Q. Do pesticides get into the flesh of conventional fruits and vegetables like cantaloupe, apples and cucumbers?

A. Pesticides sprayed on fruits and vegetables accumulate on the outer peel or skin, but the skin does not form an impermeable barrier, and some pesticides are actually designed to be absorbed into the tissue of the fruit or vegetable to protect it from pests that penetrate the skin to suck out the liquid inside

Thicker peels may be more effective at keeping pesticides out of the flesh of some fruits like cantaloupe, said Lili He, an assistant professor in food science at the University of Massachusetts, Amherst, who studied the best methods for washing chemical pesticide residues off apples.

If you’re trying to prioritize which fruits and vegetables to buy organic, check the Environmental Working Group’s list of the so-called “Dirty Dozen” and the “Clean Fifteen,” as well as Consumer Reports’ Always Buy Organic list. Both make recommendations based on tests of pesticide residues on fruits and vegetables, done by the United States Department of Agriculture after the produce has been washed.