Manganese is a naturally occurring mineral comprising approximately 0.1 % of the earth’s crust. It is found in many salts and mineral complexes that are widely distributed in rocks, soils and on the floors of lakes and oceans. For aquatic systems the manganous (Mn2+) and manganic (Mn4+) oxidation states of manganese are the most significant. The element dissolves in the water of some underground aquifers when it is present in the geological layers within the aquifer. As a result, since groundwater contains manganese, it is present in well water distribution systems and drinking water supplies. A typical concentration for manganese found in groundwater is 2 mg/L (2 ppm). Manganese is generally present in natural surface waters, in dissolved or suspended form, at much lower concentrations than in groundwater (below 0.05 mg/L). The fact that it is more prevalent in groundwater supplies rather than in drinking water sources is attributed to the reducing conditions that exist in the subsurface. Some lakes and reservoirs also contain high manganese concentrations due to acidic pollution.
1.2 Impact on water quality
The U.S. Environmental Protection Agency (EPA) has regulated a maximum contaminant level for manganese, not because this mineral is considered to be a health hazard, but essentially due to aesthetic concerns such as staining effects, taste and discoloration. The recommended concentration limit for manganese in drinking water is 0.05 mg/L, set as the aesthetic objective (Health Canada, 2009). The presence of manganese in drinking water at high levels is undesirable, as it is associated with a series of problems. At concentrations higher than 0.15 mg/L, manganese stains plumbing fixtures and laundry. In addition, it causes und...
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...anganese levels include hypertension, psychiatric illnesses, mental confusion, impaired memory, loss of appetite and neurological problems. Well water containing a high manganese content can lead to excessive manganese intake and increased bacterial growth (Blaurock-Busch, 2002). Except for one isolated incident, which still remains unclear, manganese intoxication due to drinking water has not been recorded. In 1941 in Japan, the cause of a disease similar to encephalitis was attributed to well water with a high manganese concentration of 14 mg/L. However, other metals like zinc were also present in excessive concentrations and it was never confirmed whether the high level of manganese was, on its own, responsible for causing the disease. Regarding the acceptable daily intake, no adverse health effects were noted in humans with the following daily manganese intakes:
Dental amalgam is a commonly used restorative material that contains mercury and is of particular concern due to the potential detrimental effects it has on both the environment and humans (Chin et al, 2000). Some of the generated amalgam-contaminated sludge is released into the sewage system. Extracted or missing teeth that contain amalgam fillings as well as amalgam-contaminated waste, like trituration capsules and cotton rolls are expelled along with solid waste and often incinerated as well (Chin et al, 2000). The negative ramifications associated with dental mercury usage is on large a result of poor management of dental amalgam waste (Chin et al, 2000). To address these concerns, health professionals have attempted to implement programs that promote positive environmental action. For example, the DCW (Dentists for Cleaner Water) program involves the installation of dental amalgam separators with further measures put in place to decrease dental amalgam waste entering the water system by 95% (Adavb.net, 2016). To reduce waste, dentists are encouraged to slightly modify their usual habits such as purchasing in bulk, limiting single use items and setting printers for double-sided and greyscale printing. It is important for health professionals to be aware of the potential ecological and public health risks associated with
things up; reaching greater mass. Thus, if anything spreads in social media, it’s a big news. It’s a medium where everyone is a content creator, a publisher. Social media comes first to rescue, in certain cases, before the law can do anything - or when the law has failed to anything. As much as this is true for present issues and incidents, the social media is also revealing the information about Komagata Maru journey, a historic racism incident. Some sources are showing reality of racism against the Indians in which some are writing and making their own views, some sources shows opposition and some shows favour.
Maus is a graphic memoir by Art Spiegelman, about a father, Vladek, survivor of the Holocaust and a son, Arty, who wants to know what was it like living during the Holocaust era. During the holocaust years, Vladek was advised by a rabbi that his tattooed number will bring him luck. Throughout the story, he continues to personify the luck his number represents by being persistent and hardworking. Despite suffering starvation, thirst, and not feeling well, Vladek continues to remain humble by helping his fellow inmates. Many years passed after the war ended, Vladek was portrayed as this conservative man, but there was a reason behind that mask. Vladek did not want people to step over him like he was stepped on before; he wanted to teach Arty
Based off of the human continuum scale, Mali should be placed as an empire because of their accomplishments as an empire during the ruling of Mansa Musa. According to source 2, sheet 2 (B), Mansa Musa was the greatest Muslim king of the Sahel. Complexity in the empire was shown in Mali’s history when Mansa Musa moved the capital to Timbuktu, allowing Mali to be in complete control of all important trade routes. This resulted in the economy and trade prospering tremendously, especially in their salt and gold trade. All of the prosperity in the empire was due to the king, Mansa Musa, who led his empire to be the richest and wealthiest empire Africa had ever seen. Moving the capital to Timbuktu and ruling the trade routes wasn’t the only impact Mansa Musa had on Mali.
This article is about an experiment done to try to see if Aluminum can cause resistance in potatoes to a disease. Aluminum is commonly found in arid soils which accounts for 35% of all farmable on earth. The aluminum (specifically Al3+) targets the roots of the plants and causes stunted plant growth and abnormal root formation. THis causes stresses in the plant which could lead to cross resistance. This immunity has led to some plants to develop cross resistance to diseases. THis has happened before in the plant, an example is the fact that ozone induces resistance to the tobacco mosaic virus in tobacco plants. This phenomenon is what is being tested for in potato plants. Potato plants will be subjected to infections from Phytophthora
A huge fascination of arsenic started in the 19th century when people got word of a province in southeastern Austria where people ate arsenic. Women would eat arsenic to help gain weight and fix their complexion to look more beautiful and men would eat arsenic because they believed it helped them breath easier when they were climbing high up in the mountains. One doctor by the name of Dr. Robert Craig MacLagan, was particularly interested in this and visited the town to see for himself what was really occurring. He observed the people and tested their urine to prove that they have been indeed ingesting arsenic. He wrote about the things he witnessed in the Edinburgh Medical Journal. The men in the town would eat 6 grains/dose at least twice a week, sometimes eating it on their bread or just drinking it with their water. As a result many Victorians began self-medicating themselves with arsenic.
Scientists say, that the levels of these are too low to do any damage to our bodies. The Environmental Protection Agency, however, states that arsenic and lead have increased IQ deficit risks and cancer (12 Reasons).... ... middle of paper ... ...
Recently the concerns of women around their equality in society has become a hotly debated topic in the public spot light. Much of the debate concerns women and the ingrained sexism that permeates most cultures. Many women's activists feel that this ingrained sexism has widened the gap between men and women in a political, social, and economic sense. And for the most part they do have strong evidence to support these claims. Women have suffered through millennia of male dominated societies where treatment of women has been, and in some cases still is, inhuman. Women are treated like subhuman creatures that have only exist to be used for procreate and to be subjugated by men for household use. It has only been very recently that women have become recognized as equals in the eyes of men. Equals in the sense that they have the same political and social rights as males. While the situation has improved, women still have to deal with a male oriented world. Often women in the workplace are thought of as inferior and as a liability. This can be due to concerns about maternity leave, or women with poor leadership skills. But also in part it is due because of the patriarchy that controls all aspects and dynamics of the culture, family, politics, and economy. Even developed countries like The United Kingdom, United States, Germany, and France, could be classified as a patriarchies. These countries may not agree with this notion because of expansive, but not complete changes, that have gradually equalized women in society. However, there are developed countries that openly express a patriarchy and have enacted little societal changes to bring equality to women. Japan is one such country, and t...
Heavy metals are characteristic parts of the Earth's covering. They can't be debased or destroyed. To a little degree they enter our body by means of drinking water, food and air. As follow components, some substantial metals (e.g. copper, selenium, zinc) are crucial to look after the metabolism of the human body. At higher concentrations they can accelerate poisoning. Devastating poisoning of metals arise from drinking-water pollution (e.g. lead channels), high surrounding air fixations close to emission sources, or through food chain.
Mali is a landlocked country in North West Africa. It is bordered with Algeria to the South, Niger to the East, Burkina Faso and Cote d’Ivoire to the south and Senegal and Mauritania to the west. Modern day Mali is nowhere close to what it was at its peak in the 1300s. It was a flourishing empire, and one of the three empires that controlled trans-Saharan trade. It covered twice the size of modern day France, meaning around 1,500,000 kilometres square. However during the Scramble of Africa, France seized control of Mali making it a part of French Sudan. After the independence from the French, French Sudan became the Federation of Mali. However Senegal left, leaving Sudan occupying Mali. After a coup in 1991, Mali became an independent country. Now however, Mali is 1,240,000 Kilometres Square with a Gross Domestic Product of just 631 dollars per capita, compared to 43,185 dollars per capita in the United Arab Emirates. Mali has a population of around 14 million people. The southern part of Mali is more populated because it features the Niger and Senegal rivers. Mali’s prominent natural resource is gold. Actually it is the third largest producer of gold in all of Africa, but however the country is still poor. One of the arising problems in Mali, is humanitarian rights. The Tuareg rebellion, and a political upheaval generated by a March military coup led to a deterioration in respect to the human rights in Mali. After the occupation of the North, the respect to the human rights in Mali fell drastically forcing about 400,000 northern residents being displaced. Several armed groups, took control of territories in the North, and abused civilians. This abuse includes sexual abuse, looting and pillaging houses, and setting executions, rec...
When the water comes into contact with the pyrite, the chemical reactions that take place causes the water to increase in pH which will dissolve heavy metals which stay in solution. However, when the pH levels reach a certain stage, the iron can then precipitate out, coating sediments with the characteristic yellow, red or orange colourings (D.E.P. 2, 2002; U.S.G.S.; U.S.E.P.A., 2002). The rate that A.M.D. advances is also influenced by the presence of certain bacteria (Doyle; U.S.G.S). A.M.D that has dissolved heavy metals such as copper, lead and mercury can contaminate ground and surface water. Especially at risk are mines that are located above the water table (Keller, 2000; D.E.P. 2, 2002). The sources of water that get polluted can be surface water that permeates into the mine, shallow ground water flowing through the mine or any water that comes into contact with the waste tailings produced by mines.
There are three main perspectives of metaphysics in philosophy, which “examine the nature of reality”, defined in Friedenberg and Silverman (2015). This studies the issue of mind-body, asking questions, such as, “What is the mind? Is it physical? Does the body necessarily need a mind?” As well as “What is consciousness? Does it exist in everything? “The mind-body problem addresses how physiological or mental properties are related to physical properties”.
Metalloids are elements that share properties of both nonmetals and metals. They usually share physical properties with metals and chemical properties with nonmetals. Although they are not as good at conducting electricity and heat as metals, metalloids can still act as semiconductors; they can act as conductors in the right condition. Metalloids are solid at room temperature and are semiconductive. Being semiconductive means that, in the right conditions, metalloids can conduct heat and electricity. Because of their metallic physical properties, metalloids most commonly appear to be lustrous and brittle. Metalloids’ nonmetallic chemical properties allow metalloids to form alloys with metals and be weakly acidic. Metal-metalloid alloys such as pewter and Babbitt can be used in porcelain and electrical motors alongside other uses.
Metals possess many unique fundamental properties that make them an ideal material for use in a diverse range of applications. Many common place things know today are made from metals; bridges, utensils, vehicles of all modes of transport, contain some form of metal or metallic compound. Properties such as high tensile strength, high fracture toughness, malleability and availability are just some of the many advantages associated with metals. Metals, accompanied by their many compounds and alloys, similar properties, high and low corrosion levels, and affects, whether negative or positive, are a grand force to be reckoned with.
Materialism is very complex, and can be defined on a number of different platforms. There is no one definite definition of materialism, meaning there is an ambiguity surrounding the construct of materialism. According to Kasser et al. (2004), consumers develop a materialistic value orientation at times when they experience feelings of insecurity, and from exposure to materialistic models and values. When the psychological needs of individuals are not met, they tend to move toward materialism in order to help them feel better about themselves, and reduce feelings of insecurity and self-doubt through the consumption of materialistic items.