John F DeWild (Former Employee)
Science and Products
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Filter Total Items: 42
Methods for the preparation and analysis of solids and suspended solids for total mercury Methods for the preparation and analysis of solids and suspended solids for total mercury
The methods documented in this report are utilized by the Wisconsin District Mercury Lab for analysis of total mercury in solids (soils and sediments) and suspended solids (isolated on filters). Separate procedures are required for the different sample types. For solids, samples are prepared by room-temperature acid digestion and oxidation with aqua regia. The samples are brought up to...
Authors
Shane Olund, John DeWild, Mark Olson, Michael T. Tate
Mercury loading and methylmercury production and cycling in high-altitude lakes from the Western United States Mercury loading and methylmercury production and cycling in high-altitude lakes from the Western United States
Studies worldwide have shown that mercury (Hg) is a ubiquitous contaminant, reaching even the most remote environments such as high-altitude lakes via atmospheric pathways. However, very few studies have been conducted to assess Hg contamination levels of these systems. We sampled 90 mid-latitude, high-altitude lakes from seven national parks in the western United States during a four...
Authors
David Krabbenhoft, Mark Olson, John DeWild, David Clow, Robert Striegl, Mark Dornblaser, Peter C. Van Metre
Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99 Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99
We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early 1999. MeHg levels in the outflow...
Authors
M. Brigham, D. P. Krabbenhoft, M.L. Olson, J.F. DeWild
Atmospheric mercury deposition during the last 270 years: A glacial ice core record of natural and anthropogenic sources Atmospheric mercury deposition during the last 270 years: A glacial ice core record of natural and anthropogenic sources
Mercury (Hg) contamination of aquatic ecosystems and subsequent methylmercury bioaccumulation are significant environmental problems of global extent. At regional to global scales, the primary mechanism of Hg contamination is atmospheric Hg transport. Thus, a better understanding of the long-term history of atmospheric Hg cycling and quantification of the sources is critical for...
Authors
Paul Schuster, David Krabbenhoft, David Naftz, L. Cecil, Mark Olson, John DeWild, David Susong, Jaromy Green, Michael Abbott
Mercury, methylmercury, and other water-quality data from flood-control impoundments and natural waters of the Red River of the North Basin, Minnesota, 1997-99 Mercury, methylmercury, and other water-quality data from flood-control impoundments and natural waters of the Red River of the North Basin, Minnesota, 1997-99
It is now well documented that impoundment of natural waters, with inundation of terrestrial area, results in enhanced conversion of inorganic mercury to methylmercury, a form that is toxic and bioaccumulates to a greater extent than inorganic mercury. Concentrations of mercury, methylmercury, and other water-quality constituents are reported from water sampled from flood-control...
Authors
Mark Brigham, Mark Olson, John DeWild
Radon-222 concentrations in ground water and soil gas on Indian reservations in Wisconsin Radon-222 concentrations in ground water and soil gas on Indian reservations in Wisconsin
The weighted average radon-222 concentration of indoor air in homes located on Wisconsin Indian Reservations is 5.8 picocuries per liter, which exceeds the U.S. Environmental Protection Agency action limit of 4 picocuries per liter. Ground water is the principle source of drinking water on Wisconsin Indian Reservations and generally accounts for about 5 percent of the total indoor air...
Authors
John DeWild, James Krohelski
Science and Products
Filter Total Items: 14
No Result Found
Filter Total Items: 42
Methods for the preparation and analysis of solids and suspended solids for total mercury Methods for the preparation and analysis of solids and suspended solids for total mercury
The methods documented in this report are utilized by the Wisconsin District Mercury Lab for analysis of total mercury in solids (soils and sediments) and suspended solids (isolated on filters). Separate procedures are required for the different sample types. For solids, samples are prepared by room-temperature acid digestion and oxidation with aqua regia. The samples are brought up to...
Authors
Shane Olund, John DeWild, Mark Olson, Michael T. Tate
Mercury loading and methylmercury production and cycling in high-altitude lakes from the Western United States Mercury loading and methylmercury production and cycling in high-altitude lakes from the Western United States
Studies worldwide have shown that mercury (Hg) is a ubiquitous contaminant, reaching even the most remote environments such as high-altitude lakes via atmospheric pathways. However, very few studies have been conducted to assess Hg contamination levels of these systems. We sampled 90 mid-latitude, high-altitude lakes from seven national parks in the western United States during a four...
Authors
David Krabbenhoft, Mark Olson, John DeWild, David Clow, Robert Striegl, Mark Dornblaser, Peter C. Van Metre
Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99 Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99
We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early 1999. MeHg levels in the outflow...
Authors
M. Brigham, D. P. Krabbenhoft, M.L. Olson, J.F. DeWild
Atmospheric mercury deposition during the last 270 years: A glacial ice core record of natural and anthropogenic sources Atmospheric mercury deposition during the last 270 years: A glacial ice core record of natural and anthropogenic sources
Mercury (Hg) contamination of aquatic ecosystems and subsequent methylmercury bioaccumulation are significant environmental problems of global extent. At regional to global scales, the primary mechanism of Hg contamination is atmospheric Hg transport. Thus, a better understanding of the long-term history of atmospheric Hg cycling and quantification of the sources is critical for...
Authors
Paul Schuster, David Krabbenhoft, David Naftz, L. Cecil, Mark Olson, John DeWild, David Susong, Jaromy Green, Michael Abbott
Mercury, methylmercury, and other water-quality data from flood-control impoundments and natural waters of the Red River of the North Basin, Minnesota, 1997-99 Mercury, methylmercury, and other water-quality data from flood-control impoundments and natural waters of the Red River of the North Basin, Minnesota, 1997-99
It is now well documented that impoundment of natural waters, with inundation of terrestrial area, results in enhanced conversion of inorganic mercury to methylmercury, a form that is toxic and bioaccumulates to a greater extent than inorganic mercury. Concentrations of mercury, methylmercury, and other water-quality constituents are reported from water sampled from flood-control...
Authors
Mark Brigham, Mark Olson, John DeWild
Radon-222 concentrations in ground water and soil gas on Indian reservations in Wisconsin Radon-222 concentrations in ground water and soil gas on Indian reservations in Wisconsin
The weighted average radon-222 concentration of indoor air in homes located on Wisconsin Indian Reservations is 5.8 picocuries per liter, which exceeds the U.S. Environmental Protection Agency action limit of 4 picocuries per liter. Ground water is the principle source of drinking water on Wisconsin Indian Reservations and generally accounts for about 5 percent of the total indoor air...
Authors
John DeWild, James Krohelski