28th December 2020 By 0

canadian mercury science assessment

The bottom graph represents Lake 240 in the Experimental Lakes Area, Ontario, which is remote from emission sources. The main driver of Hg accumulation in biota is the formation and availability of methylmercury in the ecosystem. Levels of mercury in precipitation have also declined at most sites in Canada since the mid-1990s. UNEP, AMAP, 2013. This study evaluated the distribution of mercury in a lighthouse on the Canadian west coast, and the exposure of its keepers and their spouses under two weather conditions. Over the 40 years in Canada, mercury levels in wildlife and fish have shown increasing, stable, or decreasing trends, with variation among monitored species and regions (Figure 9). Mercury accumulations differ from stream to lake sediments, with the latter containing more organic matter, thus enabling Hg methylization and thereby stimulating MeHg uptake by biota. Yellow represents low mercury levels, and as the colour changes from orange to brown, the mercury levels in the fish get progressively higher. The intent of the program was (1) to determine key indicators of environmental quality and human health that are relevant to atmospheric emissions of mercury, (2) to quantify current and past levels for these indicators, and (3) to develop the capacity to predict changes in these indicators associated with changes in levels of atmospheric emissions of mercury or the receiving environment.Note de bas de page1 The geographic focus of the CARA Mercury Science Program was south of the Arctic Circle (60°N latitude). Alberta, Saskatchewan and Manitoba have a higher density of dots than British Columbia and are predominantly yellow with some green dots. In light of our current understanding of mercury in the Canadian environment, where, and to what extent, do we need to continue atmospheric and effects monitoring? However, emissions reductions do not lower mercury levels in the Canadian environment following a linear relationship. Ecotoxicology 20, 1512-1519. Ecosystems in Canada that are especially vulnerable to climate change and mercury contamination include the Arctic, aquatic ecosystems, coastal regions, and wetlands. The top graph represents Wabamun Lake, Alberta, which is located close to mercury emissions from coal-fired power plants. The assessment is the outcome of a partnership between the Clean Air Regulatory Agenda (CARA) Mercury Science Program, led by Environment Canada, and the Canadian Arctic Northern Contaminants Program (NCP), led by Aboriginal Affairs and Northern … The results indicated potential risk to common loon behaviour in 36% of the study lakes and to reproduction in 10%. Mercury emissions differ among provinces, and have decreased in most provinces between 1990 and 2010, with the exception of Alberta and Saskatchewan (Table 1). In comparison, in eastern Canada the total contribution from anthropogenic and other terrestrial emissions from East Asia (20 to 23%) is comparable to the total contribution from the US (15 to 22%). Figure 8: Relative contributions from emissions from individual source regions to net mercury deposition for the Canadian Arctic, British Columbia, Ontario and New Brunswick, Nova Scotia and Prince Edward Island combined for the year 2005 (as estimated by the Global/Regional Atmospheric Heavy Metals model). Although the average exposure of Canadians is low, methylmercury remains a potential public health issue for populations who rely heavily on the consumption of large predatory fish and marine mammals for food, and for potentially susceptible groups including developing fetuses, infants, and children. Other activities such as changes in land use, eutrophication, and climate change likely affect levels of mercury in the Canadian environment, although the relative magnitude of ecosystem responses (including fish mercury concentrations) is not precisely known. The level of emitted mercury starts at 35 000 kg from 1990 to 1992 and shows a strong decline in 1993 to 20 000 kg. Chapter 2: Releases of Mercury Into Air and Water From Anthropogenic Activities in Canada; Chapter 3: Surface Fluxes; Chapter 4: Atmospheric Processes, Transport, Levels, and Trends; Chapter 5: Mercury Fate and Methylation in Terrestrial Upland and Wetland Environments; Chapter 6: Mercury Fate and Methylation in Freshwater Aquatic Ecosystems; Chapter 7: Mercury in the Marine Environment: Processes and Levels; Chapter 8: Influences of Anthropogenic Activities on Mercury Transport, Methylation, and Bioaccumulation; Chapter 9: Mercury Cycling in Ecosystems and the Response to Changes in Anthropogenic Mercury Emissions; Chapter 10: Mercury in Terrestrial and Aquatic Biota Across Canada: Geographic Variation; Chapter 11: Mercury in Terrestrial and Aquatic Biota Across Canada: Temporal Variation; Chapter 12: Health Effects of Mercury in Fish and Wildlife in Canada; Chapter 13: Assessment of Current Mercury Risks to Piscivorous Fish and Wildlife in Canada; Chapter 14: Mercury and Human Health. In 2005, approximately 115 t of mercury was deposited to Canada; approximately 40% of the mercury deposited was from current global anthropogenic emissions and approximately 60% from other global terrestrial (approximately 35%) and oceanic (approximately 25%) emissions. In fact, some mineralized soils and shale rock from Ontario and cinnabar from British Columbia have the highest mercury emissions measured from any soils in the world. There is no data shown for the archipelago of the Northwest Territories and Nunavut. The y (vertical) axis on each graph represents the concentration of mercury in the bird eggs. In comparison with other major mercury-emitting countries, such as the United States and China, Canadian emissions are relatively small. However, omega-3 fatty acids, found in high levels in some fish species, play a pivotal role in certain aspects of neurodevelopment, and may be capable of mitigating or negating some of the adverse effects of prenatal exposure to methylmercury through fish consumption. Mercury is a common pollutant of aquatic ecosystems and it can have a substantial impact on both human and wildlife health. What are the current and forecasted trends in mercury emissions/releases from these activities? As well, the relationship between methylmercury exposure and other diseases is not fully understood. Mercury concentrations in indicator species such as seabirds in the Arctic suggest that levels are continuing to increase in the Arctic marine ecosystem; however, seabirds from other areas show decreases or stable levels, suggesting that those ecosystems are now less impacted by mercury. As a whole, 95% of anthropogenic mercury deposition in Canada is derived from foreign emission sources. Levels of mercury measured in ambient air have ranged between no decline and 26% total decline over various time periods and locations between 1995 and 2011. These workshops led to the development of 7 science questions and sub-questions that capture the information needs of the science and policy communities in Canada. Decreasing emissions of acidic and greenhouse gases are predicted to result in decreased formation of methylmercury and to reduce the bioaccumulation of mercury in wildlife. Several lakes in western (and one in eastern) Northwest Territories are above the estimated lowest observed adverse effect level for fish toxicity, while the remainder fall below these levels. The colours represent risk as follows: The northwestern part of Canada (Yukon) shows teal and green dots in the western and northeastern borders of the territory and yellow dots in the middle. Figure 10: Change in mercury levels in eggs of 3 seabird species from Prince Leopold Island, Nunavut (left: concentration mg g-1 (dry weight)), and in seabird eggs from the Gulf of St. Lawrence (right: concentration mg g-1 (wet weight)). The acidification of aquatic systems that lack properties to buffer acid is long-lasting and may continue for decades after acid emissions controls have been implemented. It was the first assessment to focus exclusively on mercury pollution in the Canadian Arctic. Health effects, in particular neurological impairments, are associated with exposure to high levels of methylmercury. Coordinating author: Anton M. Scheuhammer. The largest unknown is the impact of climate change on the cycling and methylation of mercury. The Government of Canada’s actions to manage risks associated with mercury are summarized in the Risk Management Strategy for Mercury.Note de bas de page3 Canada has signed the United Nations Environment Programme’s Minamata Convention on Mercury (October 2013), which has as its primary goal the protection of human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds. Figure 12 shows the levels of mercury in fish over time from four newly created reservoirs in northern Quebec (Caniapiscau, Robert-Bourassa, Opinaca and LaGrande3). Arrows facing upwards from the forest fire and the industrial emissions refer to Chapter 2: “Releases of Mercury into Air and Water from Anthropogenic Activities in Canada.” Arrows pointing both up and down over the sea ice, the ocean and the land refer to Chapter 3: “Surface Fluxes.” At the top of the image, a long arrow in the sky points to Chapter 4: “Atmospheric Processes, Transport, Levels, and Trends.” Circular arrows near the forest and wetlands refer to Chapter 5: “Mercury Fate and Methylation in Terrestrial Upland and Wetland Environments.”  The number 6 in the middle of the lake refers to Chapter 6: “Mercury Fate and Methylation in Freshwater Aquatic Ecosystems.” Circular arrows over the ocean refer to Chapter 7: “Mercury in the Marine Environment: Processes and Levels.” The number 8 (close to the truck and dam) refers to Chapter 8: “Influences of Anthropogenic Activities on Mercury Transport, Methylation, and Bioaccumulation.” An arrow facing downward from the cloud and sky refers to Chapter 9: “Mercury Cycling in Ecosystems and the Response to Changes in Anthropogenic Mercury Emissions.” Chapter 9 is also highlighted as part of the wetlands and lake images. This delay complicates efforts to determine the response of ecosystems to changes in recent domestic mercury emissions. CurrentlyNote de bas de page13, measurements are in operation by Environment Canada at the following 11 sites: Alert (Nunavut), Whistler (British Columbia), Little Fox Lake (Yukon), Saturna (British Columbia), Ucluelet (British Columbia), Patricia McInnes (Alberta), Flin Flon (Manitoba), Egbert (Ontario), St Anicet (Quebec), Mingan (Quebec), Kejimkujik (Nova Scotia); these sites and type of measurements made are shown in Figure 13a. By contrast, it shows the decline in mercury levels in northern gannet eggs from the Gulf of St. Lawrence over 30 years. These effects have been investigated as part of a unique long-term mercury study, Mercury Experiment to Assess Atmospheric Loadings in Canada and the United States (METAALICUS), conducted at the Experimental Lakes AreaNote de bas de page9 (ELA) in Ontario. Further, bacteria in lake sediments produce methylmercury when little to no oxygen is present (for example, because of eutrophication of lakes). By contrast, lakes contaminated by mercury mining activities, such as Pinchi Lake in central British Columbia, had high mercury levels in fish (trout). The numbers indicate the chapters in which each process is discussed in the assessment report. In fish and wildlife, exposure to methylmercury is associated with impairment of reproduction, growth, and health. Circular arrows close to the land and lake beside the moose, goose and loon refer to Chapter 12: “Health Effects of Mercury in Fish and Wildlife in Canada” and Chapter 13: “Assessment of Current Mercury Risks to Piscivorous Fish and Wildlife in Canada.” The information contained in Chapter 14: “Mercury and Human Health” is indicated next to the two humans in the image. The Canadian Mercury Science Assessment presents science conducted under the Clean Air Regulatory Agenda (CARA) Mercury Science Program, led by Environment Canada, and the Northern Contaminants Program (NCP), led by Aboriginal Affairs and Northern Development Canada as well as scientific work funded by Health Canada, Natural Resources Canada, Fisheries and Oceans Canada, provincial and … Reservoir lakes from Quebec show fish levels exceeding the estimated lowest observed adverse effect level for fish toxicity of lake trout (approximately 1.9 to 2.7 microgram per gram of mercury). Wet deposition of mercury is a good indicator of changes in the mercury load from the atmosphere to the environment. Factors that affect the emission of mercury from soils include soil moisture and temperature, solar radiation, organic matter content, and microbes in the soil. This type of national coordination would include only a few changes to existing protocols and could operate at minimal extra cost. The study examining which mercury species could be responsible for the Minamata poisoning was published Feb. 12th in the journal Environmental Science & Technology. The solid lines represent the levels of mercury predicted in these two lakes when the “best case scenario” for emissions controls is applied to the model starting in 2007. The green solid line starts near zero, rises to 1 mg m-2 yr-1  on the left axis by 1950 and 2 mg m-2 yr-1  by 2007, levelling off near 3 mg m-2 yr-1  by 2050. Other precipitation sites are at Reifel Island (inactive), British Columbia; Fort Vermillion, Crossfield, Esther (all inactive), Henry Kroeger and Genesee, Alberta; Flin Flon, Gillam and Churchill (all inactive), Manitoba; Experimental Lakes Area, Burnt Island, Dorset,  Mississauga, Point Petre (all inactive), Ontario; St. Anicet and Mingan (both inactive), Quebec; St. Andrews (inactive), New Brunswick. The concentration levels are variable over time but show a declining linear trend over the whole time period. Canadian Environmental Quality Guidelines Canadian Environmental Quality Guidelines (CEQGs) provide science-based goals for the quality of aquatic and terrestrial ecosystems.Users will find: chemical-specific guideline fact sheets that summarize the key scientific information and rationale for … Each bar represents a sum of the two source types combined. Lichen and mosses are the only terrestrial vegetation that absorb and accumulate appreciable amounts of mercury, although their use as a good indicator for mercury is uncertain. Elemental mercury is very volatile and is stable in the air, which enables it to travel long distances once emitted. A full list of the time coverage for each site can be found in the full science assessment Chapter 4: Section 4.3. CARA partnered with the Canadian Arctic Northern Contaminants Program (NCP), an Aboriginal Affairs and Northern Development Canada (AANDC) program that conducts scientific research to respond to concerns about human exposure to elevated levels of contaminants, such as mercury, in fish and wildlife species important to the traditional diets of northern Aboriginal people. The integrated model was applied to 5 lake ecosystems in different regions of Canada. Approximately two-thirds of all mercury deposited from East and Central Asian to all regions in Canada is of anthropogenic origin. Site 1 is a large region in west-central Alberta, stretching from the BC border to east of Edmonton, and (in the north-south direction) from north of Calgary to north of Edmonton. Photochemical destruction in lake waters and loss through outflows are the primary mechanisms for removing methylmercury from lakes, which helps to decrease exposure of aquatic organisms and foodwebs. 10.1007/s10646-011-0714-1. Anthropogenic activities such as electricity generation, smelting, cement production/processing, waste incineration, and disposal of mercury-containing products release mercury into the environment. Each world region has a group of four vertical bars representing deposition of mercury to the Canadian Arctic (green bars), British Columbia (blue bars), Ontario (red bars), and the Maritime provinces (New Brunswick (NB), Nova Scotia (NS), and Prince Edward Island (PEI), purple bars). A map of all atmospheric mercury measurements that have been collected in Canada over various time periods between 1995 and 2014 is shown in Figure 13b. Based on results from Environment Canada’s Global/Regional Atmospheric Heavy Metals (GRAHM) model, an estimated 95% of the anthropogenic mercury deposited in Canada comes from sources outside of the country. Furthermore, in Ontario 57% the lakes sampled for walleye and 49% of lakes sampled for northern pike reported mean mercury levels in these fish to be either within or greater than the concentration range for negative effects in fish. At these sites, declines in mercury levels have occurred more quickly than at sites that are impacted mainly by regional and global emissions. The grey areas denote the range of total mercury concentrations in fish from natural lakes in the region. The strongest recovery in the air is in areas close to emission sources such as in Flin Flon (Manitoba), Bratts Lake (Saskatchewan), Reifel Island (British Columbia), Point Petre (Ontario), and St. Andrews (New Brunswick), where mercury levels have declined up to 3.3%Note de bas de page10 per year. The preamble of the Convention, which sets out the context in which the Convention’s obligations should be interpreted, includes several statements that directly affect Canadians, including (but not limited to): Recognizing that mercury is a chemical of global concern owing to its long-range atmospheric transport, its persistence in the environment once anthropogenically introduced, its ability to bioaccumulate in ecosystems and its significant negative effects on human health and the environment…, Noting the particular vulnerabilities of Arctic ecosystems and indigenous communities because of the biomagnification of mercury and contamination of traditional foods, and concerned about indigenous communities more generally with respect to the effects of mercury…. Science of The Total Environment 2019, 693 , ... Assessment of Pb and Cd contaminations in the urban waterway sediments of the Nen River ... A geographical comparison of mercury in seabirds in the eastern Canadian Arctic. More monitoring and research to identify these species is required to entirely understand atmospheric transformation and deposition of mercury. The predicted influences of climate change on the mercury cycle could increase or decrease mercury levels in fish, depending on ecosystem conditions.

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