Säteilyannostuksen

Säteilyannostus refers to the amount of ionizing radiation absorbed by a material or a living organism. It is a crucial concept in radiation protection and medical physics. The absorbed dose is a fundamental quantity, typically measured in units of Gray (Gy), where one Gray is equivalent to one joule of energy absorbed per kilogram of mass. However, simply knowing the absorbed dose is often insufficient to assess biological risk, as different types of radiation cause varying degrees of biological damage even when delivering the same absorbed dose.

To account for this, the concept of equivalent dose was introduced. Equivalent dose considers the relative biological effectiveness (RBE) of different types of radiation. For instance, alpha particles are more damaging to biological tissues than gamma rays or X-rays, so they have a higher RBE. Equivalent dose is measured in Sievert (Sv). It is calculated by multiplying the absorbed dose by a radiation weighting factor, which is specific to the type of radiation. This weighting factor ensures that the biological effect of different radiation types is comparable.

Furthermore, for scenarios involving internal exposure from radionuclides, the effective dose is used. This takes into account the equivalent dose to individual organs and tissues, weighted by the sensitivity of each organ to radiation-induced cancer. The effective dose provides a single value that represents the overall risk to the entire body, allowing for consistent comparison of risks from various radiation exposure situations. Understanding these different types of dose is essential for accurate risk assessment and implementing effective radiation safety measures.