Mercury Contamination Flashcards
(22 cards)
What are the two examples of mass mercury poisonings talked about in class?
Minimata disease, and Poisoning in Iraq
What occurred during the mercury poisonings in Iraq?
There was pesticide coated wheat, and it caused 7000-10,000 deaths, 100,000 people with permanent brain damage and caused silent baby syndrome
What are the natural sources of mercury?
Volcanic eruptions, rocks and soil
What are the anthropogenic sources of mercury?
mining, fossil fuels, batteries, paints, dentistry, computers, cellphones and lighting technologies
In Canada what are the major sources of mercury in the atmosphere and in water?
Atmosphere- electricity (hudroelectric) and coal
Water-effluence and paper and pulp mills
What are the two major parameters that influence Hg. concentration in water?
NOM and pH
What two provinces have not seen a decrease in mercury emissions?
AB and SK
What are the four types of mercury found in the environment?
Hg(0), Hg(1), Hg(2) and organic (methylmercury)
What is the most dangerous type of mercury and why?
methylmercury and it is highly lipophilic and can biomagnify through the food chain
What are the properties of Hg(0)
half life of two years and volatile, can be in sediment, soil or air and can switch into other forms of mercury
What are the properties of Hg(I) and Hg(II)
half life is days, and water soluble
How is methylmercury made?
Bacteria convert HgII to HgCH3 in water
What type of toxicant is mercury?
neuro/nerve toxicant
What are the main target organs?
Brain and kidney
What are some symptoms that occur after chronic exposure to mercury?
permanent brain damage, CNS disorders (memory loss), loss of vision, kidney damage, reproductive damage in developing fetuses, infants and adults
What was a tragedy that occurred in Canada regarding mercury?
Drydan chemicals released 10 000kg of mercury during 1960s into river, lead to premature deaths of the Grassy Narrows First Nations community
What were the results of a study done on mercury testing in Saskatchewan?
DCCO birds were collected from all over Saskatchewan and then it was determined that southern saskatchewan birds had higher levels of mercury in their system
What are the three types of mercury in the atmosphere?
Elemental, divalent and particulate
What is special about elemental mercury in the atmosphere?
makes up 98% of mercury in the air, relatively insoluble
What is special about divalent mercury in the atmosphere?
very soluble, undergoes wet and dry deposition
How does mercury settle into the arctic?
Hg(0) gets into arctic through atmospheric transport, melting ice releases Br and Cl into the atmosphere, Hg precipitates out from atmosphere with Br and Cl, Hg2 released as particulate, creates methyl mercury
What is one of the most concerning effects of having mercury in the arctic?
gets into food sources and the Indigenous populations either have to eat very expensive food or risk being poisoned
