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.

When measuring dose the instrument measures the energy absorbed in a given material, which is denoted absorbed dose (a quantity which has the unit Gy = J/kg). Through calibration, which is done through multiplication by a factor defined by the material’s radiation response, i.e. the effect of radiation on the biological tissue of relevance, the measured absorbed dose is translated to effective dose, which is expressed in a unit called Sievert, abbreviated Sv.

In addition to the amount of radiation (absorbed dose) and the ability of the biological tissue to absorb the radiation, effective dose also depends on the type of radiation to which the biological tissue is exposed. It can be electromagnetic radiation (gamma and X-ray radiation), electron radiation, alpha radiation, or neutron radiation.

The biological effect of the radiation differs depending on the type of radiation, but when radiation exposure is expressed in terms of an effective dose, this has been taken into account through the weighting factor used to convert absorbed dose to effective dose.

Health effects

The sensitivity to radiation differs between organs. Typically, organs with more frequent cell division are more sensitive to sensitive to radiation than other organs..