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| Fig. 1: An abandoned building in Chernobyl. (Source: Wikimedia Commons) |
In 1986, a nuclear reactor accident at Chernobyl resulted in one of the worst nuclear fallout disasters in history. While a Chernobyl Exclusion Zone was defined in which no inhabitants can live (except for 300 who refused to leave), the nuclear fallout travelled to many countries surrounding Ukraine. [1] Scientists have been greatly concerned about the potential increase in cancer in communities affected by Chernobyl. Now that it has been over 25 years since the incident, scientists are starting to gather good data on how those affected by the accident have been impacted by the radiation compared to unaffected individuals as controls. Scientists are also able to correlate the effect of the radiation by comparing patients based on their distance from the blast.
Many reports support an increase in various forms of thyroid cancer incidence in adolescents who were exposed to the post Chernobyl radioactive fallout, as well as a potential increase in leukemia incidence. In 2012, a Conference on Radiation and Health took place in Kennelbunkport, Maine, where many scholars discussed new data surrounding the relationship between the Chernobyl accident and cancer incidence. Dr. Lydia Zablotska from UCSF linked an increase in both Chronic Lymphatic Leukemia (CLL) and non-CLL in Ukranian workers who helped with the Chernobyl cleanup between 1986 and 1990 and long term exposure to low level radiation. Dr. Michael Abend from the Bundeswehr Institute of Radiobiology in Germany identified several gene candidates that can result in thyroid cancer after exposure to I-131 radiation released after the Chernobyl accident. [2]
Also at the 2012 Conference on Radiation and Health, Dr. Mark Little from the United States National Cancer Institute released startling data suggesting the flaws in data collection of many radiation studies. As an example, Dr. Little used a study showing thyroid cancer incidence in adolescents exposed to radiation fallout from Chernobyl. Dr. Little discusses that studies like this often have classical errors and Berkson errors. Classical errors are defined as data collected under the assumption that they all deviate with independent error from the true result, which would cause "a downward bias in the dose-response parameter." Berkson errors are defined as data collected where the true dose is randomly distributed around a measured estimate. Berkson errors cause no problem with linear models, but disturb the results of non-linear data sets. Dr. Little argues that these errors play out in the extrapolation of data to high or low radiation doses, and predicts that the regression of the thyroid study in adolescents mentioned above may be off by 5-14%. [2]
The accident at Chernobyl, even 28 years later, may still affect the lives of those exposed to its radioactive fallout. Current data is conflicting and filled with political bias. If we choose to believe the many studies suggesting Chernobyl fallout increased cancer incidence, most show minimal effects on patients. Thyroid cancer, which seems to be the most studied and correlated cancer incident from Chernobyl, is extremely treatable and has a very low mortality rate. [3] Continued research as the years go by will help us determine once and for all the actual long term effects of the accident. Unfortunately, it will be another 19,972 years before the Chernobyl Exclusion Zone is deemed habitable. [1] As so, it will serve as a constant reminder for 19,972 years of the immense power and capability of nuclear energy gone wrong.
© Nathan Barnett. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] K. Knauer, Disasters that Shook the World: History's Greatest Man-Made Catastrophes, (Time Home Entertainment, 2012).
[2] P. Jacob and D. O. Stram, "Late Health Effects of Radiation Exposure: New Statistical, Epidemiological, and Biological Approaches," Int. J. Radiat. Biol. 89, 673 (2013.
[3] M. Sokouti et. al, "Thyroid Cancer, Clinical and Hystopathological Study on Patients Under 25 Years in Tabriz, Iran (2000-2012)," Pak. J. Biol. Sci. 16, 2003 (2013).
