Mercury in the Ocean - San Diego Miramar Collegefaculty.sdmiramar.edu/faculty/sdccd/alowe...highest...
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RESEARCH POSTER PRESENTATION DESIGN © 2015 www.PosterPresentations.com Mercury is a major issue that should not be taken lightly. Mercury poisoning in humans includes serious physical and mental symptoms ranging from gum disease to nerve loss in the hands and face. Mercury comes from natural sources such as volcanoes but the reason it is is such a problem now is because humans are contributing a lot of mercury to the environment. Over the past 150 years, humans have doubled the amount of mercury in the atmosphere which eventually gets deposited into our oceans when it rains. Mercury is not a problem alone, though, only methylmercury, which is the highly toxic form, poses health risks to humans and animals. The mercury conversion process happens when microbes in the ocean convert mercury to methylmercury. This toxic form of mercury gets passed up the food chain where it can be found in high amounts in large fish that are popular to eat, such as tuna. Abstract Where Mercury Comes From Mercury wouldn’t pose such a health risk to humans if it weren’t converted to methylmercury. The conversion process starts in bacteria living in seafloor sediments. Here, microbes use anaerobic respiration because there isn’t much oxygen in the sediment. Instead of relying on oxygen, microbes use sulfide for respiration and excrete sulfide into the water as a waste product. If the seawater within the sediment contains mercury, the fish will produce methylmercury. Methylmercury is the organic form that is highly toxic to the nervous system. Most forms of mercury can’t pass through a cell membrane but sulfide helps mercury get into cells. When positively charged mercury ions (Hg*2) - the most common form of mercury in the ocean - meet negatively charged sulfide, the two bond. This forms the compound mercury sulfide (HgS) which can pass into microbial cells. Once inside the cells, mercury gets methylated and the cells release methylmercury into the open water where it is ingested by phytoplankton. From there it gets passed up the food chain where it can ultimately be found at the top in the highest concentrations (Winner, 2010). How Mercury Gets into Fish The biggest source of mercury pollution is the burning of fossil fuels, which releases 160 tons of mercury into the air in the United States alone. From there, rainfall washes the mercury into the ocean (Winner, 2010). Oceans contain about 60,000-80,000 tons of mercury pollution. Shallow ocean waters have tripled in mercury concentration since the industrial revolution and total mercury in the ocean has increased by 10% since pre industrial times. (Targeted News Service, 2018). It is likely that fish contain three times more mercury than 150 years ago (www.nsf.gov , 8/06/14). Large fish contain more mercury than smaller fish because they live longer in the ocean and have more time to accumulate high levels of mercury in their bodies (Stibich, 5/4/19). Mercury in the World’s Oceans Effects of Mercury Poisoning in Humans Mercury is highly toxic to the nervous system. When ingested by humans and animals it can cause serious harm (usgs.gov, 5/9/2019). Symptoms of mercury poisoning in humans include anxiety, depression, irritability, memory problems, numbness, pathologic shyness and tremors. Advanced mercury poisoning in adults can result in hearing and speech difficulties, lack of coordination, muscle weakness, nerve loss in the hands and face, trouble walking and vision changes (Healthline.com, 12/13/18). In infants and children, symptoms can be much worse depending on how much mercury is consumed. Symptoms include late development in walking and talking and decreased performance on neurological tests. Mercury poisoning can also result in what is known as “mad hatter syndrome” with symptoms of laughing, crying, dramatic mood swings, insomnia, and the inability to concentrate. Kidney toxicity leads to protein in the urine and acute renal failure. Gastrointestinal symptoms include nausea, vomiting, diarrhea and colitis (inflammation of the colon lining). Skin toxicity causes chelitis (cracked corners of the mouth), gum disease and excessive salivation. What is more worrying is that after stopped exposure to mercury, it takes up to 18 years to clear a half dose of mercury from the human body (Hyman, 2017). Avoiding Mercury Poisoning and Hope for a less Contaminated Future Eating large amounts of seafood over a long period of time increases the risk of mercury poisoning. The Food and Drug Administration recommends that women who are pregnant or nursing, women who may become pregnant, and young children completely avoid eating shark, swordfish, king mackerel, and tilefish. It is recommended to eat no more than 6 ounces per week of white albacore tuna and to eat no more than 12 ounces per week of any other fish or shellfish to reduce the risk of mercury poisoning. (Johnson, 2004). On a lighter note, in areas where efforts have been made to cut down on mercury emissions, the amounts of mercury in the water have gone way down, quickly. Also, the move to use “clean” coal is helping to reduce the amount of mercury going into the ocean. Clean coal has a low sulfur content and getting rid of the sulfur in turn gets rid of most of the mercury (Winner, 2010). Hopefully the future will see mercury emissions go down so we don’t have to worry about being poisoned by the fish we like to eat. Mercury is emitted by natural sources such as volcanoes, geothermal springs, geological deposits and the ocean. Human-related sources of mercury emissions include coal combustion, waste incineration and mining. Over the past 150 years, human activities have more than doubled the amounts of mercury in the atmosphere (usgs.gov, 5/9/2019). Mercury advisories cover more than 10 million acres of lakes and more than 400,000 miles of streams. Mercury contamination is global and widespread and is found in areas with no nearby sources of the compound. This is because mercury emissions disperse widely into the atmosphere before being deposited to the Earth’s surface. Mercury concentration is the highest in urban areas with high population densities. Sources of mercury in these areas are wastewater- treatment plants, waste incinerators, crematoriums, steel mills, cement kilns, and disposal sites for batteries, thermometers and fluorescent bulbs (Wentz, 2014). By Cole Kappel Mercury in the Ocean In 1971, a chemical plant dumped methylmercury into the water supply of a village in Minamata Bay, Japan. This picture depicts a resident of the village, Tomoko, born blind, deaf and with deformed limbs being bathed by her mother (www.ocregister.com , 10/19/08). (www.starkist.com , 9/22/17) It is recommended to eat no more than 6 ounces of white albacore tuna per week (Johnson, 2004). Large fish contain more mercury than smaller fish because they live longer in the ocean and have more time to accumulate high levels of mercury in their bodies (Stibich, 5/4/19). (brewminate.com, 12/28/17) The biggest source of mercury pollution is the burning of fossil fuels, which releases 160 tons of mercury into the air in the United States alone. (Winner, 2010). Works Cited Brigham, Mark E. “Mercury in the Environment.” Mercury, USGS, 2014, www.usgs.gov/mission-areas/water-resources/science/mercury?qt- science_center_objects=0#qt-science_center_objects. Dybas, Cheryl. “Mercury in the World's Oceans: On the Rise.” NSF, 6 Aug. 2014, www.nsf.gov/news/news_summ.jsp?cntn_id=132171. Hyman , Mark. “Mercury: Get This Heavy-Metal Poison Out of Your Body.” Dr. Mark Hyman, 22 Sept. 2017, drhyman.com/blog/2010/05/20/mercury-get-this-poison- out-of-your-body/. Johnson, Christine L,M.D., F.A.A.P. (2004). Mercury in the environment: Sources, toxicities, and prevention of exposure. Pediatric Annals, 33(7), 437-42. Retrieved from http://libraryaccess.sdmiramar.edu:8080/login?url=https://search- proquest-com.libraryacc ess.sdmiramar.edu/docview/217556343?accountid=38871 Mercury in the world's oceans: On the rise. (2018, Feb 24). Targeted News Service Retrieved from http://libraryaccess.sdmiramar.edu:8080/login?url=https://search -proquest- com.libraryaccess.sdmiramar.edu/docview/1551604864?accountid=38871 Murrell, Daniel. “Understanding Mercury Poisoning.” Healthline, Healthline Media, 13 Dec. 2018, www.healthline.com/health/mercury-poisoning. Stibich, Mark. “Concerned About Mercury? Here Are the Fish to Enjoy and Those to Avoid.” Verywell Fit, Verywellfit, 4 May 2019, www.verywellfit.com/ the-best- types-of-fish-for-health-2223830. Wentz, Dennis A., et al. The Quality of Our Nation's Water: Mercury in the Nation's Streams– Levels, Trends, and Implications. U.S. Department of the Interior, U.S. Geological Survey, 2014. Winner, Cherie. “How Does Toxic Mercury Get into Fish?” Woods Hole Oceanographic Institution, 1 Oct. 2010, www .whoi.edu/oceanus/feature/how-does-toxic-mercury-get-into-fish/. Winner, C. (2010, Dec). How does mercury get into fish? Oceanus, 48, 23- 26. Retrieved from http://libraryaccess.sdmiramar.edu:8080/login?url=https://search- proquest- com.libraryaccess.sdmiramar.edu/docview/1418410131?accountid= 38871 Illustrations Cited Cambridge University. “Industrial Revolution Left a Damaging Psychological 'Imprint' on Today's Populations of England and Wales.” We're Never Far from Where We Were, 28 Dec. 2017, brewminate.com/industrial-revolution-left-a -damaging-psychological-imprint-on-todays-populations-of-england- and- wales/. Larsen, Peter. “The Most Memorable Life Magazine Photos in One Book.” Orange CountyRegister, Orange County Register, 19 Oct. 2008, www .ocregister.com/2008/10/19/the-most-memorable-life-magazine -photos-in-one-book/. Starkist. “Chunk Light Tuna in Water.” StarKist, 22 Sept. 2017, starkist.com/products/chunk-light-tuna-in-water-can. Stibich, Mark. “Concerned About Mercury? Here Are the Fish to Enjoy and Those to Avoid.” Verywell Fit, Verywellfit, 4 May 2019, www.verywellfit.com/ the-best- types-of-fish-for-health-2223830.
Transcript of Mercury in the Ocean - San Diego Miramar Collegefaculty.sdmiramar.edu/faculty/sdccd/alowe...highest...
RESEARCH POSTER PRESENTATION DESIGN © 2015
www.PosterPresentations.com
Mercury is a major issue that should not be taken lightly. Mercury poisoning in humans includes serious physical and mental symptoms ranging from gum disease to nerve loss in the hands and face. Mercury comes from natural sources such as volcanoes but the reason it is is such a problem now is because humans are contributing a lot of mercury to the environment. Over the past 150 years, humans have doubled the amount of mercury in the atmosphere which eventually gets deposited into our oceans when it rains. Mercury is not a problem alone, though, only methylmercury, which is the highly toxic form, poses health risks to humans and animals. The mercury conversion process happens when microbes in the ocean convert mercury to methylmercury. This toxic form of mercury gets passed up the food chain where it can be found in high amounts in large fish that are popular to eat, such as tuna.
Abstract
Where Mercury Comes From
Mercury wouldn’t pose such a health risk to humans if it weren’t converted to methylmercury. The conversion process starts in bacteria living in seafloor sediments. Here, microbes use anaerobic respiration because there isn’t much oxygen in the sediment. Instead of relying on oxygen, microbes use sulfide for respiration and excrete sulfide into the water as a waste product. If the seawater within the sediment contains mercury, the fish will produce methylmercury. Methylmercury is the organic form that is highly toxic to the nervous system. Most forms of mercury can’t pass through a cell membrane but sulfide helps mercury get into cells. When positively charged mercury ions (Hg*2) - the most common form of mercury in the ocean - meet negatively charged sulfide, the two bond. This forms the compound mercury sulfide (HgS) which can pass into microbial cells. Once inside the cells, mercury gets methylated and the cells release methylmercury into the open water where it is ingested by phytoplankton. From there it gets passed up the food chain where it can ultimately be found at the top in the highest concentrations (Winner, 2010).
How Mercury Gets into Fish The biggest source of mercury pollution is the burning of fossil fuels, which releases 160 tons of mercury into the air in the United States alone. From there, rainfall washes the mercury into the ocean (Winner, 2010). Oceans contain about 60,000-80,000 tons of mercury pollution. Shallow ocean waters have tripled in mercury concentration since the industrial revolution and total mercury in the ocean has increased by 10% since pre industrial times. (Targeted News Service, 2018). It is likely that fish contain three times more mercury than 150 years ago (www.nsf.gov, 8/06/14). Large fish contain more mercury than smaller fish because they live longer in the ocean and have more time to accumulate high levels of mercury in their bodies (Stibich, 5/4/19).
Mercury in the World’s Oceans
Effects of Mercury Poisoning in Humans
Mercury is highly toxic to the nervous system. When ingested by humans and animals it can cause serious harm (usgs.gov, 5/9/2019). Symptoms of mercury poisoning in humans include anxiety, depression, irritability, memory problems, numbness, pathologic shyness and tremors. Advanced mercury poisoning in adults can result in hearing and speech difficulties, lack of coordination, muscle weakness, nerve loss in the hands and face, trouble walking and vision changes (Healthline.com, 12/13/18). In infants and children, symptoms can be much worse depending on how much mercury is consumed. Symptoms include late development in walking and talking and decreased performance on neurological tests. Mercury poisoning can also result in what is known as “mad hatter syndrome” with symptoms of laughing, crying, dramatic mood swings, insomnia, and the inability to concentrate. Kidney toxicity leads to protein in the urine and acute renal failure. Gastrointestinal symptoms include nausea, vomiting, diarrhea and colitis (inflammation of the colon lining). Skin toxicity causes chelitis (cracked corners of the mouth), gum disease and excessive salivation. What is more worrying is that after stopped exposure to mercury, it takes up to 18 years to clear a half dose of mercury from the human body (Hyman, 2017).
Avoiding Mercury Poisoning and Hope for a less Contaminated Future
Eating large amounts of seafood over a long period of time increases the risk of mercury poisoning. The Food and Drug Administrationrecommends that women who are pregnant or nursing, women who maybecome pregnant, and young children completely avoid eating shark, swordfish, king mackerel, and tilefish. It is recommended to eat no more than 6 ounces per week of white albacore tuna and to eat no more than 12 ounces per week of any other fish or shellfish to reduce the risk of mercury poisoning. (Johnson, 2004). On a lighter note, in areas where efforts have been made to cut down on mercury emissions, the amounts of mercury in the water have gone way down, quickly. Also, the move to use “clean” coal is helping to reduce the amount of mercury going into the ocean. Clean coal has a low sulfur content and getting rid of the sulfur in turn gets rid of most of the mercury (Winner, 2010). Hopefully the future will see mercury emissions go down so we don’t have to worry about being poisoned by the fish we like to eat.
Mercury is emitted by natural sources such as volcanoes, geothermal springs, geological deposits and the ocean. Human-related sources of mercury emissions include coal combustion, waste incineration and mining. Over the past 150 years, human activities have more than doubled the amounts of mercury in the atmosphere (usgs.gov, 5/9/2019). Mercury advisories cover more than 10 million acres of lakes and more than 400,000 miles of streams. Mercury contamination is global and widespread and is found in areas with no nearby sources of the compound. This is because mercury emissions disperse widely into the atmosphere before being deposited to the Earth’s surface. Mercury concentration is the highest in urban areas with high population densities. Sources of mercury in these areas are wastewater- treatment plants, waste incinerators, crematoriums, steel mills, cement kilns, and disposal sites for batteries, thermometers and fluorescent bulbs (Wentz, 2014).
By Cole KappelMercury in the Ocean
In 1971, a chemical plant dumped methylmercury into the water supply of a village in Minamata Bay, Japan. This picture depicts a resident of the village, Tomoko, born blind, deaf and with deformed limbs being bathed by her mother (www.ocregister.com, 10/19/08).
(www.starkist.com, 9/22/17) It isrecommended to eat no more than 6 ounces ofwhite albacore tuna per week (Johnson, 2004).
Large fish contain more mercury than smaller fish because they live longer in the ocean and have more time to accumulate high levels of
mercury in their bodies (Stibich, 5/4/19).
(brewminate.com, 12/28/17) The biggest source of mercury pollution is the burning of fossil fuels, which releases 160 tons of mercury into the air in the United States alone.
(Winner, 2010).
Works CitedBrigham, Mark E. “Mercury in the Environment.” Mercury, USGS, 2014,
www.usgs.gov/mission-areas/water-resources/science/mercury?qt-science_center_objects=0#qt-science_center_objects.
Dybas, Cheryl. “Mercury in the World's Oceans: On the Rise.” NSF, 6 Aug.2014,www.nsf.gov/news/news_summ.jsp?cntn_id=132171.
Hyman , Mark. “Mercury: Get This Heavy-Metal Poison Out of Your Body.” Dr. Mark Hyman, 22 Sept. 2017, drhyman.com/blog/2010/05/20/mercury-get-this-poison-out-of-your-body/.
Johnson, Christine L,M.D., F.A.A.P. (2004). Mercury in the environment: Sources, toxicities, and prevention of exposure. Pediatric Annals, 33(7), 437-42. Retrieved from http://libraryaccess.sdmiramar.edu:8080/login?url=https://search-proquest-com.libraryaccess.sdmiramar.edu/docview/217556343?accountid=38871
Mercury in the world's oceans: On the rise. (2018, Feb 24). Targeted NewsService Retrieved from http://libraryaccess.sdmiramar.edu:8080/login?url=https://search-proquest-com.libraryaccess.sdmiramar.edu/docview/1551604864?accountid=38871
Murrell, Daniel. “Understanding Mercury Poisoning.” Healthline, Healthline Media, 13 Dec. 2018, www.healthline.com/health/mercury-poisoning.
Stibich, Mark. “Concerned About Mercury? Here Are the Fish to Enjoy and Those to Avoid.” Verywell Fit, Verywellfit, 4 May 2019,www.verywellfit.com/the-best- types-of-fish-for-health-2223830.
Wentz, Dennis A., et al. The Quality of Our Nation's Water: Mercury in theNation's Streams–Levels, Trends, and Implications. U.S. Department of the Interior, U.S. Geological Survey, 2014.
Winner, Cherie. “How Does Toxic Mercury Get into Fish?” Woods Hole Oceanographic Institution, 1 Oct. 2010, www.whoi.edu/oceanus/feature/how-does-toxic-mercury-get-into-fish/.
Winner, C. (2010, Dec). How does mercury get into fish? Oceanus, 48, 23-26. Retrieved from http://libraryaccess.sdmiramar.edu:8080/login?url=https://search-proquest-com.libraryaccess.sdmiramar.edu/docview/1418410131?accountid=38871
Illustrations CitedCambridge University. “Industrial Revolution Left a Damaging
Psychological 'Imprint' on Today's Populations of England and Wales.” We're Never Far from WhereWe Were, 28 Dec. 2017, brewminate.com/industrial-revolution-left-a-damaging-psychological-imprint-on-todays-populations-of-england-and-wales/.
Larsen, Peter. “The Most Memorable Life Magazine Photos in One Book.”OrangeCountyRegister, Orange County Register, 19 Oct. 2008, www.ocregister.com/2008/10/19/the-most-memorable-life-magazine-photos-in-one-book/.
Starkist. “Chunk Light Tuna in Water.” StarKist, 22 Sept. 2017, starkist.com/products/chunk-light-tuna-in-water-can.
Stibich, Mark. “Concerned About Mercury? Here Are the Fish to Enjoy andThose to Avoid.” Verywell Fit, Verywellfit, 4 May 2019, www.verywellfit.com/the-best-types-of-fish-for-health-2223830.
