Veiga & Baker established that the main pathways of Hg to humans living in close proximity to ASGM sites are the “inhalation of Hg vapor from amalgam burning and gold melting, and the ingestion of methyl mercury from dietary sources, especially fish.”3 Additionally, according to Bank, the chemical forms by which people are exposed to mercury are: • Inorganic compounds (Hg combined with chloride, hydroxide, sulfide, dissolved organic matter (DOM); or other noncarbon species) • Elemental (or metallic) mercury, and • Organic compounds (Hg combined with methyl, ethyl, or other carbon species).9 It seems that the risk of contamination by mercury through water consumption is very low according to Veiga and Baker. These authors claim that because the stability and brief residence time of MeHg in aquatic systems (MeHg is readily consumed by microorganisms at the base of the food chain), its concentration in natural ecosystems is extremely low. Even further, they say, “if people are drinking unfiltered water full of suspended particles, it seems that Hg is the least health problem related to this.” 3 Bank, as well as many other authors, agrees that the major impact on human health is due to inhalation of vapor mercury and MeHg intake through fish.9 However, this author states that mercury toxicity on human health depends on different factors such as the route of exposure, the dose consumed, and the age of the person. Additionally, citing other authors, Bank claims that,
b. [3.3] Is there more mercury in the phytoplankton at the base of the food chain or in the fish at the top? (2pts)
If mercury biomagnifies, in which of the organisms would you expect to find the highest mercury levels in a lake with mercury contamination?
The Wabigoon – English River in Ontario has been contaminated with mercury for about 40 years now and the government has not approached this issue that affects most of the people of Grassy Narrows First Nation. A majority of the community has mercury poisoning, which could be fatal. Additionally, residents are forced to continue to consume contaminated food. In the 1970s, the government let the river to naturally recover itself and said that it would be better than any attempts to clean it, however, it has only gotten worse. Now, the government says that they do not want to attempt to clean the water until they are completely sure that it will not make the situation worse. Recently, scientists have suggested several solutions that have been successful in the past, but it is still unknown as to when the government will clean the water.
The very chemicals that are used to treat our water to kills deadly toxins are the same chemicals that can pose health problems when digested for a period of time (EPA 2013). For instance, excessive consumption of fluoride over a lifetime may lead to increased likelihood of bone fractures in adults, and tooth enamel pits in young children. Lead consumption leads to physical and mental development in children and mercury consumption leads to kidney damage. (Birmingham Water Works).
While nitrates are one of the major contaminants in the area, San Joaquin Valley residents face drinking water pollution from many other sources including arsenic, coliform bacteria, and pesticides. Arsenic is a naturally occurring semi-metal element that is found in different types of rocks. While arsenic primarily occurs naturally, human activities impact the amount of arsenic in groundwater. Arsenic is not only toxic at high concentrations, but also harmful after prolonged exposure at moderately elevated levels. California recognizes arsenic as a human carcinogen and believes prolonged exposure to the element to be associated with various cancers, including skin, bladder, kidney, lung, and liver cancers. A study in Maine found a connection between water contaminated
Mercury is another toxic pollutant that may be found in the tailings and in the surface and ground water supplies of the Silver Bow Creek area. While mercury is
3. The EPA “safe dose” for mercury is 1,100 ppb (parts per billion) for women in their child-bearing years, as mercury levels above this value may impair neurological development in the fetus. Which
For instance, certain seafoods are known to have high concentrations of mercury. The same can be found inside of certain dental fillings, such as silver fillings or mercury amalgrams.
Karen Nelson, Neuroepidemiology Branch, National Institute of Neurological Disorders and Stroke; and Margaret Bauman, Children’s Neurology Service, Harvard Medical School conducted a study on neuropathology of mercury toxicity. Nelson and Bauman asserted ethylmercury lacks the active transport mechanism across the blood-brain barrier that other found available to methylmercury however; they provided no evidence to support this assertion. The L system is the major transport
Mercury is an element that can be found in our environment through air, water and soil. Being exposed to constant levels of mercury may be detrimental to one’s overall health since it can impact the nervous, digestive and immune systems of human (WHO). In 1960, the demand of Mercury (Hg) increased significantly as it was needed in many commercial and medical practices, despite its high toxicity levels (dwivedi). Thus, the increase in mercury consumption was due to industrialization. Mercury should be gaining increased medical concerns as it can impact the lives of several classes of society. In Canada, it is found that the vast majority of marine mammals contain methylmercury (MeHg) (Laird). Methylmercury is highly more lethal than Mercury
As already stated, many other locations around the world are affected by mercury poisoning and contamination. For example, Canada and Japan have an extensive history of mercury poisoning, including neurologic symptoms and contaminated fish. These studies have has been documented since the 1950’s in these locations. In fact, the contamination became so problematic the Ontario health department formed a task force on organic mercury in 1972. Further, recent protesting throughout Toronto has asked for Canada to address the contamination of mercury. Findings revealed levels of mercury exceeding those of international standards and included the highest recorded mercury contamination among in the western part of the world. (CITE 6)
Once released into the environment, mercury is free to be taken up by plants and animals but is not toxic unless transformed through bacterial or chemical processes into its organic form, the most famous of which is methylmercury [6], [8], [10] Methylmercury impacts several critical organ systems and particularly toxic to the development of the fetus [11]. It also bioaccumulates in living organisms, which leads to higher levels of methylmercury with each increasing trophic level [10], [12], [13]
The Department of Public Health issued a guide for women and children to use at supermarket fish counters to educate them about the healthiest seafood choices. With the help of the Department of Public Health and their issued guide for women and children, it informs women who are pregnant to only eat one meal a month of Connecticut fish because of the mercury found in them. According to the For Women, Children Especially, Some Fish Better Than Others newspaper article, “Fish that should not be eaten at all by anyone include Wyassup Lake in North Stonington, Dodge Pond in East Lyme and Versailles and Papermill ponds in Sprague that are located in twelve waterways around the state that are polluted with harmful chemicals” (Benson, 2).
The health hazards for humans who come in contact with contaminants from exposure to polluted water can have long term effects on the body causing possible organ failure and death. Contaminants and chemicals such lead and mercury can bring about many minor illnesses ranging from nausea, lung irritation, skin rash, vomiting, and dizziness, to the major diseases that include cancer, liver and kidney damage, disorders of the nervous system, damage to the immune system, birth defects and even death.
The CTBC claims that e-waste accounts for approximately 40 percent of these three toxins that end up landfills, noting that "just 1/70th of a teaspoon of mercury can contaminate 20 acres of a lake, making the fish unfit to eat."