Journal of Cancer Research and Therapeutics, Vol. 7, No. 2, April-June, 2011, pp. 109-111
Chernobyl, Fukushima, and beyond: A health safety perspective
ACTREC, Tata Memorial Centre, Navi Mumbai- 410210, India
Code Number: cr11027
It is truly unfortunate that the Fukushima tragedy was to happen in the 25 th year of the Chernobyl disaster. Just as the dust was settling and the scientific world was in the process of bringing out a mature narrative of the long-term health effects of Chernobyl, the fury of nature resulted in another nuclear accident at Fukushima. If Hiroshima and Nagasaki are unthinkable and buried in the deepest recess of human shame, Chernobyl and Fukushima have kept the fear alive. In light of the Fukushima accident, the International Atomic Energy Agency (IAEA) and its member states are re-examining the safety of the existing and future nuclear technology.
What truly is the risk of nuclear accidents and the associated health hazards? Is the reality closer to the calculation of safety experts and governmental agencies or to the speculation of the common man and nongovernmental agencies? In the backdrop of nuclear accidents and the way Chernobyl was initially handled, opponents of nuclear technology are always reading between the lines and fearful of a shroud of secrecy. The proponents on the other hand try to circumvent obstacles from what they consider as ill-informed laity, led by an amorphous group of intellectuals, politicians, social scientists, and academicians. As medical specialist users of ionizing radiation, it is important for us to understand public concerns with radiation safety which is bound to be heightened after nuclear accidents. Our inputs could also bring a greater understanding of health hazards from radiation within the scientific community and we are best placed to engage members of the public for genuine concerns or misconceptions they may have regarding radiation, especially low-dose radiation and medical uses of radiation.
The health risks due to radiation exposure and the causality can be ascertained only through long-term and detailed radiobiological and epidemiological studies. There are some well-defined time- and dose-dependent health hazards of radiation such as acute radiation sickness, cataracts, thyroid cancer, and leukemia. The challenges in establishing or refuting a causal relationship between radiological accidents and some common multifactorial health conditions give rise to exaggerated fears even among medical professionals. Discussing the fears, rumors, and truths about the health effect of Chernobyl, Mati Rahu, an Estonian epidemiologist, has invoked the Allport and Postman′s basic law of rumor.  This law postulates that the circulation of a rumor is roughly equivalent to the importance of the rumor to the person who hears or reads it multiplied by the uncertainty or ambiguity surrounding the rumor. Unfortunately, the inherent fear of radiation has been compounded by the paucity of a scientifically valid yet simple uncluttered narrative of the adverse effects of radiation, finding its way to the common man.
The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) through a series of reports on Chernobyl, the first of which appeared in 1988, gives a detailed account of the health effects of radiation exposure after this accident.  The WHO media center has also presented a comprehensive, unbiased, and lucid account of the health effects of Chernobyl, well suited for members of the public as well as for the professionals who are not familiar with the language of radiobiology or epidemiology.  The WHO report is based on the series of WHO expert group meetings that reviewed all scientific evidence of health effects of the Chernobyl accident in the first 20 years. To mark the 25-year period after Chernobyl, the IAEA website has a series of 25 stories presented through photographs and videos which capture the essence of environmental, societal, and health impact of Chernobyl.  Narratives of human experiences from organizations which many of us perceive as multinational super bureaucracies and technocracies reassure our faith on global mechanisms reaching out to the global community. The Royal College of Radiologists has brought out a special issue of its official journal - "Clinical Oncology" - in May 2011 with Gerald Thomas as its Guest editor. This special issue titled "The radiobiological consequences of the Chernobyl accident 25 years on - April 2011" makes a significant contribution by bringing out a detailed account of the physical and psychological health impact during 25 years of the Chernobyl disaster.
The explosion on April 26, 1986, at the Chernobyl nuclear power plant resulted in the largest ever environmental release of radionuclides from a civilian operation and this was deposited over large areas of Belarus, the Russian Federation, and Ukraine. The main radionuclides responsible for a health impact were Iodine-131 (half-life 8 days), Cesium-134 (half-life 2 years), and Cesium-137 (half-life 30 years). Several hundred thousand "liquidators" from the nuclear establishment, army, and local agencies were marshaled by the USSR regime to clean up or contain the radioactive mess in and around Chernobyl. The UNSCEAR report shows that of the 600 workers present on the site during the early morning of April 26, 1986, 134 received high doses of radiation ranging from 0.8 to 16 Gy and suffered acute radiation syndrome. Within the first 3 months of the accident, 28 of these brave men died from radiation exposure. Another 19 died during the period 1987-2004 due to different causes, not necessarily associated with radiation exposure.
Within months of the accident, 116,000 citizens were evacuated to noncontaminated areas and another 230,000 were relocated in subsequent years. Five million people continue to live in contaminated areas with low radioactivity levels of Cesium (37 kBq/m 2 ) and a quarter of million people continue to live in areas classified by Soviet authorities as strictly controlled zones where the radioactive contamination exceeds 555 kBq/m 2 .  The WHO expert group has estimated the average effective dose accumulated over a 20-year period for different groups, and compared it with the average natural background radiation of 48 mSv over 20 years and that from medical exposure such as a whole-body CT scan which gives a dose of 12 mSv. The average total dose over 20 years was estimated to be >100mSv for the 240,000 liquidators, >50 mSv for the 270,000 residents of the high-contamination zone, >33 mSv for the 116,000 evacuees, and 10-20 mSv for the 5 million residents of the low-contamination zone. Children of various ages including those who were in utero received significant radiation exposure, primarily to the thyroid gland, from consuming milk contaminated with radioactive iodine.
After the unfortunate initial fatalities from acute radiation sickness, the most significant health impact of Chernobyl was the huge surge of thyroid cancer in over 5000 children exposed to the radiation after the Chernobyl accident.  There is also a suggestion of an increased risk of nonthyroid malignancies such as leukemia and breast cancer in the radiation-exposed groups but it requires confirmation in well-designed epidemiological studies. Tuttle et al. have examined the existing data on post-Chernobyl pediatric thyroid cancers.  They report that despite short-term disease recurrence rates of 7-28%, the projected 30-year disease-specific mortality is extremely low at 1%. This would result in 50 deaths from pediatric thyroid cancers over 30 years. In order to understand how radiation causes thyroid cancers and to understand the behavior of this cancer, through multinational collaboration a unique resource has been created in the form of the Chernobyl Tissue Bank.  The Chernobyl data also provide clear evidence for early stage cataracts, specifically, the posterior subcapsular cataracts with threshold radiation doses that otherwise are considered safe in current radiation protection guidelines. 
The impact of Chernobyl cannot be measured only by cancers and cataracts. It left a deep psychosocial impact on the affected population. The sense of loss and broken social networks was accompanied with the social stigma of being an "exposed person." Lack of reliable information among people in the first few years resulted in widespread mistrust and false attribution of many health problems to radiation exposure. Diminished facilities for health care, excessive smoking, and drinking that accompanied the dissolution of the Soviet Union all contributed to the reduced average life span in the Chernobyl-affected countries. While we always focus on human health and mind, I could not find any authentic account of what happened to the thousands of pets that would have been left behind in haste, with their furs full of radioactive contamination.
Gluzman from the Ukranian Psychiatric Association  provides another insight in the role of medical academia in interpreting and exploiting such tragedies. He describes how the pendulum swung from the initial secrecy during the Soviet regime to the hyperbole in the newly independent Ukraine. The Ukrainian Chief Psychiatrist of the Ministry for Health Protection declared that 30% of the Ukrainian population ran the danger of dementia from low-dose radiation. Gluzman appreciates that unlike some medical professionals, the sociologists in Ukraine demonstrated common sense and scientific impartiality. However, they published in specialized journals which never reached the public and could not influence public opinion. Ukrainian sociologist Natalia Panina denounced the phenomenon of "radiophobia" which she defined as a deliberate attempt to interpret the normal and natural fear experienced by many humans under conditions of lack of information as being the result of a pathological process. Gluzman finishes his personal perspective by expressing anguish that none of the Ukrainian pseudoresearchers who speculated on various parascientific myths were divested of scientific titles and high managerial positions which came to them based on their astounding declarations and findings in the Chernobyl aftermath.
Even though the scale of radiological events at Fukushima is nowhere comparable, it reminds of Chernobyl in so many ways. While the response was swift and well organized and the global citizens were kept well informed, Fukushima accident has had a serious impact on the public confidence in nuclear technology. The IAEA International Fact Finding Expert Mission visited Fukushima in the last week of May 2011. In their preliminary report,  they have lauded the Japanese government, nuclear regulators, and operators for being extremely open in sharing information and answering many questions to assist the world in learning lessons to improve nuclear safety. The IAEA has also appreciated the extremely well-organized evacuation and the Japanese Government′s long-term response to protect the public. The exemplary response at the accident site by the dedicated staff of the nuclear establishment and the emergency rescue staff was lauded by the entire world and made famous by the media as the valiant Fukushima Fifty. While health effects have not been reported in any exposed person as yet, health monitoring and follow-up programs for the public and radiation workers who may have been exposed to various levels of radiation are warranted.
To address heightened public awareness and unease over radiation safety after the Fukushima, we need to draw many lessons from Chernobyl. Ionizing radiation is our professional tool that we painstakingly learn to safely harness for improving human health. It is also our duty to understand and respond to natural fears people may have regarding radiation, especially its medical uses and low-level radiation. This open access journal of our National Association of Radiation Oncologists could serve as a platform for professionals in Radiology, Radiation Oncology, Nuclear Medicine, and Radiation Biology to engage with nonradiation medical professionals, public, and also the policy makers on the real and imaginary health hazards of radiation.
Copyright 2011 - Journal of Cancer Research and Therapeutics