Survive the A-Bomb, Die Prematurely from Stroke and Heart Disease

The survivors of the World War II atomic bombings of Hiroshima and Nagasaki may have considered themselves lucky, at least at first. Shortly thereafter, however, those who didn’t die from radiation poisoning learned that the radiation from the bombings placed themselves and their children at increased risk of cancer. Now, they can add heart disease and stroke to their list of potential medical problems.

A recent article in the British Medical Journal (BMJ) examined the rates of death from heart disease and stroke in survivors of these bombings based on their distance from the epicenter and subsequent calculated radiation exposure. It found that those exposed to higher doses of radiation had an increased risk of both stroke and heart disease, with excess relative risk per gray of radiation of 9% for the former and 14% for the latter. Correcting for other habits known to be associated with both conditions had no impact on their findings, suggesting that the radiation alone was responsible for their findings.

While no one anticipates another atomic bombing, the results of this study are still relevant due to the widespread exposure of individuals to radiation from medical diagnostic tests such as CT scans. According to a publication from the Health Physics Society, the standard CT scan of the pelvis delivers approximately 10 mSv of radiation (by comparison, people are exposed to 3 mSv from natural background radiation yearly).  An angioplasty can deliver up to 57 mSv. Not only that, it has become increasingly apparent that even modern radiologic equipment is prone to failure, with recent reports of patients receiving several-fold greater doses of radiation than intended.  Once felt to be administered with doses of radiation too low to cause any long-term ill effects, such tests are likely to come under increased scrutiny as potential causative agents in cardiovascular disease.

Reference

Little, M. (2010). Exposure to radiation and higher risk of circulatory disease BMJ, 340 (jan14 1) DOI: 10.1136/bmj.b4326;340:b5349. doi:10.1136/bmj.b5349

Radiation Exposure from Medical Diagnositic Imaging Procedures: Health Physics Society Fact Sheet [PDF].