Fukushima After the Meltdown

By Miles O'Brien

When I was growing up in the '60s, I was filled with fear, loathing and fascination over the unmatchable power that is unleashed by splitting the atom.

I was four when President Kennedy signed the Limited Nuclear Test Ban Treaty in 1963, which banned atmospheric testing of atomic weapons. The tests were the largest single source of cesium-137 fallout in the history of the atomic age. Cesium-137 has a half-life of 30 years, so most of it has decayed, but those of us who were breathing air at that time likely carry some of the contamination with us to this day.

It is that long tail of consequence that makes the debate over nuclear power so volatile. While accidents are extremely rare, they have far-reaching implications.

The reality of this first hit me a year ago when I went to Chernobyl to do a story on what scientists know about the impact of the meltdown there 25 years ago on the people and the environment in Ukraine and Belarus.

The area around Chernobyl is still fenced off and largely uninhabited -- an exclusion zone that was created shortly after the reactor exploded and began burning. Closest to the plant is the old Soviet style company town of Pripyat, which became an instant ghost town -- and a rotting relic of all that ailed that flawed system.

Unfortunately, the commissars of that dying empire had little interest in a free and open exchange of peer-reviewed scientific data (to say the least), and thus no reliable research was done from the outset. It was a terrible missed opportunity to learn something about what a long-term, low-dose of radiation exposure might mean for human health.

This is a tough scientific nut to crack. Human beings get cancer for all kinds of reasons - both genetic and environmental. And those cancers often take many decades to become evident. So how to connect the dots between a given cancer and exposure to fallout?

We will never get closer to any answers because of scientific studies on the people affected by Chernobyl. They just do not exist.

The best study that exists to date focuses on 94,000 survivors of the 1945 atomic bomb attacks on Hiroshima and Nagasaki. The laws of physics combined with the vivid memories of people who were there on those awful days allowed scientists to very precisely determine how big a dose of radiation an individual received. In addition, our teeth store telltale evidence of the amount of radiation to which we've been exposed.

The Radiation Effect Research Foundation (formerly the Atomic Bomb Casualty Commission) - a joint U.S. and Japan project - still studies these survivors in great detail. There are very few long-term scientific studies that would compare to the scope and depth of this project (the Framingham Heart Study comes to mind).

After all these years of research, they can say with certainty that radiation exposure causes cancer in humans: leukemia fairly soon, and solid cancers many decades later. But below 100 millisieverts, they can find no smoking-gun link between any health effects and radiation exposure.

Scientists will tell you there is no such thing as a "safe" amount of radiation. It is a sure-fired mutagen that bombards DNA with energy - causing mutations to our genes. But it is relatively weak, and so we often find ourselves groping for answers below the "noise". The cancer rate in Japan for the general population is about 40%.

To complicate the picture further, scientists believe that an instantaneous exposure of a given amount of radiation is more hazardous to us than the same dose over a long period of time. The body is pretty good at healing itself.

But no one has studied a population that has been exposed this way. Sadly, there is now another group of people in Japan who offer science an opportunity to fill in some of these blanks. But quantifying the amount of exposure a person from the Fukushima region may be exposed to over a long period of time will not be easy.

So will we ever get an answer? John Boice, a professor of medicine at Vanderbilt University -- and an expert on this issue -- is hoping The One Million U.S. Radiation Worker Study helps us understand what happens to people who get a low, steady dose of radiation over a long period of time.

The study is focusing on uranium workers at multiple Department of Energy locations, atomic veterans, nuclear power plant workers, industrial radiographers, radiologists and other medical practitioners, and Department of Energy plutonium workers.

A team of 30 scientists is studying their medical records - and in many cases causes of death - and comparing that to their lifetime exposure to radiation. The big advantage here: workers in this environment wear devices (so-called film badges) that measure their cumulative dose. Maybe the needle lies somewhere in this haystack. But it will take a decade to know for sure.

Meantime, the international organizations that set the standards for allowable exposure to radiation among radiation workers and the general populace are erring on the side of conservatism. The rules say an average person should only be exposed to 1 millisievert above background radiation (about 3 millisieverts, depending on where you live) and 20 millisieverts above background for radiation workers.

After the Fukushima meltdowns, the Japanese government has said the standard for radiation workers should apply to all people. But even with that change, huge swaths of land around the nuclear plant remain vacant - and will for many years to come. But the truth is, no one knows if radiation at that level poses any a health risk at all. Not yet.

But, of course, no one wants to make this population radiation guinea pigs.

The biggest health risk to the people of the Fukushima prefecture may be linked to the psychological impact of having to leave their ancestral homes for good - or living with the sense of unease that comes from not knowing if you are being slowly poisoned by something you cannot see, smell or taste.

This cries out for more study. And when the answers come in, people need to listen to the facts and not allow irrational fear of radiation to rule the day.