Dr. Tsubokura's Radiation Lecture Vol.26

Author: Masaharu Tsubokura

Editors: Akihiko Ozaki M.D., Yuki Senoo

51. Screening program is effective for limited types of cancer

In reality, cancer screenings have several downsides: some tests may have limited accuracy in cancer detection, detect non-life-threatening cancer, or cause complications from various interventions.

Considering these negative consequences of the cancer screenings, it is recommended when early diagnosis and treatment is assumed to decrease mortality related to cancer. In other words, only limited types of cancer would benefit from population-level cancer screening programs.

Today, cancer screening programs with widely-accepted efficacy are those for colorectal cancer, cervical cancer, breast cancer, and stomach cancer (in only a few countries, including Japan). It should be noted that cancer screenings are not always advisable for all human organs.

52. Comparison of the level of radiation exposure of thyroid glands between Fukushima and Chernobyl

Thyroid glands absorb iodine contained in foods to produce the thyroid hormone, which is necessary to enhance metabolism.

After the 2011 Fukushima Daiichi nuclear disaster, radioactive iodine spread into our living environment, and our bodies absorbed some of it from the air, water, and food.

However, the level of thyroid glands’ radiation exposure caused by radioactive iodine after this accident was much less than that of the Chernobyl accident. The extent of exposure is associated with the health effects of radiation exposure, such as an increased risk of developing cancer.

The half-life of radioactive iodine is as short as 8 days; therefore, the radioactive iodine no longer exists in our environment.

After the Fukushima Daiichi nuclear disaster, the United Nations, WHO (World Health Organization), and some universities investigated the effect of radiation exposure on thyroid glands in thousands of people.

Although the results of these analyses were slightly different, the level of thyroid exposure in Fukushima undoubtedly was much lower than that of the Chernobyl accident.

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The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, on December 27th of 2015 and January 3rd 2016 was reproduced for MRIC Global under the author's permission.