| There are different types of radiation; some are more
energetic than others. For example, non-ionizing radiation, has enough
energy to move atoms around, but not enough to change them chemically.
The most energetic form of radiation is called ionizing radiation. We
are concerned with protecting people and the environment from
potentially harmful exposures to ionizing radiation.
We measure radiation dose in units called rem.
Scientists estimate that the average person in the United States
receives a dose of about 360 millirem of radiation per year. But what
are the sources of that exposure: where does it come from?
Eighty percent of human exposure comes from natural
sources: radon gas, the human body, outer space, and rocks and soil. The
remaining twenty percent comes from man-made radiation sources,
primarily medical X-rays. |
 |
