How dangerous is low-level radiation? Perhaps, much less riskier than we think.

Everyone knows that high levels of radiation are deadly. It seems that no one is certain of how much low-level radiation poses a serious health threat. It’s one of the things that makes the nuclear disaster in Japan such a cause for fear and anguish. One of the problems of assessing the risk is that it’s very hard to study low levels of radiation exposure because there are many things that contribute to people getting cancer.

In the September 13th, 201o issue of The New Yorker, noted journalist Peter Hessler, wrote a piece entitled The Uranium Widows: Why Would A Community Want To Return To Milling A Radioactive Element?. It’s about a small community in Colorado that seems overwhelmingly positive about plans to build America’s first new uranium mill in thirty years. Hessler was first skeptical about the public reception as well but after spent months researching the dangers of radiation, he reached some conclusions that surprised himself. With his permission, we’re reprinting the relevant portions of the article.  Hessler is not a nuclear scientist but he is a highly credible journalist and a meticulous researcher; he is also not a flack for the nuclear power industry. He backs up his article with a number of reliable sources.   This may not answer the question on the minds of all those in Japan and in Tokyo, but perhaps it will give some perspective.*

—The effects of high doses are well documented, largely because of a sixty-year study of nearly a hundred thousand Japanese atomic-bomb survivors. With high levels of radiation, there’s a clear linear pattern—more exposure means an incremental rise in risk. But it’s unclear whether this pattern continues into the lower-dose range, where any health effects are so small that they can’t be demonstrated by epidemiological studies. Some experts and scientific bodies, including the French Academy of Sciences, have questioned the linear model for low levels, believing that radiation may be harmless up to a certain threshold. This is a controversial idea, because it would radically change risk assessment, as well as possible solutions for the storage of nuclear waste.

United States regulations continue to follow the linear no-threshold theory. It has the benefit of being simple and safe, but it can also be misinterpreted. Because of Colorado’s elevation, a resident there receives two to three times the natural background radiation of someone who lives in New Jersey, so strictly speaking there should be an increased risk of cancer.  (In fact, Colorado cancer rates are lower.) After the Chernobyl accident, in 1986, anti-nuclear groups and scientists used the findings from the Japanese atomic-bomb survivors, extrapolated downward for the radiation levels in Europe, and predicted tens of thousands of deaths from cancer. Critics note that this is like taking a set of deaths from motorists who drove a curve at a hundred miles an hour and making the assumption that, if people slow to ten miles an hour, they’ll die at a tenth of the original rate. This is also why a hundred and twenty-seven million dollars was spent obsessively cleaning up an abandoned town whose former residents lived longer than the national average.

Even worst-case disasters reveal surprisingly small effects. In Chernobyl, dozens of emergency workers died after fighting the reactor fire, but the health impact on neighboring communities seems to be limited. After more than twenty years of extensive study, there is no consistent evidence of increased birth defects, leukemia, or most other radiation related diseases. The only public epidemic consists of high rates of thyroid cancer in children, whose glands are particularly sensitive to radiation. Fewer than ten people have died—thyroid cancer is usually treatable—although it will be years before the full impact of the epidemic is known.  But, like the accident itself, it could have been avoided entirely. The Soviet reactor lacked a containment facility, and the Communist government delayed announcing the accident.

Dr. John Boice, who founded the radiation epidemiology branch of the National Cancer Institute, spoke with Peter Hessler. Dr. Boice now teaches at Vanderbilt School of Medicine, and is also the scientific director of the International Epidemiological Institute, an independent research organization.

“The Russians could have done one thing that would have gotten rid of the epidemic of thyroid cancer,” Boice told me. “They could have said, ‘Don’t drink the milk.’ ” In surrounding areas, cows ate grass contaminated by fallout, and people fed the milk to their children. An open society probably would have responded differently; even as far back as 1957, when a fire at a badly designed British nuclear facility called Windscale released radiation, all local milk was dumped into the sea.

Boice told me that the biggest health problems from high-profile accidents are often psychological. A twenty-year study showed no consistent evidence that the low amounts of radioactivity released in the Three Mile Island accident have had a significant impact on mortality in communities around the reactor.

The World Health Organization does not classify uranium as a human carcinogen.  The walls of Grand Central Terminal are made of granite, which contains elements that produce radon; a worker there receives a larger dose of radiation than the Nuclear Regulatory Commission allows a uranium mill to emit to a next-door neighbor.  Being closer to the sun—living in the mountains, flying in planes—also means more radiation. According to the National Council on Radiation Protection and Measurements, the average airline crewmember receives an annual dose of work-related radiation that is more than one and a half times higher than that of the average employee in the nuclear power industry. (Neither dose is higher than what the typical American receives from natural background radiation.) And there is no compelling evidence that low amounts of radiation cause health problems.—

★The situation at Fukushima reactor is still uncertain but hopeful. If you are close to the reactor or highly irradiated areas, you  may also find the Centers For Disease Control and Prevention (CDC) FAQ on Radiation Contamination and Radiation Exposure useful as well. I don’t think that people living in Tokyo face any serious risk but for your own peace of mind, this is probably worth reading as well.

Disclosure: Peter and I grew up in the same town and were friends in high school, so there is a personal connection. I thought the article was extremely helpful and am thankful he shared it with me. Comments are welcome.