IONIZING RADIATION

Radiation is a form of energy. There are two basic types of radiation, ionizing and non-ionizing radiation. The BASIC difference between them is the amount of energy they possess. Ionizing radiation has higher energy and has an ability to break chemical bonds, causing ionization of atoms and produce free radicals that can result in biological damage. Non-ionizing radiation does not have enough energy to cause ionization but disperses the energy through heat.

Non-ionizing radiation such as radio-waves, microwaves, radar, microwaves and visible light is not able to break chemical bonds the biological responses to this exposure are not related to events such as mutations or chromosome aberrations but are related to physiological changes.

Ionizing radiation consists of both particles and photons. The examples of particles include electrons, protons, neutrons and alpha particles. The most common photons with enough energy to produce ions, break chemical bonds and alter biological function are short wavelength (below about 300 nm), x-rays and gamma rays. Exposure to such radiation can cause cellular and molecular changes such as mutations, chromosome aberrations and cell killing. At high doses, it is well-established that ionizing radiation is capable of inducing cancer. Radioactive elements such as uranium, plutonium, cesium and cobalt emit high energy ionizing radiations (X-ray). X-ray/gamma ray and neutrons can pass right through the human body. Ionizing radiations are also referred to simply as radiation on this web site. We can't see, smell or feel ionizing radiation, but it is nonetheless very dangerous.
 

High LET (Linear Energy Transfer) Radiation: As the radiation interacts with matter, it loses its energy through interactions with the atoms. The average amount of energy that is lost over a defined distance, for example the energy deposited in ten cells, is known as the Linear Energy Transfer (LET). Some types of radiation, such as alpha particles, deposit a large amount of energy in a small distance (e.g., 20 microns, a few cells) and are called high-LET radiation. Other radiation types such as x-rays or gamma rays penetrate tissues very easily and very little deposition of energy. High-LET radiation is more effective in producing cancer and other cellular and molecular damage per unit of exposure or dose than low-LET exposure.