Iodine deficiency as a side effect of administration of iodine-containing contrast agents. In some cases, excessive iodine contributes to a risk of autoimmune thyroid diseases (Hashimoto's thyroiditis and Graves' disease). Iodine deficiency resulting in goiter occurs 187 million people globally (2.7% of the population). Certain areas of the world, due to natural deficiency and unavailability of iodine, are severely affected by iodine deficiency, which affects approximately two billion people worldwide. It is particularly common in the Western Pacific, South-East Asia and Africa. Among other nations affected by iodine deficiency, China and Kazakhstan have begun taking action, while Russia has not. Successful campaigns
Isotopes of iodine iodine-135 can temporarily preclude a shut-down reactor from restarting. This is known as xenon-poisoning or "falling into an iodine pit". Iodine fission-produced isotopes not discussed above (iodine-128, iodine-130, iodine-132, and iodine-133) have a half lives of a couple of hours or minutes, rendering them almost useless in other applicable areas. Those mentioned are neutron-rich and so go through beta decay to their xenon counterparts. Iodine-128 (25 min half-life) can decay to either tellurium-128 by electron capture, or to xenon-128 by beta decay. It has a specific radioactivity of 2.177 x 10 TBq/g. Colloquially, radioactive materials can be described as "hot,"