You are probably very aware that certain bugs and plants (weeds) can destroy crops and your plants, which is why you might spray certain things from time to time. Consider a massive crop of food that you eat and the amount of bugs that may live and eat in these crops. Do you blame farmers for using pesticides to destroy these bugs? Certainly not, but when you eat the foods that were once sprayed with pesticides, these compounds end up in your body. Again, it does not matter if you washed the fruit or vegetables prior to cooking as these compounds remain regardless. Organic foods do not use any sprays or pesticides, so eating clean tends revolve around no pesticides.