Selenium is a chemical that affects the water stream

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Selenium is a chemical that affects the water stream. There are many chemicals that affect the Earth and it's organisms.a. Visit the Environment Protection Agency's website (epa.gov) and find "Chemicals and Toxics" under Environmental Topics to answer the following questions.

i.Choose at least three chemicals at random. Read about each chemical and explain where it is found and how it affects organisms, air, etc.

ii.Create one master list of all the chemicals you researched and categorize them as either human caused or caused by natural events. Which list is longer, human-caused or nature-caused?

iii.Does human impact play a role in the creation of these chemicals? What actions could hu-mans take to decrease the development of these chemicals? What actions might you specifi-cally take to decrease the development of these chemicals?

b. Go to the website www.pubmed.gov and find the article: Mercury and Selenium in Fish of Fountain Creek, Colorado (USA): Possible Sources and Implications. Download the pdf file of the article to your computer. This article is free. If you are asked to pay money for the article then you have done some-thing wrong and should start over.

i.What is causing the high selenium content in Fountain Creek, Colorado? Name two of the fish collected in order to conduct the scientists' research (you may use their common names or their scientific names).

ii. Name one of the fish that was found with the highest selenium content found? Did the sele-nium (Se) content increase or decrease as the water flowed downstream? What about the mercury (Hg) content?iii.Based on this article that you found on www.pubmed.gov, describe what you learned from two of the figures and/or tables.