This helps physicians locate and identify tumors, size anomalies, or other physiological or functional organ problems.
In addition, hospitals and radiology centers perform approximately 10 million nuclear medicine procedures in the United States each year.
Carbon is a very important chemical element, with a chemical symbol of C. Many of the substances that people use daily are organic compounds.
Carbon, hydrogen, nitrogen, oxygen, and some other elements like sulfur and phosphorus together form most life on earth (see Organic chemistry and List of biologically important elements).
Archaeologists also use radioactive substances to determine the ages of fossils and other objects through a process called carbon dating.
For example, in the upper levels of our atmosphere, cosmic rays strike nitrogen atoms and form a naturally radioactive isotope called carbon-14.
When used in this way, they are most often intended to kill cancerous tissue, reduce the size of a tumor, or reduce pain.
For example, radioactive iodine (specifically iodine-131) is frequently used to treat thyroid cancer, a disease that strikes about 11,000 Americans every year.