What is meant by a non-threshold dose-response relationship?

In the context of radiobiology and dose-response relationships, a non-threshold dose-response relationship indicates that all levels of exposure to radiation have the potential to produce harmful effects. This means that even very low doses, which may not be immediately apparent or observable, can still lead to biological damage over time.

Unlike a threshold relationship, where effects only occur once a certain dose level is reached, the non-threshold model suggests that there is no safe dose of radiation; any amount can contribute to risk. This is particularly significant when considering long-term health impacts, such as cancer risk, where even small accumulations of radiation exposure can increase the likelihood of negative outcomes.

This understanding is foundational in radiation safety and protection protocols, emphasizing the need for minimizing exposure to radiation whenever possible, regardless of the dose level.