Trace elements in freshwater ecosystems in the Canadian Arctic

2003 ◽  
Vol 107 ◽  
pp. 201-201
Author(s):  
H. Borg
Keyword(s):  
Trace Elements ◽  
Canadian Arctic ◽  
Freshwater Ecosystems

Trace Elements in King Eiders and Common Eiders in the Canadian Arctic

2001 ◽  
Vol 41 (4) ◽  
pp. 491-500 ◽  
Author(s):  
M. Wayland ◽  
H. G. Gilchrist ◽  
D. L. Dickson ◽  
T. Bollinger ◽  
C. James ◽  
...  
Keyword(s):  
Trace Elements ◽  
Canadian Arctic ◽  
Common Eiders

scholarly journals Distribution and risk appraisal of dissolved trace elements in Begnas Lake and Rupa Lake, Gandaki Province, Nepal

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Ramesh Raj Pant ◽  
Kiran Bishwakarma ◽  
Buddha Bahadur Basnet ◽  
Khadka Bahadur Pal ◽  
Laxmi Karki ◽  
...  
Keyword(s):  
Trace Elements ◽  
Health Risk ◽  
Lake Water ◽  
Inductively Coupled Plasma ◽  
Monsoon Season ◽  
Principal Component ◽  
Agricultural Runoff ◽  
Freshwater Ecosystems ◽  
Health Concern ◽  
And Cluster Analysis

AbstractContamination of the trace elements (TEs) in the freshwater ecosystems is becoming a worldwide problem. This study was carried out to investigate the TEs contamination, and their associated health risk in Begnas Lake and Rupa Lake, Gandaki Province, Nepal. A total of 30 water samples were collected from both lakes during the pre-monsoon season in 2016. The samples were analyzed for the TEs including copper (Cu), lead (Pb), zinc (Zn), nickel (Ni), cobalt (Co), chromium (Cr), cadmium (Cd), manganese (Mn), cesium (Cs), and arsenic (As) using inductively coupled plasma mass spectrometry. The results exhibited that the mean concentrations of all the TEs were higher in Rupa Lake as compared to Begnas Lake except Pb. Principal component analysis and cluster analysis revealed that both the geogenic and anthropic sources were the major contributors of TEs in the lake water. Anthropic activities were considered to contribute the TEs like Zn and Mn in lake water mainly via agricultural runoff, while evaluating the risk of TEs on human health all the elements showed HQ < 1 and CR < 10−4 indicating currently very low health risk concerns. In good agreement with above, the water quality index (WQI) of the Begnas Lake and Rupa Lake was 2.67 and 5.66, respectively, specifying the lake water was safe for drinking and public health concern. This appraisal would help the policymakers and concerned stakeholders for the sustainable management of Ramsar listed freshwater lakes in the Himalayas.

Contaminants in common eiders (Somateria mollissima) of the Canadian Arctic

2004 ◽  
Vol 12 (4) ◽  
pp. 197-218 ◽  
Author(s):  
Mark L Mallory ◽  
Birgit M Braune ◽  
Mark Wayland ◽  
H Grant Gilchrist ◽  
D Lynne Dickson
Keyword(s):  
Trace Elements ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Canadian Arctic ◽  
Common Eider ◽  
The Arctic ◽  
Adult Bird ◽  
Somateria Mollissima ◽  
Marine Birds ◽  
Common Eiders

Contamination of the Arctic environment by persistent organic pollutants (POPs) and trace elements remains a key concern for local residents as well as wildlife and resource management organizations. The common eider (Somateria mollissima) is a large marine duck that forms an important component of the diet of many Arctic predators, including humans. Although various studies have been carried out to evaluate the role of a few contaminants thought to be of local concern, efforts to assess contaminant residues in eider tissues have not been comprehensive. In this review, we summarize the available information on POPs and trace elements in common eiders across the Canadian Arctic. With the exception of one adult bird collected near Qikiqtarjuaq, Nunavut, eiders had detectable but low concentrations of most POPs, in some cases markedly lower than European eiders, and in all cases far lower than POP levels found in sympatric marine birds. However, common eiders did have elevated concentrations of many trace elements, noticeably cadmium, selenium, and copper, but these were below levels associated with toxicological risk to marine birds. Although the collective evidence suggests that common eiders of the Canadian Arctic may carry elevated levels of some contaminants, there was no evidence that these levels posed a threat to wildlife health. Key words: common Eider, persistent organic pollutants, trace elements, Arctic Canada.

scholarly journals Mercury in freshwater ecosystems of the Canadian Arctic: Recent advances on its cycling and fate

2015 ◽  
Vol 509-510 ◽  
pp. 41-66 ◽  
Author(s):  
John Chételat ◽  
Marc Amyot ◽  
Paul Arp ◽  
Jules M. Blais ◽  
David Depew ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Freshwater Ecosystems ◽  
Recent Advances

Amount, Sources, and Dissolution of Aerosol Trace Elements in the Canadian Arctic

2021 ◽  
Author(s):  
Joan De Vera ◽  
Priyanka Chandan ◽  
William M. Landing ◽  
Geoff W. Stupple ◽  
Alexandra Steffen ◽  
...  
Keyword(s):  
Trace Elements ◽  
Canadian Arctic

scholarly journals Modern to millennium-old greenhouse gases emitted from freshwater ecosystems of the eastern Canadian Arctic

2015 ◽  
Vol 12 (14) ◽  
pp. 11661-11705 ◽  
Author(s):  
F. Bouchard ◽  
I. Laurion ◽  
V. Preskienis ◽  
D. Fortier ◽  
X. Xu ◽  
...  
Keyword(s):  
Canadian Arctic ◽  
Feedback Mechanism ◽  
Freshwater Ecosystems ◽  
Aquatic Systems ◽  
Emission Rates ◽  
Ice Wedge ◽  
Global Biogeochemical Cycles ◽  
Positive Feedback Mechanism ◽  
Study Sites ◽  
Eastern Canadian Arctic

Abstract. Ponds and lakes are widespread across the rapidly changing permafrost environments. Aquatic systems play an important role in global biogeochemical cycles, especially in greenhouse gas (GHG) exchanges between terrestrial systems and the atmosphere. The source, speciation and emission of carbon released from permafrost landscapes are strongly influenced by local specific conditions rather than general environmental setting. This study reports on GHG ages and emission rates from aquatic systems on Bylot Island in the eastern Canadian Arctic. Dissolved and ebullition gas samples were collected during the summer season from different types of water bodies located in a highly dynamic periglacial valley: polygonal ponds, collapsed ice-wedge trough ponds, and larger lakes overlying unfrozen soils (talik). The results showed strikingly different ages and fluxes depending on aquatic system types. Polygonal ponds were net sinks of dissolved CO2, but variable sources of dissolved CH4. They presented the highest ebullition fluxes, one or two orders of magnitude higher than from other ponds and lakes. Trough ponds appeared as substantial GHG sources, especially when their edges were actively eroding. Both types of ponds produced modern to hundreds of years old (<550 yr BP) GHG, even if trough ponds could contain much older carbon (>2000 yr BP) derived from freshly eroded peat. Lakes had small dissolved and ebullition fluxes, however they released much older GHG, including millennium-old CH4 (up to 3500 yr BP) sampled from lake central areas. Acetoclastic methanogenesis dominated at all study sites and there was minimal, if any, methane oxidation in gas emitted through ebullition. These findings provide new insights on the variable role of permafrost aquatic systems as a positive feedback mechanism on climate.

Microanalytical Identification of a New Zr-Nb-Fe Phase

1990 ◽  
Vol 48 (2) ◽  
pp. 132-133
Author(s):  
O.T. Woo ◽  
G.J.C. Carpenter
Keyword(s):  
Trace Elements ◽  
Cold Rolling ◽  
Proportionality Factor ◽  
Tube Material ◽  
X Ray ◽  
Metal Foils ◽  
Arc Melting ◽  
Intermetallic Particles ◽  
Intermetallic Precipitates ◽  
Cold Worked

To study the influence of trace elements on the corrosion and hydrogen ingress in Zr-2.5 Nb pressure tube material, buttons of this alloy containing up to 0.83 at% Fe were made by arc-melting. The buttons were then annealed at 973 K for three days, furnace cooled, followed by ≈80% cold-rolling. The microstructure of cold-worked Zr-2.5 at% Nb-0.83 at% Fe (Fig. 1) contained both β-Zr and intermetallic precipitates in the α-Zr grains. The particles were 0.1 to 0.7 μm in size, with shapes ranging from spherical to ellipsoidal and often contained faults. β-Zr appeared either roughly spherical or as irregular elongated patches, often extending to several micrometres.The composition of the intermetallic particles seen in Fig. 1 was determined using Van Cappellen’s extrapolation technique for energy dispersive X-ray analysis of thin metal foils. The method was employed to avoid corrections for absorption and fluorescence via the Cliff-Lorimer equation: CA/CB = kAB · IA/IB, where CA and CB are the concentrations by weight of the elements A and B, and IA and IB are the X-ray intensities; kAB is a proportionality factor.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

Trace Elements and Iron in Human Metabolism

1979 ◽  
Vol 7 (6) ◽  
pp. 1330-1331
Author(s):  
E. D. WILLS
Keyword(s):  
Trace Elements ◽  
Human Metabolism
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