If you read Consumer Reports magazine, you may go organic. At least when it comes to string beans. The magazine compared 28 fresh vegetables and found that conventionally grown string beans had the highest pesticide risk, by far. The article stated that a serving of green string beans grown in the U.S. was 200 times riskier to eat than a serving of U.S. grown broccoli. To reduce your exposure to pesticides, the magazine recommends buying only organic string beans.