Health Effects of Radiation:
5 Themes
Effects on Fetuses and Hereditary Effects

(ii) Effects on fetuses

There are two types of health effects radiation can cause related to pregnancy problems. The first is effects on the fetus at the time of exposure during pregnancy and the second is hereditary effects on children born in the future. Research has been carried out regarding these effects since even before the accident at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi NPS. First of all, let’s look at effects on fetuses.

Deterministic effects and differences depending on the timing of exposure

When a pregnant woman is exposed to radiation and radiation passes through her womb or radioactive materials migrate into her womb, the fetus may also be exposed to radiation.
It is known that fetuses are highly sensitive to radiation and the incidence of effects varies depending on the timing of exposure (time specificity).

  • Exposure to radiation exceeding 100 mSv* at one time is thought to be sufficient to cause the effects above on fetuses. In addition, UNSCEAR has evaluated the maximum exposure dose from the accident at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi NPS as 13 mSv.
Deterministic effects and differences depending on the timing of exposure

* Exposure to radiation exceeding 100 mSv at one time is equivalent to 0.1 Gy of γ-ray or X-ray exposure.

For more information about deterministic effects and differences caused by exposure time periods, see page 98 of Vol. 1, FY2017 edition.

Results of surveys related to the Chernobyl accident

Surveys of the effects on fetuses in the surrounding area continued to be conducted even after the Chernobyl accident.

Results of surveys related to the Chernobyl accident
Source:
*1: Stem Cells 15 (supple 1): 255, 1997 *2: Pediatrics 125:e836, 2010

For more information about reports, see page 101 of Vol. 1, FY2017 edition.

Survey on children born from mothers who were pregnant at the time of the Chernobyl accident

It is considered that radiation exposure during pregnancy does not directly affect intelligence quotients of fetuses and children after growth.

For more information about survey results, see page 100 of Vol. 1, FY2017 edition.

Health Effects of Radiation: 5 Themes