Filters: Tags: Mercury (X)768 results (11ms)
Mercury contamination of wildlife populations has been documented widely in recent years as biomonitoring has become an important tool for assessing environmental contamination. Avian eggs provide an ideal assay material for Hg biomonitoring, particularly when the collection of eggs is simplified by using cavity-nesting species that nest in easily monitored nest boxes. However. studies are needed that address the dynamics of how Hg is distributed within eggs, and how Hg is deposited naturally within clutches laid by a single female and among clutches laid by different females occupying the same contaminated environment. We collected 138 eggs from 13 complete clutches of box-nesting wood ducks (Aix sponsa) during...
This is a report of geochemical data from various media collected on Isle Royale, a large island in northeastern Lake Superior. Isle Royale became a national park in 1940 and was designated as a wilderness area in 1976.USGS sampling began in 1996 as part of a larger project on the Midcontinent Rift in the Lake Superior region. Data are given in nine Microsoft Excel spreadsheets. All the data are newly acquired by the USGS.
The following topics are currently covered by the MineralCommodity Summaries: domestic production and uses; U.S. salientstatistics; recycling; import sources; tariff; depletionallowance; government stockpile; events, trends, and issues;world production, reserves, and reserve base; world resources;and substitutes.
To help determine whether Hg had a causal effect on corticosterone, we investigated the impact of experimental Hg intake on the corticosterone stress response in captive juvenile loons. Juveniles were subjected to three different feeding regimes: 0, 0.4 and 1.2 µg Hg (as MeHgCL)/g wet weight (ww) fish. We then measured baseline and 30 min post-solitary confinement stressor corticosterone concentrations. The data set consists of times of blood draws and dietary Hg levels. Blood samples and data set were provided to the senior author for analysis.
Almost all the pictures acquired by Mariner 10 that were used for mapping were obtained during the first encounter: those covering the southeast half of the quadrangle are incoming close-encounter images, and those covering the north-west corner are outoing close-encounter images. At the time the pictures were obtained, the terminator was at about long 7° to 8°, within the eastern part of the quadrangle. A large gap in coverage between in the incoming and outgoing images appears as a northeast-trending diagonal blank strip on the base map. A small part of this gap was filled in the southwestern part of the quadrangle by very poor second-encounter images.
San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and estuarine birds. Sources of mercury to the watershed since 1845 include sediment-associated mercury from mercury mining, mercury losses from gold amalgamation activities in mines of the Sierra Nevada, aerial deposition of mercury from global and regional emissions to air, and the direct discharge of mercury to Bay waters associated with the urbanization and industrialization of the estuary. We assessed historical trends in mercury bioaccumulation by measuring mercury concentrations in feathers of the endangered California Ridgway’s rail (formerly California...
Total mercury, bulk density, percent organic matter, and percent organic carbon measured in permafrost cores collected from 2004 through 2012 from the interior and northern slope of Alaska
The "MasterDB-csv-final2" dataset includes 548 laboratory measurements of sediment total mercury (STHg, nanograms per gram of soil, dry), bulk density (BD, grams per cm3 of soil, dry), percent of soil organic matter (%OM, loss on ignition, LOI), percent of soil organic carbon (%SOC, calculated using the Redfield's number), RHgC (Hg to carbon ratio), and age (YBP) from 13 permafrost cores collected from 2004 to 2012 in the interoir and northern slope of Alaska by trained personnel from the U.S. Geological Survey National Research Program and the National Snow and Ice Data Center in Boulder, Colorado.
Historical deposition of mercury and selected trace elements to high-elevation National Parks in the Western U.S. inferred from lake-sediment cores
Atmospheric deposition of Hg and selected trace elements was reconstructed over the past 150 years using sediment cores collected from nine remote, high-elevation lakes in Rocky Mountain National Park in Colorado and Glacier National Park in Montana. Cores were age dated by 210Pb, and sedimentation rates were determined using the constant rate of supply model. Hg concentrations in most of the cores began to increase around 1900, reaching a peak sometime after 1980. Other trace elements, particularly Pb and Cd, showed similar post-industrial increases in lake sediments, confirming that anthropogenic contaminants are reaching remote areas of the Rocky Mountains via atmospheric transport and deposition. Preindustrial...
Case study of mercury and methylmercury dynamics in a Hg-contaminated municipal wastewater treatment plant
Experimental and theoretical study of combined solvent and steam stripping of 1,2,3,4,5,6-hexachlorocyclohexane (HCH) and mercury from contaminated natural soil
Mercury contamination in the Carson River, Nevada: A preliminary study of the impact of mining wastes
Behavioral effects in mummichog larvae (Fundulus heteroclitus) following embryonic exposure to methylmercury
Production and loss of methylmercury and loss of total mercury from boreal forest catchments containing different types of wetlands