DR.TSUBOKURA'S RADIATION LECTURE VOL.170

Author: Masaharu Tsubokura M.D., PhD.

Editor: Yudai Kaneda

339　 After the disaster, the postpartum depression trend has been high

7 August 2021

In March of this year, the latest report from the UN Scientific Committee on the Effects of Atomic Radiation reported that the possibility of an increase in cancer associated with radiation exposure is low. On the other hand, the report also states that the health effects, such as psychological effects and lifestyle-related diseases caused by changes in the living environment, were enormous.

　The effects of pregnancy and childbirth have been extensively studied in a survey (i.e., one of the prefectural health surveys) of pregnant and nursing mothers. The results show that since 2011, the premature birth rate, low birth-weight rate, and congenital malformation rate have been 5%, 5%, and 5%, respectively. Our prefecture’s values were not different from the national average or from the generally accepted data. In addition, based on past findings, there is absolutely no reason to be concerned about genetic effects.

　On the other hand, the number of mothers suffering from depression was slightly higher than the national average was after the earthquake. The percentage of those with depressive tendencies has been improving over time. However, it is also known that depressed tendencies are higher among mothers who gave birth soon after the disaster, even in long-term follow-ups.

　The Prefectural Health Care Center provides ongoing support for people facing depression, including telephone consultations and collaboration with specialists and community officials when necessary.

340　 Internal exposure is extremely low

14 August 2021

The cafeteria at the athletes’ village for the Tokyo Olympics and Paralympics was well received because it uses ingredients from the areas affected by the earthquake and tsunami, including our prefecture. Since this has become a bit of a hot topic, I would like to review internal radiation exposure again.

　Current internal exposure, if any, occurs from food. Inhalation from the air need not be considered. A variety of radioactive materials exists, but the current nuclear accident has mainly affected cesium; other radioactive materials are too small in quantity to be of concern. Cesium (cesium-134 and cesium-137) is the problem. The half-life of cesium-134 is about 2 years, whereas that of cesium-137 is about 3 years.

　Repeated testing has revealed that the degree of contamination varies with the type of food. For example, open-pollinated mushrooms, wild vegetables, and game meat were initially somewhat susceptible to contamination. However, from the early stages of the accident, shipments of easily contaminated items were restricted and were regulated, and especially in the past few years, internal exposure tests using whole body counters have shown that almost everyone’s exposure is below the detection limit. In the tens of thousands of tests conducted in the years after the accident, even the highest exposure dose never reached the level of a single CT scan of the head.

　Furthermore, 10 years have passed since the accident, and the risk has been greatly reduced. This is the result of the efforts of various stakeholders, including producers, consumers, and the government. Currently, there is no situation where internal exposure can occur from ingestion of distributed food.

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The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, on 7 and 14 August 2021 were reproduced for MRIC Global under the author's permission.