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International Network of Engineers and Scientists Against Proliferation |
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International Network of Engineers and Scientists Against Proliferation |
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Wolfgang Koehnlein, Rudi H. Nussbaum 
Excerpts from: Medicine and Global Surival, Vol.5, No.1, January 1998, pp. 14-21; introduction and conclusions reprinted with permission. The original article includes an extensive list of literature.
Proponents of a practical threshold for radiogenic risk have ignored epidemiological findings of excess cancers among workers and have generalized about the effects of high doses from in vitro studies of DNA repair mechanisms. Aggregate studies of occupational exposures and of children x-rayed in utero show that the proposition of a safe dose range or dose rate is false. The repair system of the mammalian cell is never perfect. Epidemiological studies of exposed persons that have been accepted in the scientific literature show a statistically significant increase in cancer incidence in the exposed population, supporting the claim that very low doses cannot be regarded as safe with respect to cancer induction.
Ionizing radiation from external sources, and the biological effects of such radiation, have been studied for more than a century. While acute health effects (e.g., burns, nausea, hair loss, bleeding, etc.) occur only at high-dose exposures, various official radiation commissions now generally accept that delayed detriment due to mutations in the cellular DNA has been established at low doses, down to about 20 cSv (rem) for adults and less than 1 cSv for fetuses.
These mutational (or stochastic) biological effects, in which the level of dose determines the level of probability or likelihood of occurrence of the effect, can lead to initiation or promotion of malignancies (somatic effects such as cancers and leukemia) or to genetic defects in subsequent generations.
Some recent reviewers of radiation health effects have asserted the existence of an "effective" or "practical" threshold for radiogenic risk below about 10-20 cSv. In doing so, however, they have:
Conclusions
Combining the known mechanism of low-LET interactions in human cells with findings from several independent epidemiological studies clearly shows that the repair system of the mammalian cell is imperfect and that there is no harmless dose threshold.
This conclusion, drawn from the aggregate of scientific evidence, has complex ethical, economic, and political implications for continuing radioactive contamination of our soil, water, and atmosphere. The following two facts have to be faced:
1. There exists no confirmed or scientifically reliable method of ascertaining permanent isolation of radioactive wastes from the biosphere (measured in geological time spans).
2. Future statistically predictable reactor accidents, such as Chernobyl, will add worldwide somatic and genetic health detriment.
From this perspective, the authors deem continued application of nuclear technology for energy production, whether in the U.S. or as an export to developing nations, a violation of the fundamental spirit of the Universal Declaration of Human Rights.
How should the application of nuclear technology be managed and are there viable alternatives?
As radiologists and physicians in general become better informed about the lack of any risk-free threshold and about the magnitude of radiogenic risks, they will and should opt to minimize the use of radiation in diagnostic and therapeutic procedures. The saga of the early embrace of x-raying pregnant women and the ultimate warnings against such a procedure can serve as an object lesson. It is essential, however, that physicians include better informed patients in meaningful risk-benefit assessments.
The argument is now being made by the nuclear energy industry and its government and corporate supporters that nuclear energy generation is the only solution to forestall global warming. Studies by respected scientists, however, have shown that energy conservation, using state-of-the-art improvements in the efficiency of energy-driven devices, combined with the development of community-based alternative energy technologies including solar power, wind, biomass, and fuel cells, can meet the energy needs of both developed and developing nations. In addition, these technologies can also provide employment in both small and large enterprises, including jobs for those with advanced technical skills who presently work in the nuclear industries.
What is needed is a well-integrated policy that must include a reordering of national priorities. Such redirection of the enormous public and private resources presently invested in industries responsible for polluting the earth with chemicals and radiation can only be brought about by the effective commitment of informed citizens.
Wolfgang Köhnlein is Professor and Director, Institute for Radiation Biology, University of Münster, Germany. Rudi H. Nussbaum is Professor Emeritus of Physics and Environmental Sciences, Portland State University, Portland, OR USA. Address correspondence to: Wolfgang Köhnlein, Robert-Koch-Strasse 43, 48129 Münster, Germany; e-mail: kohnlei@uni-muenster.de; or Rudi H. Nussbaum, Portland State University, Portland OR 97205-0751 USA; e-mail: d4rn@odin.cc.pdx.edu.
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