What Is Radiation?

Answer:

Radiation is energy. It travels through space in the form of particles or waves. Radiation is energy such as heat, light, sound, microwaves, radio waves, X-rays and radar. Radiation is everywhere. It is in the air we breathe, the water we drink, and the food we eat. This makes up the "background radiation" that we are all exposed to everyday.

Radiation can be classified as either ionizing or non-ionizing. Non-ionizing radiation is lower energy radiation that comes from the lower part of the electromagnetic spectrum. It is called non-ionizing because it does not have enough energy to completely remove an electron from an atom or molecule. Ionizing radiation has enough energy to detach electrons from atoms or molecules — the process of ionization. It comes from both subatomic particles and the shorter wavelength portion of the electromagnetic spectrum.

It has been known for many years that large doses of ionising radiation, very much larger than background levels, can cause a measurable increase in cancers after some years delay. Very large doses in the short term cause sickness and even death. The body has defence mechanisms against damage induced by radiation as well as by chemical and other carcinogens. These can be stimulated by low levels of exposure, or overwhelmed by very high levels.

On the other hand, large doses of radiation directed specifically at a tumor are used in radiation therapy to kill cancerous cells, and thereby often save lives (usually in conjunction with chemotherapy or surgery). Much larger doses are used to kill harmful bacteria in food, and to sterilise bandages and other medical equipment. Radiation has become a valuable tool in our modern world.