The answer about foods with thick outer skins being less likely to contain pesticide residue is correct. However, some extremely dangerous pesticides are being used quite liberally on other produce (veggies and fruits) with thin skins. You couldn't pay me to eat a non-organic commercially-grown tomato, squash or strawberry!
California recently approved the use of a dangerously toxic pesticide for strawberries, chili peppers and other produce crops. Farm workers and environmental organizations filed a lawsuit against the so-called Pesticide Regulation Department, and the scientists on the department's own advisory panel warned that it's an "extremely toxic and dangerous chemical"--to no avail. Heavy spraying with this poison went right ahead. When the bottom line is at stake, you can't count on any official agency to protect you and your family. You must do it yourself! That doesn't, of course, help the farmworkers exposed to this poison or the people living in close proximity who get run-off water with this toxin. So, no, Earl....all food is NOT safe to eat to a certain degree.