According to Professor Bruce Ames, a biochemist at UC-Berkeley, our foods contain 10,000 times more natural pesticides than synthetic ones - plants develop their own defenses against fungi and predators. 

Although the minuscule amounts of synthetic pesticides in our foods pose negligible health risks, some activists actually advise consumers not to eat fruits and vegetables at all if they can’t afford organic varieties — in spite of 100 years of evidence that those who eat the most conventionally grown fruits and vegetables have half the cancer rates for practically every type of cancer and live longer than those who eat less.

90% Of the cases “exposed” in EWG’s 2010 list involved levels of pesticides 1,000 times lower than the chronic reference dose - the level of daily exposure likely to be without an appreciable risk of deleterious effects during a lifetime of chronic exposure. 

Dr. Carl Winter and Josh Katz, UC-Davis:

The potential consumer risks from exposure to the most frequently detected pesticides on the ‘Dirty Dozen’ list of foods are negligible and cast doubts as to how consumers avoiding conventional forms of such produce items are improving their health status.