Findings from a new study suggest that low exposure to ionising radiation at doses of around 0.5Gy, the equivalent of repeated CT scans, is associated with a significantly increased risk of cardiovascular damage, even up to decades after exposure.
Scientists at the German Research Center for Environmental Health studied the response of human coronary artery endothelial cells to a relatively low radiation dose of 0.5Gy and found that several permanent alterations occurred in the cells that had the potential to adversely affect their essential function, including inhibition of endothelial nitric oxide synthase (eNOS) activation. Cells damaged by low-dose radiation also produced increased amounts of reactive oxygen species (ROS).
Exposed cardiac endothelial cells were also found to have reduced capacity to degrade oxidised proteins and to be aging prematurely. These harmful changes did not occur immediately but first began in the longer term.
Writing in the International Journal of Radiation Biology, the authors said the changes observed are indicative of long-term premature dysfunction and suggest a mechanistic explanation to epidemiological data showing increased risk of cardiovascular disease after low-dose radiation exposure.