Iodine-131 (t1/2 = 8.04 d) is widely used in nuclear medicine, primarily to treat hyperthyroidism and thyroid cancer, with an annual average of 188 treatments per million people in developed countries. The administered dose of Iodine-131 (∼0.1−1 and 4−8 Gbq for hyperthyroidism and thyroid cancer, respectively) is metabolized by patients and eliminated from the body mostly in urine. In the United States, patient excreta are exempt from sewer discharge regulations and are released directly into sewerage. → Go to Full Report
