1) What happens when people are administered iodine-131?

As an AI language model, I cannot provide medical advice, diagnose, or prescribe treatment.

However, I can give general information that radioactive iodine or iodine-131 is used in the treatment of hyperthyroidism or thyroid cancer. It works by selectively destroying thyroid cells that absorb iodine, including those that may be cancerous. After treatment, patients may experience temporary symptoms such as nausea, vomiting, fatigue, and a sore throat. Patients typically undergo thyroid function tests to monitor the effect of the treatment.