lake What are some good things about...?

Mercury? I need some reasons that we should keep mercury from disappearing off the face of the earth for this essay...but I really don't see any good reasons. I know it's used in scientific research, in batteries, and in making pesticides and such, but most of its use has been discontinued. Please help, this is important, and I can't seem to find anything. Also, if you find statistics or testimonies that might be helpful, please send a link. Thank you!there