Radiological weighting factors
Calculating the equivalent dose from the absorbed dose (in grays) takes into consideration the toxicity of the radiations involved for an equal amount of deposited energy. There is a clear hierarchy among the different types of radiations, with alpha particles proving to be more dangerous when ingested or inhaled than sources of beta or gamma rays. The danger posed by neutrons, which depends on how energetic they are, are still higher but exposures to neutrons are very rare. Protons are only used in rare therapies.