Mercury poisoning is a type of metal poisoning due to exposure to mercury. Symptoms depend upon the type, dose, method, and duration of exposure. They may include muscle weakness, poor coordination, numbness in the hands and feet, skin rashes, anxiety, memory problems, trouble speaking, trouble hearing, or trouble seeing. High-level exposure to methylmercury is known as Minamata disease. Methylmercury exposure in children may result in acrodynia in which the skin becomes pink and peels. Long-term complications may include kidney problems and decreased intelligence. The effects of long-term low-dose exposure to methylmercury are unclear.
Methylmercury (sometimes methyl mercury) is an organometallic cation with the formula [CH3Hg]+. Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environmental toxicant.
Asubpeeschoseewagong First Nation is an Ojibwe First Nations band government who inhabit northern Kenora in Ontario, Canada. Their landbase is the 4,145 ha English River 21 Indian Reserve. It has a registered population of 1,595 as of October 2019, of which the on-reserve population was 971. As of October 2020, the community had a population of approximately 1,200. They are a signatory to Treaty 3.
The hyporheic zone is the region of sediment and porous space beneath and alongside a stream bed, where there is mixing of shallow groundwater and surface water. The flow dynamics and behavior in this zone is recognized to be important for surface water/groundwater interactions, as well as fish spawning, among other processes. As an innovative urban water management practice, the hyporheic zone can be designed by engineers and actively managed for improvements in both water quality and riparian habitat.
The eddy covariance technique is a key atmospheric measurement technique to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The method analyses high-frequency wind and scalar atmospheric data series, gas, energy, and momentum, which yields values of fluxes of these properties. It is a statistical method used in meteorology and other applications to determine exchange rates of trace gases over natural ecosystems and agricultural fields, and to quantify gas emissions rates from other land and water areas. It is frequently used to estimate momentum, heat, water vapour, carbon dioxide and methane fluxes.
Ontario Minamata disease is a neurological syndrome caused by severe mercury poisoning. It occurred in the Canadian province of Ontario, in 1970, and severely affected two First Nation communities in Northwestern Ontario following consumption of local fish contaminated with mercury, and one First Nation in Southern Ontario due to illegal disposal of industrial chemical waste. The disease was named after the infamous case of severe mercury poisoning in the fishing community of Minamata, Japan, which became known as Minamata disease because it devastated only the residents of the community.
A hydrologic model is a simplification of a real-world system that aids in understanding, predicting, and managing water resources. Both the flow and quality of water are commonly studied using hydrologic models.
The presence of mercury in fish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and young children. Fish and shellfish concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organomercury compound. The element is known to bioaccumulate in humans, so bioaccumulation in seafood carries over into human populations, where it can result in mercury poisoning. Mercury is dangerous to both natural ecosystems and humans because it is a metal known to be highly toxic, especially due to its ability to damage the central nervous system.
Hydrological optimization applies mathematical optimization techniques to water-related problems. These problems may be for surface water, groundwater, or the combination. The work is interdisciplinary, and may be done by hydrologists, civil engineers, environmental engineers, and operations researchers.
The Dryden pulp mill in Dryden, Ontario has been producing one pulp product called Northern Bleached Softwood Kraft (NBSK) since 2007 when it was purchased by Domtar from Weyerhaeuser for about US$520 million. As demand for their products decreased in 2009, hundreds of workers were laid off.
A mire, peatland, or quagmire is a wetland area dominated by living peat-forming plants. Mires arise because of incomplete decomposition of organic matter, usually litter from vegetation, due to water-logging and subsequent anoxia. All types of mires share the common characteristic of being saturated with water, at least seasonally with actively forming peat, while having their own ecosystem. Like coral reefs, mires are unusual landforms that derive mostly from biological rather than physical processes, and can take on characteristic shapes and surface patterning.
Eville Gorham was a Canadian-American scientist whose focus has been understanding the chemistry of fresh waters and the ecology and biogeochemistry of peatlands. In the process, Gorham made a number of practical contributions that included discovering the influence of acid rain in lake acidification, plus the importance of the biological magnification of radioactive fallout isotopes in northern food chains. The former led to legislation and redesign of the power plants of the world to scrub sulfur, and the latter was an early step toward the establishment of an atmospheric nuclear test ban treaty.
Shirley Jean Dreiss (1949–1993) was an American scientist working in the fields of hydrology and hydrogeology. After gaining her PhD from Stanford University, she joined the faculty of the University of California at Santa Cruz, where she became Professor and Chair of the Department of Earth Sciences. She made important contributions to the understanding of water flow through karst aquifers and fluid flow in subduction zones. At the time of her early death in a car accident, she was studying the groundwater system of Mono Lake in California. She was awarded the Birdsall Distinguished Lectureship from the Geological Society of America, which was renamed the Birdsall-Dreiss Distinguished Lectureship after her death.
Kamini Singha is a Professor in the department of Geology and Geological Engineering at the Colorado School of Mines, where she works on questions related to hydrogeology.
Nandita B. Basu is a scientist and professor at the University of Waterloo. Her research is centered on anthropogenic effects on water availability and quality via changes in land use and climate. Basu is recognized for her work on discovering the impact of nutrient legacies and proposed solutions to improving water quality of lakes and coastal zones. She is a member of Robert E. Horton Medal Committee.
Efi Foufoula-Georgiou is a Distinguished Professor in the Civil and Environmental Engineering department at the University of California, Irvine. She is well known for her research on the applications of wavelet analysis in the fields of hydrology and geophysics and her many contributions to academic journals and national committees.
Elsie M. Sunderland is a Canadian toxicologist and environmental scientist and the Gordon McKay Professor of Environmental Chemistry at Harvard University. She studies processes through which human activities increase and modify pollutants in natural ecosystems and living systems.
The Biotron Institute for Experimental Climate Change Research at Western University in London, Ontario is a facility constructed to simulate ecosystems and funded by the Canadian government to study how plants, microbes and insects sense and adjust to climate change. Its biome chambers allow control of temperature, humidity and sunlight so that scientists can simulate climatic zones from rainforests to Arctic tundra. This enables the study environmental science, biotech, materials and biomaterials in realistic environmental conditions while still in a controlled laboratory setting. The Biotron also trains students, including one of Western's winners of The Undergraduate Awards' Global Award.
Mercury contamination in Grassy Narrows, Ontario, Canada—"one of the worst cases of environmental poisoning in Canadian history" is linked to an uncontrolled discharge of between 9,000 kilograms (20,000 lb) and 11,000 kilograms (24,000 lb) of mercury Hg from the Dryden Chemical Company's chloralkali plant, into the headwaters of the 235 km (146 mi)-long Wabigoon River on Lake Wabigoon in the Kenora District of Northwestern Ontario from 1962 until 1970. The Wabigoon River forms a vast river system English River— which includes many lakes and tributaries— together they flow west to the Winnipeg River. Numerous lakes in rivers in the aquatic ecosystem had "extensive mercury contamination" by 1970, leading to the closure of the commercial fishery and some tourism related businesses. The glacial clay of the area is believed to have facilitated the bioaccumulation of mercury in rivers and lakes in the ecosystem. The first major lake downstream from the Dryden mill—Clay Lake, 50 miles (80 km) from the mill, had "extremely high mercury levels in predatory fish" such as the walleye. For generations, the Grassy Narrows First Nation, have "fished Clay Lake and the river downstream." The walleye—the cornerstone of the local fishing-based economy" and the Grassy Narrows' staple food, were unsafe to eat. The semi-remote Grassy Narrows is one of 28 First Nations within the Grand Council Anishinaabe Nation in Treaty No. 3, a sovereign Anishinaabe Nation. The Grassy Narrows reserve, is less than 100 kilometres (62 mi) downstream from the Dryden mill. The Whitedog reserve is several hundred kilometres further downstream. Both First Nations communities were severely affected. For generations, many suffered with symptoms of mercury poisoning, including Minamata disease. Since the mercury poisoning, the Grassy Narrows community "have lived with the consequences of one of the worst cases of environmental poisoning in Canadian history", according to The Lancet. An expert report was released on June 6, 2016, confirming that the Wabigoon River was "still highly contaminated" and that "it can be cleaned safely".
Carol Kendall is a hydrologist known for her research tracking nutrients and contaminants in aquatic ecosystems using isotopic tracers.
