Within ten years of the accident, it became clear that thyroid damage caused by released radioactive iodine was virtually the only adverse health effect that could be measured. As reported by the NRC, studies after the accident showed that "As of 1996, except for thyroid cancer, there has been no confirmed increase in the rates of other cancers, including leukemia, among the... public, that have been attributed to releases from the accident. "But equally important to the question of KI is the fact that radioactivity releases are not "local" events. Researchers at the World Health Organization accurately located and counted the residents with cancer from Chernobyl and were startled to find that "the increase in incidence [of thyroid cancer] has been documented up to 500 km from the accident site... significant doses from radioactive iodine can occur hundreds of kilometers from the site, beyond emergency planning zones." Consequently, far more people than anticipated were affected by the radiation, which caused the United Nations to report in 2002 that "The number of people with thyroid cancer... has exceeded expectations. Over 11,000 cases have already been reported." Nagasaki
These findings were consistent with studies of the effects of previous radioactivity releases. In 1945, millions of Japanese were exposed to radiation from nuclear weapons, and the effects can still be measured.
For SSKI, a solution more viscous than water, there are assumed to be 15 drops per mL; the iodide dose is therefore approximately 51 mg per drop. It is conventionally rounded to 50 mg per drop. The term SSKI is also used, especially by pharmacists, to refer to a U.S.P. pre-prepared solution formula, made by adding KI to water to prepare a solution containing 1000 mg KI per mL solution (100% wt/volume KI solution), to closely approximate the concentration of SSKI made by saturation. This is essentially interchangeable with SSKI made by saturation, and also contains about 50 mg iodide per drop. Saturated solutions of potassium iodide can be an emergency treatment for hyperthyroidism (so-called thyroid storm), as high amounts of iodide temporarily suppress secretion of thyroxine from the thyroid gland. The dose typically begins with a loading dose, then 1⁄3 mL SSKI (5 drops or 250 mg iodine as iodide), three times per day. Iodide solutions made from a few drops of SSKI added to drinks have also been used as expectorants to increase the water content of respiratory secretions and encourage effective coughing. SSKI has been proposed as a topical treatment for sporotrichosis, but no trials have been conducted to determine the efficacy or side effects of such treatment. Potassium iodide has been used for symptomatic treatment of erythema nodosum patients for persistent lesions whose cause remains unknown. It has been used in cases of erythema nodosum associated with Crohns disease.