Choosing organic foods may reduce carbon dioxide emissions by up to 68 percent. That said, going all organic all the time can take a toll on your wallet. If you also buy organic because you’re concerned about your personal health, consider forgoing organic if/when you buy these 15 fruits and vegetables (they make up the Environmental Working Group’s “Clean 15” list as least likely to be contaminated with pesticide residues): onions, corn, pineapple, avocado, asparagus, sweet peas, mango, eggplant, cantaloupe, kiwi, cabbage, watermelon, sweet potatoes, grapefruit and mushrooms.