Your strawberries may contain traces of harmful pesticides. The U.S. Department of Agriculture performed tests on over 35,000 fruits and vegetables to determine their levels of pesticides. “Strawberries replaced apples atop the list of fruits and vegetables with the highest level of pesticide residue…Apples still rank in second place—after five years in the top spot—followed by nectarines, peaches, celery, grapes, cherries, spinach, tomatoes, red peppers, cherry tomatoes, cucumbers, hot peppers and kale/collard greens.” If you are worried about your produce containing pesticides, it is best to buy organic.