What levels of radiation are people exposed to in everyday life?

It helps to be aware of the radiation levels people encounter in everyday life. Individual exposures vary, but humans are exposed routinely to radiation from both natural sources, such as cosmic rays from the sun and indoor radon, and from manufactured sources, such as televisions and medical x-rays. Even the human body contains natural radioactive elements.

Because individual human exposures to radiation are usually small, the millirem (one one-thousandth of a rem) is generally used to express the doses humans receive. The following table shows average radiation doses from several common sources of human exposure.