The fact that they are found at all is only due to the significant advances in analytical chemistry. The tests are now so sensitive that the detection level that can be easily reached is equivalent to detecting one teaspoon of salt in one million gallons of water. Levels even lower than that can sometimes be detected. The mere presence of a trace amount of a pesticide does not mean that the product is unhealthy. On the contrary, eating a diet full of a variety of fruits, grains, and vegetables has been shown to significantly decrease your risk of a variety of health problems from high blood pressure to cancer.
Variety is the key to good health.