According to Paul Pitchford in his book, "Heaing with Whole Foods," buckwheat contains the glucoside rutin, which protoects against the effects of radiation. Apples and fresh sunflower seeds contain pectin which bind radioactive residues and removes them from the body. Bentonite clay and lecithin also have this action. Lecithin dosage is 1 teaspoon daily. Barley grass is also helpful.
External treatment in any type of radiation exposure is a bath of one pound sea salt and one pound of baking soda. If there is serious radiation exposure, use this bath three times a week for a month.