Which fruits and vegetables are the safest to grow and eat in a small garden next to a busy elevated highway?

Question:The garden is 6'x7' and the highway is elevated about 40' about 10' away, up a solid cement wall. It is the busiest highway in Brooklyn, NY (The B.Q.E.). The garden gets a fair amount of sunlight and I add no chemicals to it myself.

Answers:
I wouldn't grow anything that was leafy like spinach or lettuce because of the car exhaust residue that would coat it day after day, but you could try sweet peas. Not snow peas or beans, but the ones that are hidden in a nice pod. That way the automobile pollutants will coat the pod/leaves but when you go to eat them you can pop them out of their shell nice and clean and fresh. Fruits and vegetables that you can peel would be okay like eggplant. Start the peas soon though cause summer will be over before you know it and use some fertilizer.