Low-dose Extrapolation of Radiation-Related Cancer Risk

Draft document: Low-dose Extrapolation of Radiation-Related Cancer Risk
Submitted by Blaine N. Howard, none
Commenting as an individual

The Executive Summary (page 9) states: “These reports (by UNSCEAR and NCRP) recommended that radiation protection continue to be guided by the LNT hypothesis. The task group concurs with those recommendations.” I ask you to reconsider this decision. Since the BEIR report in 1972, the LNT has been used and misused to justify the continual tightening of regulatory controls. It has also been misused by questionable scientists to predict the numbers of cancer deaths as a result of large population exposures to small amounts of radiation. These predictions have scared a lot of people and caused a lot of needless worry. This is a practice which is specifically forbidden by the Health Physics Society. It is easy to see why Dr. Lauristen Taylor referred to such predictions as "deeply immoral uses of our scientific heritage". It was introduced as a servant and has become the master. When the LNT was introduced, the biological response to low doses (less than 200 mSv) was not well understood. Now we have statistically valid evidence that LNT fails very badly in several studies. 1.The Nuclear Shipyard Worker Study. Formally titled “Health Effects of Low-Level Radiation in Shipyard Workers” this study was conducted under DOE Contract Number: DE-AC02-79EV10095 by The Johns Hopkins University; Department of Epidemiology. The Principal Investigator was Genevieve M. Matanoski, M.D., Dr.P.H. And professor of Epidemiology at The Johns Hopkins School of Hygiene and Public Health. The study was well designed to compare shipyard workers who were exposed to and monitored for ionizing radiation in the course of their work to other shipyard workers who performed similar work but were not exposed to ionizing radiation in the course of their work. This was so designed to eliminate any so called “Healthy Worker Effect”. The study was watched carefully by a Technical Advisory Panel (TAP), who reviewed the work at least twice a year and approved the Final Report which was completed in June 1991. The TAP was composed of 8 eminent scientists. One of these scientists was Dr. Merrill Eisenbud, Professor of Environmental Medicine at the New York University Medical Center. I have worked very closely with Dr. Eisenbud and know him to be a man of unquestionable integrity and the other scientists were of similar integrity. The results of this study showed that the group of nuclear workers receiving over 0.5 rem had a standard mortality ratio (SMR) of 0.76 compared to 0.81 for radiation workers receiving less than 0.5 rem and 1.00 for the non-nuclear workers. These numbers are statistically significant and demonstrate without doubt that the LNT fails in this case. I believe the ICRP members are well aware of these facts and can not understand why they choose to ignore them. IT IS DIFFICULT TO UNDERSTAND WHY THIS STUDY WAS NOT EVEN MENTIONED UNDER OCCUPATIONAL STUDIES ON PAGE 35. 2.Dr. Bernard L. Cohen's “Test of the linear-no threshold theory” in which he correlated the lung cancer mortality data with average measurments of radon in homes county by county. The obvious negative relationship has baffled the U.S. Environmental Protection Agency for many years, but they refuse to accept the results. Certainly the ICRP members have heard of this study. 3.More recently a study of “Cancer mortality among French Atomic Energy Commission Workers” which compared both all causes and cancer mortality of 58,320 workers with that of the general population in a retrospective cohort study showed a “healthy worker effect”. The SMR for men was 0.57 and for women was 0.72. Nine sites of cancer death were found to be in statistically significant deficit among men. See (Am. J. Ind. Med. 45:34-44, 2004) 4.An additional study of “Mortality of workers exposed to ionizing radiation at the French National Electric Company” consisted of 22,395 individuals monitored for radiation exposure between 1961 and 1994. Conclusion: “Our study demonstrates a clear healthy worker effect (HWE) since mortality is less than half what is expected from National mortality statistics.” The SMR was really 0.48 and 0.58 for cancer. See (Am. J. Ind. Med. 47:72-82, 2005) This “Healthy Worker Effect” seems to be a marvelous thing. Don't you think that a factor of 2 in the French studies is a little high? Is there still room for an increased cancer mortality hidden in these studies. Isn't it more reasonable to accept a threshold or even a beneficial effect as being demonstrated by these studies? What I am trying to point out is that there must be some “reasonable doubt” established by these and many other studies which show similar results. Enough doubt that the ICRP task group members might question whether the aparently emotional attachment to the LNT is worth the huge costs and negative effects of hanging on to the failed “hypothesis”. Some of these costs are: 1.The continual lowering of radiation exposure limits causes the costs of operating nuclear power plants to escalate. 2.The associated FEAR of radiation in any amount has infiltrated the political community and no one seems willing to become host to a spent nuclear fuel repository. 3.Because the anti-nuclear sentiment has become so wide spread and the difficulties associated with spent fuel disposal, the power companies are not ordering new nuclear power reactors and we can see a possible end of the nuclear power industry. 4.Without the general fear of radiation, the “dirty bomb” would have no power. 5.The tremendous fear of being harmed by radiation causes people to make bad choices. An example of this occurred during the Chernobyl disaster. Consider the following quote from the Journal of Nuclear Medicine. “In many countries in western Europe, legal abortions increased for several months following the Chernobyl accident probably because of fear of the effects of the radioactive fall-out .....; according to the IAEA, 100,000 to 200,000 excess abortions were performed throughout western Europe after the Chernobyl accident.” (Ketchum, L.E. (1987) Lessons of Chernobyl: SNM members try to decontaminate world threatened by fallout, Part I [Newsline]. J. Nucl. Med., 28, 413 422. ) In addition to the hundreds of thousands who were evacuated and relocated, many thousands of unnecessary abortions were performed. Can you imagine the terror of an expectant mother who, because of fear of giving birth to a horribly deformed baby, chose an abortion? They were terrified. Then multiply this by many thousands and get a glimpse of the horrors perpetrated by teaching LNT to be true. I believe that this is the most horrendous of all the negative effects of believing in LNT. There are other costly negative effects such as the expenditure of billions of dollars in cleaning up (decontaminating) trivial amounts of radioactivity, but the ones I have mentioned are enough to consider. When I gave training lectures to new employees, I told them “If the effect of low dose radiation is so small that the experts can't agree on whether it is harmful, beneficial, or even exists, it is too small to worry about”. Will you please let the world know that low levels of radiation are not a significant threat and that there is a safe level of radiation. I find people in Utah concerned about the risk of living within 1 mile of a railroad which could carry a shipment of spent nuclear fuel. I am concerned that people worry too much. They have not understood the trivial nature of such extremely small radiation levels. Certainly, a the belief in LNT and that the tiniest amount of radiation may cause cancer has had some impact on this unfounded fear. I ask you individually to search your souls and ask “Is it worth it”. How can you cling onto a “hypothesis” which has been demonstrated to be false and extremely harmful with an almost religious fervor? I challenge you to express some courage and make a break with the improper decisions of of the past and make a decision to modify the model to eliminate the no threshold part.. The model should be modified to reflect the fact that risk of harm should only be anticipated at doses which have been demonstrated to cause real (and not theoretical) harm. Will you at least make a statement that can influence the public, the politicians and news media to stop worrying about effects which are completely negligible. Sincerely, Blaine N. Howard, Health Physicist (retired)