'S' factors for Indian reference man

Estimation of radiation dose actually delivered and absorbed by the human body following administration of certain established radiopharmaceuticals is a very important task. In the case of external dosimetry due to an external radiation source, wherein the dose delivered to the person's body is estimated, specifications of mass, dimensions and elemental composition of organs and tissues are needed. For internal dosimetry, wherein the distribution of the dose inside the body due to an internally administered radioactive compound is estimated, additional physiological data are necessary (e.g. air and water balance, intake and excretion patterns, retention of particulate matter in lungs, etc). Further, for assessment of radiation exposure to the populations, the age dependence on the above factors has also to be taken into account