I just read the letter from the gentleman who is worried about contamination from reusable grocery bags. I would think there is a greater problem of contamination from the shoes of the children whose parents put them in the cart where groceries are placed. Did you ever think where those shoes had walked?
Anybody with an ounce of common sense would wash or wipe off their groceries before putting them away. I always thought it would be a great idea to have a mini cart-wash to return the carts to for a quick clean up before the next person uses it.
Give me a cloth bag any day over dirt from shoes.