Base Information Q&A SiteJAEA

Assessment of Exposure Doses and Decontamination


In what ways does exposure to radiation occur the environment? What kinds of radiation exposures are important in Fukushima?

Radiation exposure is classified into two groups. One is external exposure due to radiation coming from outside of human body, and the other is internal exposure caused by breathing air and eating foods.

  1. External exposure
  2. ① Just after the accident
     ・Radiation from radioactive materials in the air
    ② Mid-to-long term
     ・Radiation from radioactive materials deposited on the ground or other materials
  3. Internal exposure
  4. ① Just after the accident
     ・Inhalation of radioactive materials in the air
     ・Ingestion of contaminated food
    ② Mid-to-long term
     ・Inhalation of radioactive materials that were once deposited on the ground and were re-suspended
     ・Ingestion of contaminated foods

Inspection of radioactivity in foods has been properly conducted after the accident, and now radioactivity in the air is quite low (See also;Q How is the concentration of radioactive cesium measured in air? What is the radiation dose by breathing?). Therefore, external exposure is the main route of radiation exposure.