Each year, the Environmental Working Group (EWG) publishes a list of fruits and vegetables that have high levels of pesticide residue—these are called the Dirty Dozen. Another list is produced to show the produce with the least amount of pesticides—this is called the Clean 15. The lists are based on lab testing done by the US Department of Agriculture (USDA). The results are published in an easy-to-read format so consumers can make informed decisions about what produce to buy organic versus conventional. This is useful information for shoppers on a budget! If you simply don't have enough cash to buy everything organic, use this guide as a reference point and focus primarily on purchasing organic versions of foods from the Dirty Dozen list.