The answer is: It depends on which radioactive isotopes make it into the jetstream, if any. During the era of atomic testing, government was more concerned with protecting the nuclear industry than with protecting citizens. I worry that this is still the case, especially when I see so-called experts on television claiming that radiation cannot spread beyond 200 kilometers, or 800 kilometers, or whatever number they are touting today.
Let’s get this straight: There is no magic force field preventing radiation from spreading. Declassified documents show that radiation can and will spread around the globe if it enters the jetstream.
Before going any farther, I should explain my background. I am an adjunct historian at a small college in a very red state in the Rocky Mountain West. My specialties are environmental history, and history of technology and science. I am currently working on a dissertation about the atomic testing era. I have been studying this topic for about six years. Because of what I discovered during my research, I became an anti-nuclear activist. I have received various kinds of threats in my community over my political activism, so at the moment I prefer to remain anonymous when writing online. I do not have tenure and I lack any power to protect myself, other than the power of my knowledge. I welcome corrections or additional commentary from anyone out there with more knowledge than myself.
Global jetstreams were extensively mapped during World War II and the Cold War. The military initially tracked these high atmospheric wind patterns to determine the optimal bombing patterns over Europe and Japan during the war. After the war, when close to 1000 atomic bombs were detonated at the Nevada Test site between 1951 and 1992, the military wanted to know how and where radiation could spread. Jets and weather balloons were sent to track radioactive particles from the bomb tests, and voila—it turned out that fallout was spreading everywhere, once it entered a jetstream. (A jetstream exists between the troposphere and the stratosphere, i.e., about 23,000-52,000 feet above sea level. They affect our climate in many ways. The infamous El Nino and La Nina weather patterns are caused by changes in jetstream activity that interacts with ocean currents.)
Atomic fallout easily enters the jetstream because of the power of each explosion. My understanding is that the reactors in Japan cannot explode with that kind of force, which minimizes the possibility of interaction with global jetstreams. However, I have not yet seen anyone discussing it from that angle. Instead, we have been given an utterly ridiculous talking point from the nuclear industry, that radiation cannot spread beyond certain distances, as if there were some kind of built-in force preventing it from doing so. This line is preposterous, and I’m going to show you why.
In 1979, President Jimmy Carter was persuaded to begin declassifying certain documents from the atomic testing program. During the 1980s, historians began publishing books based on the information they found in those documents. What they found was very worrisome. It turns out that nuclear scientists knew all along that fallout from both American and Soviet testing was traveling around the globe and creating random “hotspots” of deadly radioactivity. That information was not shared with the public.
Below is a map created by historian Richard Miller, who examined a whole slew of declassified fallout maps. Miller aggregated the data from those maps and created his own map showing where fallout clouds passed more than once during the years of aboveground testing, 1951-1962. As you can see, most of the United States was covered at some point by a radioactive cloud during those years. (Southern California escaped because the scientists avoided setting off bombs when the wind was blowing in that direction. That’s a whole ‘nother story, as they say.) The United States is about 3300 miles from west to east. The clouds had no problem whatsoever traveling that distance. Even more importantly, the fallout traveled beyond our borders, although we didn’t bother tracking it once it passed into other nations’ territory. (Or if we did, those documents have not yet been released.)
Okay, I can't see the actual image in my "Preview" page, so I'm going to post the Flickr link:
Miller Fallout Chart
Miller also found that when the fallout clouds met precipitation, radiation fell to the earth. Thus there were hotspots that we know about in Nevada, Utah, and Idaho, of course, but also in upstate New York, in Texas, and in Missouri. We only know about these hotspots because universities and other researchers in those areas happened to have their Geiger counters turned on at the time. The government did not share that knowledge with us; it was independent researchers who established the fallout in their local regions. Residents could have avoided harm from that fallout if they had been advised to stay inside during those storms. They were not so advised.
Another startling fact from Miller: 1963 was the most radioactive year in history around the globe. For the United States, the summer of 1963 was particularly deadly. Due to heavy testing by both the Soviets and the U.S. during the previous two years, “literally tons of radioactive material were hurled into the stratosphere” and was beginning to fall back to earth in a fine, invisible dust.
Keep in mind that the last aboveground test in the U.S. occurred in November 1962, while the last Soviet test occurred on December 25, 1962. In the last months of 1962, multiple bombs were exploded daily on both sides of the globe, because scientists knew a test ban treaty was on the horizon (in August of 1963, the treaty was signed). Over the next six months, that fallout circled the globe and arrived on the ground. In September 1961, Miller says, the average New Yorker’s daily intake of strontium-90 was 2.6 picocuries. One year later, it was 5.6 picocuries, and by February 1963, it was 18.4 picocuries. Chicago and San Francisco showed similar rises during those two years. Strontium-90 collects in the bones and causes deadly cancers down the road, instead of immediately.
The fallout did not arrive at the same rates in every area, though. For example, Miller points out that in July 1963, Seattle received only 1/10th the amount of strontium-90 that Westwood, New Jersey received. Other radioactive elements also fell to the earth during that summer, including manganese, antimony, tellurium, radioactive iron, cesium 137, and plutonium (one of the most carcinogenic substances known).
Much of what fell in the U.S. actually originated halfway across the globe, in the Soviet Union, a full six months earlier.
In the Midwest in 1962, an enormous level of 536 picocuries of cesium-137, and 138 picocuries of strontium-90 was found in each kilogram of the Iowa wheat crop. That led to fairly high levels of radioactivity found in bakery products in New York City, San Francisco, and Chicago the following summer.
During the 1950s testing period, government researchers also knew that Iodine-131 was entering the American milk supply at alarming levels. Iodine-131 has been definitively connected to thyroid cancer, which is perhaps the most common form of cancer resulting from fallout. In 1953, children living in southern Utah might have received doses as high as 120 to 440 rad. In 1966, children across the nation were found to have elevated levels of Iodine-131 from drinking contaminated milk—15 rad as far away as Albany, New York. Between 1959 and 1962, state officials in Utah and Minnesota found such high levels of Iodine-131 in their milk products that they decided to remove their milk from the marketplace. Federal officials refused to allow them to remove that milk, after deciding that radiation guidelines did not apply to fallout materials (!!). Diverting milk from the market could cause “malnutrition,” one scientist testified. A study done in 1977 found that the rate of thyroid cancers across the nation had increased by 62% between 1969 and 1971. The National Cancer Research Institute estimates that between 10,000 and 75,000 cases of thyroid cancer will be related to fallout, and only 30% of those had been diagnosed as of the mid-1990s. Virtually everyone living in the U.S. between the 1940s and the 1960s was exposed to excess Iodine-131. Children under 15 were most at risk.
In 1997, Dr. Joseph Lyon—a medical researcher at the University of Utah School of Medicine, who conducted multiple epidemiological studies regarding the rates of thyroid cancer and leukemia among southern Utahns—testified before Congress that he had been forced by government officials at the Department of Defense and the Department of Energy to alter his findings before he was allowed to publish them. In other words, the government forced him to revise his data downwards to show a reduced rate of cancers in the Utah population. Dr. Lyon noted that if a graduate student had done this to his data, he would have been failed out of school. (BTW, Lyon found a 7x increase in leukemia among children in southern Utah. In at least one case since then, Dr. Lyon was approved for a grant to do a follow-up study, but someone in government intervened and removed the funding at the last minute.
Thus history tells us at least two things about the current situation:
1) Radiation can indeed spread around the globe if the conditions are right.
2) The government is not likely to tell us when that happens.
Don’t panic, don’t obsess. Just be informed. Based on my research, my advice is to avoid going outside during any kind of precipitation for the next few months or so. Children and pregnant women are especially vulnerable. Thoroughly wash all your produce for five minutes under running water. Wear a mask or scarf over your mouth on dusty or windy days. And spread the word.
Suggested reading:
Richard Miller, Under the Cloud: The Decades of Nuclear Testing (New York: MacMillan, 1986).
Barton Hacker, Elements of Controversy: The Atomic Energy Commission and Radiation Safety in Nuclear Weapons Testing, 1947-1974 (Berkeley: University of California Press, 1994).
Howard Ball, Justice Downwind: America’s Atomic Testing Program in the 1950s (New York: Oxford Univ. Press, 1986).
Pat Ortmeyer and Arjun Makhijani, “Worse Than We Knew,” The Bulletin of the Atomic Scientists, Nov-Dec 1997.
Updated by HPrefugee at Wed Mar 16, 2011 at 11:52 AM MST
UPDATE: As several commenters have pointed out, I've been reading too much early history on radiation and I got the science wrong. There are nuclear isotopes (not alpha/beta/gamma particles) which made it into the jetstream during atomic testing, then fell to the earth many months later, where they were found and measured as still highly radioactive by scientists, and emitting alpha/beta particles and gamma rays. Some of those isotopes were found to have come from Soviet bombs, halfway across the globe and from six months earlier.
My overall point stands: IF the Fukushima fallout gets into the jetstream, it will carry around the globe. But we will not know if it gets into the jetstream, because the government will not tell us.
Also, at least one article from the atomic testing era indicates that the farther away you get from the source of the fallout, the more concentrated the radioactivity will be, because smaller particles travel farther and will hide in plant crevices better. The lesson is to wash your produce thoroughly.