Radiosensitivity of Cells

Atomic radiations are a very diverse group of physical agents all of which, however, produce damage in living cells. The common property which links them is the ability to knock out electrons from the atoms and molecules through which they pass. This process, known as ionization, is the starting point of radiation injury. Mammalian cells are amongst the most sensitive of all living matter, and this is the reason why such stringent safety precautions are necessary in dealing with radioactive materials or with machines that produce atomic radia tions like X-rays. Yet, paradoxically, it is the high radioresistance of some micro-organisms that has so far prevented sterilization by irradiation from being a useful method for general food preservation. If we knew the mechanism by which radiation kills cells it might be possible to devise means to alter the radiosensitivity of cells and thereby make possible new applications of atomic energy to serve man.