The U.S. government’s updated dietary guidelines encourage Americans to eat more fruits and vegetables, but according to studies, grocery store produce can contain varying amounts of pesticides. The Environmental Working Group, a watchdog organization, looks at U.S. Department of Agriculture data on pesticide residue and releases an annual list of foods that rank highest in pesticide residue (the so-called Dirty Dozen) and those found lowest in residues (the Clean 15). The group suggests eating organic for the top pesticide-containing foods, and notes that you’ll decrease your total pesticide exposure by 80% by doing so.