For more than one hundred years, ionizing radiation and its biological effects have been a subject of scientific investigation. In these investigations, Dose-Effect-Relation is a most important correlation in proving causality between absorbed radiation dose and observed effect; that is, where effect is observed to increase with dose of a physical or chemical agent, then the agent can be considered as a cause. In Dose-Effect Rate research, not only is investigation of deterministic radiation effects from high radiation exposure important, the stochastic effects from low dose exposure are also important. The former high radiation exposure, through cancer induction, can affect an exposed person, the latter, low dose exposure, through genetic mutation, can affect the person's descendants.
For a number of carefully carried out epidemiological studies of exposed persons which are accepted in the scientific literature, the dose fractions or doses respectively and the derived number of tracks per cell nucleus per exposure are compiled in the table.
In all nine studies a significant increase in cancer incidence has been observed in the exposed population.