Medical radiation exposure

Information on radiation exposure, health effects and reference doses.

General

Effective dose is a quantity that measures the biological effects of radiation on people, particularly the increase in risk of cancer.

Effective dose is measured in a unit called Sievert, abbreviated Sv. Measuring apparatus for effective dose measure the energy absorbed in material (a quantity of which has a unit Gy=J/kg), but by calibrating to (multiply by an appropriate factor) the radiation produced to cause damage to cells and tissue is measured in the unit Sv.

Effective dose depends on the amount of radiation, the type of the radiation and the organ on which the radiation falls.

The amount of radiation is actually the amount of energy absorbed per unit mass of organs, and this amount is measured in the unit Gy. 1 Gy = 1 J/kg.

The type of radiation refers to whether it is produced by electromagnetic radiation (gamma and X-ray radiation), electron radiation, alpha radiation, or neutron radiation.

Effects on health

Sensitivity to radiation differs between organs. The organs that have frequent cell division are generally more sensitive than others.

When radiation intensity is expressed in Sievert per time unit, for example µSv/h, the effects of different types of radiation have been added up and converted so that it does not matter whether the radiation was, for example, gamma radiation or neutron radiation.