ABSTRACT
There are both radioactive and non-radioactive isotopes of iodine. The isotopes of iodine include iodine-123, iodine-124, iodine-125, iodine-129, and iodine-131. Iodine-129 and iodine-131 are the most important radioactive isotopes in the environment. Some isotopes of iodine, such as I-123 and I-124, are used in medical imaging and treatment but are generally not a problem in the environment because they have very short half-lives. Iodine is a trace element necessary to life in very small quantities but deadly at higher concentrations and thus required by all humans in small amounts for healthy growth and development. Radioactive iodine is used in medical tests and to treat certain diseases, such as overactivity or cancer of the thyroid gland.
