury in freshwater biota and thus are particularly sensitive to mercury deposition. Through fish consumption, humans and wildlife are exposed to methylmercury, which markedly bioaccumulates up the freshwater food chain. Average mercury concentrations in yellow perch fillets exceed the Environmental Protection Agency’s human health criterion across the region, and mercury concentrations are high enough in piscivorous wildlife to cause adverse behavioral, physiological, and reproductive effects. Initiatives are under way to decrease mercury emissions from electric utilities in the United States by roughly 70%.

Keywords: atmospheric deposition, bioaccumulation, methylmercury, mercury contamination, northeastern United States

DOI: 10.1641/B570106

Charles T. Driscoll (e-mail: ctdrisco@syr.edu) works in the Civil and Environmental Engineering Department, Syracuse University, Syracuse, NY 13244.

Young-Ji Han, a postdoctoral research fellow with the Hubbard Brook Research Foundation in New Hampshire when this article was prepared, can be reached at the Department of Environmental Science, Kangwon National University, Chuncheon, Kangwon-do, Korea.
Celia Y. Chen works in the Department of Biological Sciences, Dartmouth College, Hanover, NH 03755.
David C. Evers is with the BioDiversity Research Institute, Gorham, ME 04038.
Kathleen Fallon Lambert consults for the Hubbard Brook Research Foundation from an office in Woodstock, VT 05091.
Thomas M. Holsen is with the Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY 13699.
Neil C. Kamman works at the Vermont Department of Environmental Conservation, Water Quality Division, Waterbury, VT 05671.
Ronald K. Munson is with Tetra Tech, Inc., Mars, PA 16046.

Biological Mercury Hotspots in the Northeastern United States and Southeastern Canada

DAVID C. EVERS, YOUNG-JI HAN, CHARLES T. DRISCOLL, NEIL C. KAMMAN, M. WING GOODALE, KATHLEEN FALLON LAMBERT, THOMAS M. HOLSEN, CELIA Y. CHEN, THOMAS A. CLAIR, and THOMAS BUTLER
BioScience, Article: pp. 29–43
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Biological mercury (Hg) hotspots were identified in the northeastern United States and southeastern Canada using a data set of biotic Hg concentrations. Eight layers representing three major taxa and more than 7300 observations were used to locate five biological Hg hotspots and nine areas of concern. The yellow perch and common loon were chosen as indicator species for the human and ecological effects of Hg, respectively. Biological Hg hotspots receive elevated atmospheric Hg deposition, have high landscape sensitivity, and/or experience large reservoir fluctuations. In the Merrimack River watershed, local Hg emissions are linked to elevated local deposition and high Hg concentrations in biota. Time series data for this region suggest that reductions in Hg emissions from local sources can lead to rapid reductions of Hg in biota. An enhanced Hg monitoring network is needed to further document areas of high deposition, biological hotspots, and the response to emissions reductions and other mitigation strategies.

Keywords: biological mercury hotspots, mercury sources, common loon, mercury monitoring, yellow perch

DOI: 10.1641/B570107

David C. Evers (e-mail: david_evers@briloon.org) work at the BioDiversity Research Institute, Gorham, ME 04038.
M. Wing Goodale work at the BioDiversity Research Institute, Gorham, ME 04038.
Young-Ji Han is with the Hubbard Brook Research Foundation, Hanover, NH 03755; she can be reached at the Department of Environmental Science, Kangwon National University, Chuncheon, Kangwon-do, Korea.
Charles T. Driscoll is with the Civil and Environmental Engineering Department, Syracuse University, Syracuse, NY 13244.
Neil C. Kamman works in the Vermont Department of Environmental Conservation, Water Quality Division, Waterbury, VT 05671.
Kathleen Fallon Lambert is with the Hubbard Brook Research Foundation.
Thomas M. Holsen works at the Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY 13676.
Celia Y. Chen is with the Department of Biological Sciences, Dartmouth College, Hanover, NH 03755.
Thomas A. Clair works for Environment Canada, Sackville, New Brunswick, E4L 1G6, Canada.
Thomas Butler works at the Institute of Ecosystem Studies and Cornell University, Ithaca, NY 14853.

[ O conteúdo produzido pelo EcoDebate é “Copyleft”, podendo ser copiado e/ou distribuído, desde que seja dado crédito ao autor e ao Ecodebate, como fonte original da informação.][EcoDebate, 05/09/2008]