Description

This story of war, science, and health care policy opens in 1950, five years after the end of World War II. Researchers identified more than 86,000 people who survived the atomic blasts. By using their distance from ground zero, whether they were indoors or outside, and other factors, the scientists estimated each person's radiation dose. Then, they waited and watched. As the years passed survivors grew old and died.

Transcript

What do survivors of the atomic bomb blast that destroyed Hiroshima and Nagasaki, Japan 65 years ago have to a health insurance mandate passed by the Texas legislator last year and your desire to guard against heart disease? Well, this story of war, science and health care policy opens in 1950, five years after the end of World War II. Researchers identified more than 86,000 people who survived the atomic blast. And by using their distance from ground zero whether they were indoors or outside and other factors, the scientists were able to estimate each person’s radiation dose, then they waited and watched. As the years passed, survivors grew old and died. Each death and its cause was catalogued and compared to the deaths of other people who were not eliminated by the radioactive rays of the atomic bombs. May of the excess deaths among the atomic bomb survivors were due to cancer and many of our current estimates of the cancer risk of radiation are based on those experiences. Overtime, a smaller but still real risk emerge from the data, there were more cases of heart disease and stroke among bomb survivors. Not many, out of the 19,000 deaths attributed to stroke, heart disease and other circulatory diseases, about 210 were considered excess deaths linked to radiation exposure. A report on the data was published in the journal BMJ, chief scientist Kazunori Kodama and his colleagues call it the strongest evidence yet that moderate radiation is associated not just with cancer but also heart disease and stroke. Kazunori Kodama: Cardiovascular disease is quite prevalent in most of the developing countries and if radiation is indeed causing cardiovascular disease, this is going to be a very important public health problem. The researchers were careful to take into account smoking, diabetes and other known risk factors. But observational studies like this can leave more room for uncertainty than controlled experiments. And the researches say that they didn’t see any effect of lower levels of radiation exposure. The author of an editorial that also appeared in BMJ, Dr. Mark Little, says that the evidence is indeed the best yet but it still leaves important gaps in our understanding. Dr. Mark Little: I’d say the evidence is now a lot stronger in the Japanese atomic bomb survivors… That the excessive heart disease that they have is radiation associated. I mean, the other thing is I think there needs to be much more work done on looking at biological mechanisms that could explain what’s going on. In other words, scientists still aren’t sure exactly how moderate radiation exposure might damage heart and blood vessels. So, what does this all have to do with health care insurance and heart disease risk in Texas? Well last year, the Texas legislator passed a law requiring insurance companies to cover CT scans to look for calcium deposits in arteries that feed blood to the muscle of the heart. These deposits may indicate that plaques are building up in coronary arteries though the exact risk is still a matter of debate, and here’s the link. CT scans used radiation. So could a surge of scanning lead to not only some more cases of cancer but also more heart disease and stroke from the scans that are meant to protect against heart disease? Well, not likely based on the new analysis of atomic bomb survival data. It might take dozens or even hundreds of CT scans to deliver the level of radiation that researchers link to elevated heart disease and stroke. And Dr. Kodama also points out that their study just compared levels of radiation and numbers of deaths. It couldn’t prove that one actually caused the other. Kazunori Kodama: Well, all we found is in the presence of association between atomic bomb radiation exposure and cardiovascular disease mortality. We have to confirm whether the radiation is indeed causing… Scientist involved in this area have to work very hard on this issue and draw conclusions as soon as possible. I think that is the next step and very important. Yet this story is one more example of how the decisions that we make about radiation and health today are based in part on the terrifying experiences of thousands of people whose cities were leveled by radioactive blasts on two summer days in 1945.