Milligram Equivalent of Radium

The milligram equivalent of radium is an obsolete unit of measurement of radioactivity. It was introduced to evaluate the biological effects of radiation from radium and radioactive elements of its series.

A milligram equivalent of radium is numerically equal to the radioactivity of 1 mg of pure radium. It was used to express the activity of radioactive substances in units of mass of radium, which has equivalent biological activity.

Currently, this unit is not used, as it was replaced by a more universal unit - the gamma equivalent. Gamma equivalent expresses the activity of a radionuclide in units of the activity of radium-226, which has the equivalent biological effectiveness of gamma radiation.

Thus, the milligram equivalent of radium is considered an obsolete unit of radioactivity that was replaced by the gamma equivalent to more accurately assess the biological effects of ionizing radiation.