1 / 15

Water Pollution

Water Pollution. Part 2 Mercury. D24. I can … explain how the accumulation of mercury, phosphates and nitrates affects the quality of water and the organisms that live in rivers, lakes and oceans. What is Mercury?. Mercury is a well-known environmental pollutant.

shea-nash
Download Presentation

Water Pollution

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Water Pollution Part 2 Mercury

  2. D24 I can … explain how the accumulation of mercury, phosphates and nitrates affects the quality of water and the organisms that live in rivers, lakes and oceans.

  3. What is Mercury? • Mercury is a well-known environmental pollutant. • While it has many uses, it has serious health effects when released into the environment. • Human health can be affected when people consume animals exposed to mercury.

  4. What sorts of organisms contain Mercury? • Fish are often found to be contaminated with mercury. • Fish can be found in streams, wetlands, reservoirs and lakes can have high levels of mercury in their flesh. • A majority of states have issued fish consumption advisories.

  5. So, how are fish in these lakes becoming contaminated? • Mercury contamination can be found even in fish from remote lakes. • How are these fish becoming so contaminated when the atmospheric levels of mercury is so low?

  6. Mercury undergoes Bioaccumulation • What does this mean? • This is the process by which organisms build up mercury in their bodies. They take in mercury more quickly than they can get rid of it. • Over time, the organism will accumulate mercury, until it can even reach toxic levels.

  7. It also undergoes Biomagnification Mercury increases at each step in a food chain, because each organism takes the mercury from the organism that it eats which has taken in the mercury from the organisms that it ate … and so on … and so on

  8. Biomagnification • The highest levels of mercury are found at the highest levels of the food chain. • Bigger fish, older fish, and carnivorous fish will have the highest levels of mercury. • And, the mercury concentrates in the muscles of the fish, which is the part that humans eat

  9. Mercury Poisoning • Mild cases have the following symptoms: • Reduction in motor skills • Dulled sense of touch, taste and sight • Pregnant women should avoid ingesting mercury at all costs, as unborn babies are very sensitive to mercury poisoning.

  10. Effects of more advanced mercury poisoning • Deterioration of the nervous system • Impaired hearing, speech, vision • Difficulty walking • Tremors, or involuntary muscle movements • Corrosion of skin and mucous membranes • Difficulty with chewing and swallowing

  11. How does mercury enter the food chain? • Bacteria take in inorganic mercury and convert it to a different form called methyl-mercury • This form is more toxic and is harder for organisms to eliminate • The bacteria release the methyl-mercury, where it enters the food chain by being absorbed by plankton

  12. Sources of Mercury • Natural Sources • Volcanoes • Natural mercury deposits • Release from the oceans • Human sources • Coal combustion • Waste incineration • Metal processing

  13. Current levels of Mercury • Human activities have doubled or tripled mercury levels. • This also is increasing by about 1.5% per year

  14. What can we do to help? • If emissions could be reduced by 5%, it would take 8 years for changes in fish concentrations would be observed, but the changes would be small. • Due to the bioaccumulation and biomagnification of mercury, this problem will take a long time to be solved.

  15. Reference Krabbenhoft, D. P., & Rickert, D. A. (2008). Retrieved from U.S. Geological Survey website: http://pubs.usgs.gov/fs/1995/fs216-95

More Related