This so-called oxygen effect[1] is most notable when cells are exposed to an ionizing radiation dose.
This may give varying numerical values depending on the chosen biological effect.
Additionally, OER may be presented in terms of hyperoxic environments and/or with altered oxygen baseline, complicating the significance of this value.
The maximum OER ranges from about 2–4 for low-LET radiations such as X-rays, beta particles and gamma rays, whereas the OER is unity for high-LET radiations such as low energy alpha particles.
Hall and Amato J. Giaccia: Radiobiology for the radiologist, Lippincott Williams & Wilkins, 6th Ed., 2006 This oncology article is a stub.