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 sources.