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Found 10 records similar to Canadian Total Diet Study - Mercury (Hg) 1998, 2000
This dataset contains 2005 concentrations of total mercury (THg), gaseous elemental mercury (GEM), methylated mercury, dimethyl mercury (DMHg) in the water column of the Canadian Arctic. Mercury in the Arctic is an important environmental and human health issue. The reliance of Northern peoples on traditional foods, such as marine mammals, for subsistence means that they are particularly at risk from mercury exposure. Mercury concentrations on biological organisms have increased since the onset of the industrial age and are controlled by a combination of abiotic factors, food web dynamics and structure, as well as animal behavior.
The determination of the trace element concentrations in food is important for consumer safety. Trace elements are metals that are present in low concentrations in air, water and soil. Thirty-four trace elements are commonly measured in TDS food sample composites. Although mercury and fluoride measurement results are not available on the open data portal, they can be found in the references below.
We set out to examine possible links between climate warming and increases in mercury concentrations ([Hg]) in landlocked Arctic char (S. alpinus) in the High Arctic. Mercury concentrations vary regionally and have remained constant or increased slightly in landlocked char in lakes on Ellesmere Island and Cornwallis Island over a 12-16 year period. This, despite declining industrial mercury emissions in North America. Therefore, we hypothesized that climate warming might increase the input of mercury from catchments through permafrost melt, leading to greater associated body burden of adult char.
Ambient concentrations of speciated mercury (Hg) have been measured at many locations across Canada. Mercury in the atmosphere is measured in three operationally-defined forms - gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate-bound mercury (PBM). Under most conditions, GEM (or Hg0) is the predominant species in the air (~95-99%), while RGM and PBM concentrations are typically two orders of magnitude lower, i.e., <5% of the total atmospheric mercury concentration (Schroeder and Munthe, 1998). Reactive gaseous mercury is thought to consist of compounds such as HgCl2, HgBr2, Hg(OH)2 (Lin and Pehkonen, 1999), although the exact composition is unknown.
Measurements of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate bound mercury on PM2.5 (referred to as PBM2.5) were collected by Environment and Climate Change Canada from August to September 2013 at the Wood Buffalo Environmental Association (WBEA) Air Monitoring Station (AMS) 13 – Fort McKay South, and at WBEA AMS 4 – Buffalo Viewpoint. Monitoring resumed at WBEA AMS 13 in September 2014 with two speciated mercury instruments and is ongoing. One speciated mercury instrument monitors GEM, GOM, and PBM2.5; the second speciated mercury instrument monitors GEM, GOM, and mercury on PM10 (referred to as PBM10). These data are the first atmospheric speciated mercury measurements to be reported in the oil sands region.
Kejimkujik National Park, in Nova Scotia, Canada, is a sensitive region for heavy metal contamination, such as mercury, in part due to long-range atmospheric deposition from global and regional industrial regions. The region is remote from industrial centres, but is downwind of major pollution sources in North America and Canada, and historically had numerous gold mining sites. The region has also experienced anthropogenic acidification from sulphate deposition over the 20th century, which has resulted in limnological conditions favourable for mercury (Hg) methylation within Kejimkujik lakes. Kejimkujik is therefore known to be a hotspot for methylmercury (MeHg) bioaccumulation and biomagnification, with the highest mercury concentrations detected within common loon (Gavia immer) populations across Canada and North America.
Recent and historical deposition of mercury (Hg) are examined over a broad geographic area from southwestern Northwest Territories to Labrador and from the U.S. Northeast to northern Ellesmere Island using dated sediment cores from 50 lakes (18 in midlatitudes (41-50 degrees North), 14 subarctic (51-64 degrees North) and 18 in the Arctic (65-83 degrees North)). Objectives were to quantify latitudinal and longitudinal trends of anthropogenic mercury deposition in eastern and northern North America, to investigate variations in mercury deposition, to examine relationships with lake area, catchment/lake area ratio and sedimentation rates, and to compare results with model predictions. Distinct increases of mercury over time were observed in 76% of Arctic, 86% of subarctic and 100% of midlatitude cores. Subsurface maxima in mercury depositional fluxes were observed in only 28% of midlatitude lakes and 18% of arctic lakes, indicating little recent reduction of inputs.
Environmental quality data from water, fish and sediments in 20 lakes across Canada. Measurements include mercury, methylmercury, physical-chemical parameters such as pH and alkalinity, stable isotopes, fish biological data, nutrients, ions, and metals. The data collection includes sites with a period of record ranging from one year to eight years, starting in 2008. Fish analysed at each site include at least one top predator species and one prey species.
Ambient concentrations of speciated mercury (Hg) have been measured at many locations across Canada. Mercury in the atmosphere is measured in three operationally-defined forms - gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate-bound mercury (PBM). Under most conditions, GEM (or Hg0) is the predominant species in the air (~95-99%), while RGM and PBM concentrations are typically two orders of magnitude lower, i.e., <5% of the total atmospheric mercury concentration. Reactive gaseous mercury is thought to consist of compounds such as HgCl2, HgBr2, Hg(OH)2 although the exact composition is unknown.
Data on fish contaminants is collected across Ontario. Contaminants are chemicals that could be harmful to environment and human health. Toxic contaminants can enter in waterbodies in different ways and can accumulate in fish. Contaminants include: * mercury * polychlorinated biphenyls (PCBs) * dioxins/furans * organochlorine pesticides and others.