“Radiation” is energy that travels through space. The sun, x-ray machines, microwave ovens, nuclear reactors and power lines, just to name a few sources, all produce radiation.

Radiation comes in two main flavors: ionizing and non-ionizing. What ionizing means is that there is enough energy contained in the radiation to “ionize” atoms, meaning that electrons are detached from their atoms. Examples of ionizing radiation include (a) from the electromagnetic spectrum: ultraviolet (UV) radiation, X-rays, and gamma rays and (b) subatomic particles such as alpha particles, beta particles, and neutrons. Note that subatomic particles are emitted as atoms from “radioactive substances” decay. These high-energy forms of radiation can damage living tissue.

Non-ionizing radiation is lower energy radiation that does not have enough power to detach electrons. Common examples of non-ionizing radiation include
radiowaves, microwaves, visible light and infrared light. While both types of radiation can be harmful to humans, ionizing radiation is more dangerous.

On average, each of receive about 620 millirem of ionizing radiation each year from the following sources:

Here is additional information about the amount of ionizing radiation we receive:

Note that you “receive” 40 millirems of radiation annually from your own body! This is equivalent to four chest x-rays. Additionally, sleeping next to another person adds a few millirems of radiation a year that you receive from their body!

Where does our own radioactivity come from? According to Symmetry Magazine: ” You emit radiation because many of the foods you eat, the beverages you drink and even the air you breathe contain radionuclides such as Potassium-40 and Carbon-14. They are incorporated into your molecules and eventually decay and produce radiation in your body.”