The tables in this centerfold show fallout data and estimated doses from the testing of nuclear weapons in the atmosphere. The fallout data for various radionuclides and resulting doses estimates were published by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). IEER calculated the fatal cancers that would result from these doses to the global population based on fatal cancer risk estimates published by the fifth report of the committee on the Biological Effects of Ionizing Radiation (BEIR V) of the U.S. National Academy of Sciences.

The centerfold table shows fatal cancers as they would be calculated directly from the risk estimates as published in BEIR V, without any adjustments. It is common regulatory practice to adjust the fatal cancer risk estimates downward by about a factor of two for doses that are delivered slowly over long periods of time (as is the case with global population doses from fallout). The reduction is based on the hypothesis that low doses and low dose rates are less effective in producing cancer per unit of dose than high dose rates. Except for leukemia, this assumption is based mainly on animal data. These data could justify the use of various dose rate effectiveness factors (DREF) and BEIR V does not explicitly recommend a specific one to use. The U.S. Environmental Protection Agency had the Nuclear Regulatory Commission use a factor of 2, noted above. This hypothesis is not universally accepted, however. Many believe that doses delivered at low dose rates are at least as effective if not far more effective in producing cancer as higher dose rates (per unit of dose). Fatal cancers estimated using such methods would be far higher than those presented in the centerfold.

Since there are considerable uncertainties in the area of low dose estimation, it is IEER practice to use unadjusted BEIR V risk coefficients for fatal cancers, which are the most authoritative published ones (though how they will compare to the ones that will eventually be considered precise is unknown at this time). We also normally describe the effect of using a DREF of 2. Note that the official estimates of the cancer risk of low-dose radiation have generally tended to increase over time.

The use of a DREF of 2 would reduce all cancer estimates in the centerfold by a factor of 2. The total estimate for all fatal cancers through the next century from doses committed through the year 2000 would be about 215,000 (compared to 430,000 in the Table). There are considerable uncertainties in both of these figures (several-fold on either side).

The centerfold also shows fatal cancer estimates extending out to all time -- that is it includes all doses for all radionuclides until they are completely decayed away. These long-term doses come mainly from carbon-14, which was created in the atmosphere from neutron bombardment of nitrogen during atmospheric nuclear explosions. This carbon-14 exists as radioactive carbon dioxide gas in the atmosphere; it is mixed with naturally occurring carbon-14. It enters our food chain through the photosynthesis process and due to its long half-life (5,730 years) dominates the dose over the long term. The total, rounded to one significant figure, using unadjusted BIER V risk coefficients is about 2.4 million fatal cancers. With a DREF of 2, the total would be about 1.2 million fatal cancers.

Note that even with such very large numbers of cancers, it is essentially impossible to attribute any specific person's cancer to testing because there are so many more cancers from other causes, and because the increased risk to any one individual from fallout is comparatively low. (This does not apply to certain groups that were more highly exposed, such as many workers in nuclear weapons plants or downwinders).

The centerfold also shows IEER's estimates of radioactivity left underground due to underground nuclear weapons testing. These figures are for decay-corrected radioactivity. This means that we have adjusted for the decay of radionuclides. While plutonium-239 (half-life over 24,000 years) and carbon-14 have not yet decayed significantly, cesium-137 and strontium-90, both with half-lives of about 30 years have decayed substantially.

It was claimed by the nuclear establishment that the contamination from underground testing would be neatly contained in glassy material created out of the molten rock resulting from the intense heat of the underground nuclear explosion. There is, however, no basis in measurements to claim that essentially all the radioactivity has been contained in this way; in fact there is some clear evidence to the contrary. In any case, it is noteworthy that the DOE does not believe it can even begin to address the clean-up of the severely contaminated underground environment of the Nevada Test Site. In its recent report on "baseline" costs of clean-up of the weapons complex, the DOE did not even attempt to put a figure to what it might cost to clean-up after the underground testing program. Thus, in practice it is clear that the DOE is admitting that the contamination is not sitting there in a neat glassy blob for someone to retrieve at low or even moderate cost. It does not even know how to begin to address the problem of this contamination, so far as one can tell from its cost assessment.

In sum, the shift of testing underground in 1963 after the U.S.-Soviet-British treaty banning atmospheric tests, drove the problem out of sight (for the most part) but did not eliminate it.

The centerfold is derived from the book on nuclear weapons testing prepared by the International Physicians for Prevention of Nuclear War and IEER, entitled Radioactive Heaven and Earth, published by Apex Press, New York, 1991. The book is $17, and is available through IEER.

Institute for Energy and Environmental Research

Comments to Outreach Coordinator: ieer@ieer.org
Takoma Park, Maryland, USA

Last updated: August, 1996