microroentgens

Microroentgens are a unit of measure for X-ray or gamma radiation dose. Specifically, one microroentgen is equal to one-millionth of a roentgen. The roentgen itself is a historical unit of exposure, defined as the amount of X-ray or gamma radiation that produces an electrical charge of one electrostatic unit in one cubic centimeter of air at standard temperature and pressure. While the roentgen was once widely used, it has largely been superseded by the gray (Gy) and sievert (Sv) in modern scientific and medical contexts, which are based on absorbed dose and equivalent dose respectively. However, microroentgens may still be encountered in older literature or in specific applications where historical units persist. They represent a very small quantity of radiation. For context, natural background radiation levels are often measured in microroentgens per hour. Understanding microroentgens requires an appreciation of the roentgen as a historical unit and its relationship to modern radiation dosimetry units.