A US and Canadian research team surveying mercury contamination in fish and birds in the northeastern United States and southeastern Canada has identified five "hotspots" where concentrations of the element exceed those established for human or wildlife health.
The team focused on levels of the potent neurotoxin in yellow perch and common loons, but it also took into account contamination in other fish, birds, and mammals. In addition to these hotspots in New England, New York, and Nova Scotia, the researchers found nine "areas of concern" in these regions and in Quebec and New Brunswick. Findings from the team's analysis are summarized in the January 2007 issue of BioScience.
The hotspots are believed to result from complex processes that move atmospherically released mercury through the environment, and from site-specific characteristics such as the high sensitivity of wetlands and forested areas to mercury inputs. Local sources of mercury are also significant. Although mercury is not directly harmful at ambient levels, it is concentrated up to a millionfold and chemically modified in aquatic food chains, resulting in dangerous levels of methylmercury in some wildlife species. Fish consumption advisories responding to mercury contamination exist in all the states and provinces included in the study, and loons are adversely affected by mercury levels they experience.
The hotspots have implications for "cap and trade" approaches being implemented for regulation of emissions from coal-fired electric power stations, which, along with municipal waste incinerators, are major sources of mercury pollution. Cap and trade approaches seek to reduce the total release of mercury but could lead to static or increased emissions in some areas. Greater deposition of mercury near areas that are highly sensitive to the element or that are already affected by it could raise the risk to people and wildlife that consume fish. There is reason to believe, however, that lowering emissions can reduce risk: an analysis of levels of mercury contamination over time in the Merrimack River watershed suggests that lowered emissions reduced mercury levels in biota within a few years.
The 10-member research team was led by David C. Evers of the BioDiversity Research Institute in Gorham, Maine. The study was based on samples collected over four years by the Northeastern Ecosystem Research Cooperative and made use of 7311 observations for seven species. The study report in BioScience is accompanied by an overview article, written by Charles T. Driscoll of Syracuse University and colleagues, that summarizes current knowledge about mercury contamination in the region; the authors conclude that reductions in mercury emissions beyond those currently under way will be needed to eliminate the element as a health risk to humans or to populations of loons.
Donna Royston | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences