Iron is found at the center of every hemoglobin molecule. If this was removed it would no longer be hemoglobin and would be of no value to the body, rendering the donated red blood cells useless. It isn't the iron in the hemoglobin that is removed by chelation. It is the free iron that is left in the body after the transfused blood has broken down, along with any excess iron absorbed from food by the gut, which is removed by chelators. This is the iron that causes the health problems. Since there is no natural way for your body to excrete excess iron, chelators are then used to remove this excess iron.