The above fruits and vegetables are considered the "Dirty Dozen" because they have the tendency to retain a higher level of pesticides and herbicides used by farmers than other types of produce. But no matter where they are from, peaches are the worst culprit and number one on the "Dirty Dozen" list, with a FDA residual chemical rating of 100. This means, of all the produce on the list, peaches retain the highest amount of harmful residual chemicals. For the ratings of other produce on the "Dirty Dozen" list go here: http://www.sustainlane.com/reviews/the-dirty-dozen/W7BMKJ7MHOYAMDYSLJPYYBOJU2SB
Of course, ideally you are buying everything local and organic, but not everyone can afford to do this, so this list is just of recommendations that are particularly important.
Does anyone have any other items on their personal "dirty dozen" list?
I once heard a corollary to this. Apparently, pineapple doesn't take in much pesticide. So if you visit a conventional pineapple farm in hawaii, it will reek of toxic gick: they use more because they are allowed to. They are allowed to because the plant takes up less.