Within the last billion years on earth, how many tons of excrement has achieved escape velocity?

I think gbaikie deserves some sort of recognition as having raised one of the most unusual serious questions ever asked on the internet (with Jacob getting special mention as well...should he want it).

Well, there's the stuff that's been "dumped" there deliberately, a side-effect of human spaceflight, as Jacob notes. Other than that--as "it" deteriorates, would it be possible for it to rise naturally from the surface as an aerosol and eventually escape?

Or, perhaps less likely, have there been impacts in the last billion years that may have thrown such matter into space?

And finally the most pressing question of all: is there any way we can get it back?