The Pesticide Action Network North America (PANNA) has reported that a number of pesticides can be associated with things like nerve damage, ADD and autism, cancer, and birth defects.
The following two examples should be avoided:
Atrazine (found in corn sugarcane, and other grains)- This can cause heart damage, muscle spasms, eye and skin irritation, and is considered an endocrine disrupter. It has been banned in most of Europe, but is widely used in the U.S.
Dursban (used on apples, almonds, alfalfa, oranges, corn, and walnuts)- This is a bad substance. The EPA has banned it in most NON-agricultural uses (like flea collars and termite sprays) but continues to allow it on food sources.
Reminder: Always read labels. Know what you are putting in your body. You need to look out for your health because the government agencies sure don't.