This one of my three primary reasons why I am prefer to grow my own meds; I know what I got, where it came from, and who did what with it before I smoked it.

You never know what the hell someone put that smoke through before you got it, what they grew it with, for all you know it was pumped full of all kinds of chemicals and transported over in a gas tank before some crazy freak and his pit bull masturbated all over it.