
Analysts at EWG synthesized data collected from the U.S. Department of Agriculture and the Food and Drug Administration from 2000 to 2009. Produce is ranked based on a composite score, equally weighing six factors that reflect how many pesticides was found in testing of on each type of the produce and at what levels. Most samples are washed and peeled prior to being tested, so the rankings reflect the amounts of the chemicals likely present on the food when is it eaten.