Grappling with Grapes

I really like grapes, and I always eat them when they're out.  I really need to remember to buy some organic ones and to stop eating non-organic ones.  After all, they are on the dirty dozen list.  So here's my latest problem with grapes: yesterday I was picking at some grapes that were out for a meeting.  A co-worker walks up and says "mm...grapes" he looks at the top of the box (I didn't) and says "oh, wash these well they're from Chile"  "Right, I said, probably full of pesticides..."  He starts washing his handful... "well, DDT.."    As he walks away munching on his handful of grapes, I thought  didn't we ban that in the 70s or something?   I was right.  http://en.wikipedia.org/wiki/DDT. Well I was really freaked out, because we did ban it Chile hadn't?  I thought why would the US let us eat produce that had been sprayed with DDT? And why would the US do business with a country that was using DDT, how hypocritical don't they know that eventually it affects the entire ecosystem, not just Chile's immediate environment?
Well my freak out lasted until I did some googling.  It turns out Chile banned DDT in 1984 (as many countries have since the 70s).  They probably did it once I was born in Feb. 1984 - "oh that girl will one day grow up to hate pesticides, especially DDT...let's get rid of it now"  Ok maybe not.  but anyway, it's been gone for a while.  
So then why are imported grapes on the dirty dozen?  Why not US grapes?  
http://organic.lovetoknow.com/Dirty_Dozen_Organic_Foods
That article explains it.  Domestic grapes are still bad, but not AS BAD as imported.  Makes you wonder what the other countries are using!  Funny that cherries in the US are worse than the cherries that are imported.  I Wonder why.  Once I figured this out..i'll let you know!