Radiation-induced Childhood Thyroid Cancer After the Chernobyl Accident

Hanna Chang
February 20, 2017

Submitted as coursework for PH241, Stanford University, Winter 2017

Introduction

Fig. 1: Chernobyl Exclusion Zones (Souce: Wikimedia Commons)

Known as one of the most destructive nuclear accidents in the world, the Chernobyl accident occurred in Ukraine on April 26, 1986. Following the desctr Severe radioactive poisoning of the atmosphere occurred as radioactive materials were released into the atmosphere following several events: steam explosion and fire at the power plant. As a consequence, large portions of Belarus, Ukraine, and the Russian Federation were affected by the contamination of water and food due to the fallout. [1] Fig. 1 shows an exclusion zone from the Chernobyl accident. Due to this incident, there was a dramatic increase of childhood thyroid cancer cases and its serious reality has affected the lives and health of many children up to this present day.

Radiation-Induced Thyroid Cancer

There are many underlying evidence that underline the continuation of thyroid cancer in Ukraine. A comprehensive genomic study led by Dr. James A. Fagin analyzes the serious reality of the Chernobyl accident by highlighting the thyroid cancer cases and increased risks from the nuclear accident. According to Dr. Fagin, "it is estimated that more than 6,000 cases of thyroid cancer were caused by the disaster". [2] The radioactive material that affected the lives of the Ukraine population was mainly composed of iodine isotopes, in particular I-131.

In the affected areas of the nuclear accident, children under the age of 10 were at a higher risk of getting thyroid cancer, because they were more likely to consume dairy products and maternal milk that were contaminated by radioactive iodine. The thyroid gland is where the radioactive iodine gets easily collected. [1] The accumulation of radioactive iodine led to DNA breaks and genomic changes, leading to the formation of malignant and benign tumors in the thyroid gland. [2]

On a regular basis, the risk of getting children thyroid cancer is extremely low, "with less than one new case per million diagnosed each year". [3] However, in the case of the Chernobyl accident, around 1.4 percent of the exposed population was diagnosed with thyroid cancer. [3] Furthermore, studies by researchers have supported this idea by demonstrating that there were cases where the latency period for thyroid cancer was as long as 69 and 58 years after radiation exposure. [4] For these reasons, it is difficult to overlook the correspondence between the Chernobyl accident and its impact on the diagnosis of childhood thyroid cancer.

Conclusion

Although there are some convincing evidence suggesting the correspondence of the Chernobyl accident and its direct impact of thyroid cancer, the short-lived nature of radioactive iodine and the latency of the radiation-induced cancer make scientific measurements uncertain and ambiguous. Affected areas of the Chernobyl accident are facing socio-economic crisis. The distrust and social stigma that stem from the idea of contamination have impacted the economy of affected areas, as people left the areas and the government faced the immense cost of cleanup. [5] In the face of socio-economic crisis, scientific researches on Chernobyl's health effects are scarcely funded. For better improvement of the health for future generations, more scientific research on the Cherynobyl health effects should be encouraged.

© Hanna Chang. 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.

References

[1] F. Barnaby, "Chernobyl: The Consequences in Europe," Ambio 15 332 (1986).

[2] J. C. Ricarte-Filho et al., "Identification of Kinase Fusion Oncogenes in Post-Chernobyl Radiation-Induced Thyroid Cancers," J. Clin. Invest. 11, 4935 (2013).

[3] L. B. Zablotska et al., "Analysis of Thyroid Malignant Pathologic Findings Identified During 3 Rounds of Screening (1997-2008) of a Cohort of Children and Adolescents From Belarus Exposed to Radioiodines After the Chernobyl Accident," Cancer 121, 457 (2015).

[4] S. Kikuchi et al., "Latency Period of Thyroid Neoplasia After Radiation Exposure," Ann. Surg. 239, 536 (2004).

[5] K. Walmsley, "26 Years On: Helping Chernobyl's Children," CNN, 25 Apr 12.