The Chernobyl disaster on April 26th, 1986, led to the emission of radioactive substances such as iodine-131 and radioactive cesium. As the Soviet Union did not control food distribution and intake, residents were exposed to high levels of internal radiation, leading to the internal radiation exposure of the thyroid gland by iodine-131. As a result, the number of people who had thyroid cancer increased drastically among those who had been under 15 years old at the time of the accident. The age predilection is about to move to 25 or older. However, there has been no scientific evidence of impacts for solid tumor other than thyroid cancer, leukemia, benign diseases, or inheritance including unborn babies. On the other hand, the accident was thought to have caused social unrest and mental damage which had far more impact than that caused by radiation exposure. In this paper, we would like to summarize the impacts on the health of the people in Chernobyl compared to those caused by the accident at the Fukushima Daiichi Nuclear Power Plant.