Health effects of radiation

Units of measurement:

Gray (Gy)

Unit of an absorbed dose, indicating how much energy the ionizing radiation gives out to the target substance. 1 Gy = 1 J/kg.
Sievert (Sv)

A unit of radiation dose indicating the health detriments caused by radiation.

Ionizing radiation can damage the DNA of living cells. In terms of cell damage, what is significant is whether the radiation dose is received over a short or long period. Even a small radiation dose may slightly increase the risk of cancer. A high radiation dose received over a short period of time can cause radiation sickness, tissue damage or foetal damage.

Radiation absorbed into living tissue launches physical and chemical reactions that may cause biological changes. Electrons detached by radiation create reaction products that may cause genetic damage, i.e. damage to the DNA. In addition to DNA damage, other effects, known as epigenetic effects, can also transfer to cells and tissue outside the area exposed to radiation.