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Full-Text Articles in Physical Sciences and Mathematics
Evidence Does Not Support A Role For Gallic Acid In Phragmites Australis Invasion Success, Jeffrey D. Weidenhamer, Mei Li, Joshua Allman, Robert G. Bergosh, Mason Posner
Evidence Does Not Support A Role For Gallic Acid In Phragmites Australis Invasion Success, Jeffrey D. Weidenhamer, Mei Li, Joshua Allman, Robert G. Bergosh, Mason Posner
Jeffrey D. Weidenhamer
Gallic acid has been reported to be responsible for the invasive success of nonnative genotypes of Phragmites australis in North America. We have been unable to confirm previous reports of persistent high concentrations of gallic acid in the rhizosphere of invasive P. australis, and of high concentrations of gallic acid and gallotannins in P. australis rhizomes. The half-life of gallic acid in nonsterile P. australis soil was measured by aqueous extraction of soils and found to be less than 1 day at added concentrations up to 10,000 mu g g(-1). Furthermore, extraction of P. australis soil collected in North Carolina …
Bioavailability Of Cadmium In Inexpensive Jewelry, Jeffrey D. Weidenhamer, Jennifer Miller, Daphne Guinn, Janna Pearson
Bioavailability Of Cadmium In Inexpensive Jewelry, Jeffrey D. Weidenhamer, Jennifer Miller, Daphne Guinn, Janna Pearson
Jeffrey D. Weidenhamer
BACKGROUND: High cadmium (Cd) concentrations have recently been found in some inexpensive jewelry. In response, the US Consumer Product Safety Commission (CPSC) has issued five recalls of children’s jewelry products for Cd contamination. However, there is no formal standard for Cd in jewelry and few data exist regarding potential exposures. OBJECTIVES: We evaluated the bioavailability of Cd in 86 components of 57 jewelry items found to contain high levels of Cd (>10,000 ppm) by X-ray fluorescence (XRF), using extractions which simulate mouthing or swallowing of jewelry items. METHODS: Jewelry was screened for Cd content by XRF. Bioavailability was measured …
Evidence Of Recycling Of Lead Battery Waste Into Highly Leaded Jewelry, Jeffrey D. Weidenhamer, Micheal L. Clement
Evidence Of Recycling Of Lead Battery Waste Into Highly Leaded Jewelry, Jeffrey D. Weidenhamer, Micheal L. Clement
Jeffrey D. Weidenhamer
Inexpensive highly leaded jewelry, much of it imported from China, remains widely available in the United States. The source materials for these items are unknown. Due to the low cost of much of this trinket jewelry, it seems likely that scrap materials may be used in their manufacture. Thirty-nine jewelry items previously determined to contain 90% or more lead by weight were analyzed for antimony content. The average antimony content of these thirty-nine items was 3.0%. The range of antimony content in the samples was from 0.3% to 6.2% antimony by weight, with twenty-seven of the samples in the range …
Leaded Electronic Waste Is A Possible Material For Lead-Contaminated Jewelry, Jeffrey D. Weidenhamer, Michael L. Clement
Leaded Electronic Waste Is A Possible Material For Lead-Contaminated Jewelry, Jeffrey D. Weidenhamer, Michael L. Clement
Jeffrey D. Weidenhamer
Highly leaded jewelry, often imported from China, remains widely available in the United States. Leaded electronic waste is exported from the United States to several Asian countries where solder is recovered and circuit boards are stripped of parts in small workshops. To assess whether electronic waste is being recycled into the jewelry, lead, tin and copper content of highly leaded jewelry samples were determined by atomic absorption spectrometry. Sixteen jewelry items previously determined to contain 20–80% lead by weight were analyzed. Samples were digested in nitric acid for analysis of lead and copper, and in aqua regia for analysis of …