We previously covered the dangers of toxins present on the fruits and vegetables we eat. The list of the dirty dozen for 2013 are the twelve produce items you should be most concerned about. When buying these make sure to look for the USDA Organic label and to be diligent when cleaning them before cooking or eating.
There is also a list of the clean fifteen. This is a list of the produce foods that are least likely to test positive for pesticide residue. While better odds than the items on the dirty dozen list, even these fifteen fruits and vegetables were found to have some pesticide evidence, ranging from 5 to 20% of the tested foods. They were often found to only have one pesticide on them, compared to the dirty dozen that often had multiple forms of synthetic substances.
The analysis and results are provided by the Environmental Working Group (EWG). Each year they independently develop these lists to draw awareness to eating clean and the use of organic farming methods. They state that their aim is to "give consumers confidence that by following EWG's advice, they can buy foods with fewer types of pesticides and lower overall concentrations of pesticide residues." Additional information can be found on their website.