Radioactive isotopes, also known as radioisotopes, are any examples of one chemical element which do not have as many neutrons as the usual atom and whose nucleus is unstable, and which dissipate energy in the form of alpha, beta, and gamma rays. The final product is an isotope of another element which is not radioactive, as when radium-226 decays and becomes lead-206. Every element has at least one isotope. By way of example, the lightest element, hydrogen, has three isotopes with masses one one, two, and three. Only tritium – hydrogen-3 – is radioactive, while the other two are stable. Around 3,800 radioactive isotopes of different elements are known to exist. Around 50 occur naturally, originating before the creation of the earth or from cosmic ray interactions. Radioactivity is common in rocks, soil, and water. The other isotopes are produced artificially by nuclear reactions or as the descendants of these products.
How Do Radioactive Isotopes Occur?
The average person takes in more than 2,000µSv of radiation a year, of which 82 percent is from natural sources, 18 percent from medical treatment, and less than one percent from nuclear power and fallout. The amount arising from use of radioactive isotopes in medical treatment has risen in recent years due to increased use of computed tomography and nuclear medicine. The Nuclear Threat Initiative, an American think tank, recently declared that the radiation in bananas could be sufficient to trigger the radiation sensors used at U.S. ports.
Radioactive isotopes are very useful. When small amounts of a radioactive isotope are added to a large quantity of the stable form of the element, it acts exactly like the regular isotope chemically, but can be tracked using a detection device such as a Geiger counter.
Medical Uses of Radioactive Isotopes
In medicine, cobalt-60 is widely used to halt the development of cancer by killing abnormal cells in such cases as polycythemia (an increase in red cells) and leukemia (an increase in white cells). Chromium-51 is used to measure protein loss and classify blood cells. Technetium-99 and oxygen-18 can be used as tracers for diagnosis, allowing organic and inorganic substances in the body to be followed, which is often not possible to achieve by other means. Iodine-131 has been found to be effective in determining thyroid and liver activity and cardiac output, and locating brain tumors. Carbon-14 is used to study the metabolic abnormalities which are associated with acromegaly, anemia, gout, and diabetes. Radioactive isotopes are also employed in the research of metabolic processes.
Industrial Uses of Radioactive Isotopes
Radioactive isotopes are made use of in industry to measure the thickness of or identify wear in plastic or metal by the strength of radiation which penetrates. Magnesium-27 and sodium-24 can locate fractures in water pipes. It is also possible to use radioactive isoptopes instead of bulky X-ray equipment to identify structural defects in manufactured metal parts. Another significant application is their use as sources of electricity, for instance plutonium-238 in spacecraft and cardiac pacemakers: the heat they produce while decaying is converted to electricity by thermoelectric junction circuits or similar devices.
Other Uses of Radioactive Isotopes
In archeology, the radioactive isotopes carbon-14, potassium-40, and lead-210 are used to date rocks. Tritium and chlorine-36 are used to determine the age of water found underground to as much as millions of years.
Within the last 100 years, nuclear chemistry has begun to touch the lives of everyone. While radioactive isotopes provide many benefits, people are usually not aware of them.