institute of radiation biology

Scientific challenges facing radiation biology in the next decade

Exposure to ionizing radiation will continue, be they from natural "background" sources such as domestic radon or high altitude jet travel, from medical procedures such as imaging and cancer therapy, or from accidental or malevolent environmental releases. These exposures have the potential to induce long-term detrimental health effects.

Whilst the risks of exposure to high doses are quantifiable, effective management of adverse effects remains problematical. As cancer survivorship increases the need to protect healthy tissue during radiation therapy increases. Concerns about damage to the cardiovascular system illustrate our lack of understanding about such non-cancer late effects of high dose exposure. Potential effects on the neurological and immune systems cannot be excluded.

At low doses little consensus exists on the potential risk, if any, of late-developing health effects. Uncertainty over the risk of low doses are strengthened by reports demonstrating non targeted effects in exposed tissues that predict a non-linear dose response curve, which is in direct conflict to the prevailing dogma of a linear response mediated only by DNA damage. Indeed, the lack of knowledge of how ionizing radiation causes damage, will continue to present a challenge to experimental radiation biologists.

Genetic predisposition to the adverse acute and long-term effects of ionizing radiation has long been recognized, but identification of genetically at risk individuals prior to therapeutic exposures remains in its infancy. Genetic risk prediction at low dose exposures presents a significant challenge as the contribution of several million gene polymorphisms must be considered.