What is organic food and what’s the big deal?
By definition, organic food is: produced using methods not involving synthetic pesticides and chemical fertilizers, does not contain genetically modified organisms, and no use of irradiation, industrial solvents, or chemical food additives. Foods that contain high levels of pesticides can lead to higher rates of cancer, skin irritation, infertility, and birth defects and brain damage in children, among other side effects that have yet to be discovered. http://nanopatentsandinnovations.blogspot.com/2011/05/8-possible-side-effects-of-pesticides.html
The Environmental Working Group (EWG) has a list of foods that consumers should buy organic whenever possible. This list is called the Dirty Dozen and contains foods that are notoriously high in levels of pesticide and insecticide contamination.
Worst of the Dirty Dozen™
#1 Apples
Eaten daily by many children, 98 percent of conventional apples had pesticides.
#2 Celery
Highly contaminated, celery tested positive for 57 different pesticides.
#3 Bell Peppers
Bell peppers tested positive for up to 15 pesticides on a single sample.
The foods with the lowest amount of pesticides are on the Clean Fifteen list:
Best of the Clean 15™
#1 Onions
Conventional onions are a clean crop. Less than 1 percent of samples had any pesticides.
#2 Sweet Corn
98 percent of all frozen and sweet corn samples had no detectable pesticide residues.
#3 Pineapples
Only 6 different pesticides were found on pineapples.
For the full lists: http://www.ewg.org/foodnews/summary/