I won't comment on your lack of knowledge regarding the specifics of a small, insignificant UN declaration that the US neglected to sign. After all, child labor, child executions, what's the difference? Yes, that is, as I understand it, the reason why the US failed to sign. They need to be able to execute children in some states.
"As far as breathing clean air, I do agree this is something the US needs to work on. However, I'm not sure the impact this has on freedom or democracy...people are free to live wherever they want, I prefer not near refineries."
You seem to believe that once you pollute, you pollute only that portion, and that it won't move with air and sea currents all across the globe. That's OK. We're all entitled to believe.
We're also free to breathe in the garbage that the world's top polluters spews out. If not, hey, we can always switch planets to live on, can't we? Can't we?