Congenital iodine deficiency syndrome Congenital iodine deficiency syndrome Congenital iodine deficiency syndrome, previously known as cretinism, is a condition of severely stunted physical and mental growth owing to untreated congenital deficiency of thyroid hormone (congenital hypothyroidism) usually owing to maternal hypothyroidism. Around the world, the most common cause of congenital hypothyroidism is iodine deficiency. It has affected many people worldwide and continues to be a major public health problem in many countries. Iodine is an essential trace element, necessary primarily for the synthesis of thyroid hormones. Iodine deficiency is the most common preventable cause of brain damage worldwide. Although iodine is found in many
Isotopes of iodine other form of direct radiation). The protective effect of KI lasts approximately 24 hours, so must be dosed daily until a risk of significant exposure to radioiodines from fission products no longer exists. Iodine-131 (the most common radioiodine contaminant in fallout) also decays relatively rapidly with a half-life of eight days, so that 99.95% of the original radioiodine has vanished after three months. Isotopes of iodine There are 37 known isotopes of iodine (I) from I to I; all undergo radioactive decay except I, which is stable. Iodine is thus a monoisotopic element. Its longest-lived radioactive isotope, I, has a