What are the effects of ionising radiation?
The process of ionisation necessarily changes atoms and molecules, at least temporarily, and thus may damages cells. If cellular damage does occur and is not adequately repaired, it may prevent the cell from surviving or reproducing, or it may result in a viable, but modified, cell. The two outcomes have profoundly different implications for the organism as a whole. Most organs and tissues of the body are unaffected by the loss of even a substantial amount of cells, but if the number lost is large enough, there will be observable harm to the individual, reflecting a loss of organ or tissue function. The likelihood of causing such harm will be zero at low doses but, above some level or threshold dose, the damage will occur almost with certainty. Above the threshold, the severity of the harm increases with increasing dose. This type of outcome, which includes acute radiation syndrome, is called deterministic, because the harm is almost bound to occur in exposed individuals if the dose ex
