Jump to main content.  Understanding Radiation: Overview
Ionizing & Non-Ionizing Radiation Radiation that has enough
energy to move atoms in a molecule around or cause them to
vibrate, but not enough to remove electrons, is referred to as
"non-ionizing radiation." Radiation that falls within the
ionizing radiation" range has enough energy to remove tightly
bound electrons from atoms, thus creating ions.  Health Effects
Health effects are the central focus of EPA's Radiation
Protection Programs.  Radiation Protection Basics Three basic
concepts apply to all types of ionizing radiation. When we
develop regulations or standards that limit how much radiation a
person can receive in a particular situation, we consider how
these concepts might affect a person's exposure.  Radiation
Doses in Perspective A dose is the amount of radiation energy
absorbed by the body. The metric system measures dose in
sieverts. The U.S. measures dose in rems. We receive a
background dose of radiation from both natural and man-made so