Sometimes washing your fruit and vegetables isn't enough to remove all the pesticide residue from your diet. There are extra steps you can take to make sure you're avoiding potentially-hazardous chemicals next time you want some produce.
For one, certified-organic food does not necessarily mean certified-pesticide-free or -chemical-free. Even naturally-derived pesticides can be known to cause harm, especially because it often requires more applications than non-organic pesticides.
Secondly, peel your produce! Studies show that peeling and cooking produce caused a significant reduction in the residue of common pesticides much moreso than washing-- in fact, some pesticide residues were not decreased at all by washing. Peeling takes the top spot in importance though, as cooking unpeeled produce has been shown to facilitate transfer of chemicals from peel to the produce's flesh.
Finally, be aware that not all produce is farmed equally-- in conventionally-farmed (that is, non-organic) produce, certain fruits and vegetables were found to be "dirtier" than others in terms of residual pesticide content. Apples, grapes, celery, and kale that is conventionally produced have been found to have high residual chemical levels; onions, sweet corn, and pineapples have been found to be relatively clean by comparison. Check out a full list of dirty and clean conventional produce at http://www.ewg.org/foodnews/summary.php.