You may never know the purity of your food, but you do know that eating fresh ripe whole food is the healthiest choice.
We just do the best we can, right?
The best we can do down the list:
1. Grow it ourselves
2. Forage
3. Get to know our local farmer/U-pick/farmer's market
4. Buy as much organic as we can and/or ask for it at our local grocer
5. Buy the "safer" conventional produce which has the least amount of pestcides when necessary and buy the "higher pesticide" produce organic.
http://www.sdearthtimes.com/et0996/et0996s5.html
6. Happily buy conventional produce when the need arises because it's still a healthier choice than an 'organic' cooked meal, right?