You have to realize plants have a big problem, just as you or I if we were out in the jungle and we see a lion, we can run away, but what do plants do?  When a bug comes along and wants to eat that plant, what does it do?  Well, it can't run away and so if it's going to survive an attack from a bug, a human, from anything, it has to protect itself.  What does it do?  It uses pesticides. Plants are full of pesticide.  If they weren't they wouldn't exist.  They'd all have been eaten!  There would be nothing left. And so some of these pesticides are perfectly safe, we've been eating them for years, there's no problem.  But some of them are not quite so safe.