Current Concentrations of Radionuclides and Estimated Radiation Doses around the Chernobyl Nuclear Power Plant, the Semipalatinsk Nuclear Testing Site, and in Nagasaki

To evaluate current environmental contamination and risks from internal and external radiation exposure due to the accident at the Chernobyl Nuclear Power Plant (CNPP) and Semipalatinsk Nuclear Testing Site (SNTS), concentrations of radionuclides in edible mushrooms, soils and stones from these areas were analyzed by gamma spectrometry. Annual effective doses were calculated by cesium contaminations. Concentrations of ¹³⁷Cs in mushrooms were 2635.0±1.2 Bq⁄kg in Korosten city (around CNPP), 2449.6±1.7 Bq⁄kg in Gomel city (around CNPP), 2.8±0.1 Bq⁄kg in Semipalatinsk city, and 1.7±0.1 Bq⁄kg in Nagasaki, respectively. Concentrations of ¹³⁷Cs in soils were same tendency to mushrooms. Four artificial radionuclides were detected from stones of Lake Balapan in SNTS (²⁴¹Am, ¹³⁷Cs, ⁵⁸Co and ⁶⁰Co). Calculated effective doses of ¹³⁷Cs were 0.26 mSv⁄y in Korosten city (around CNPP), 0.23 mSv⁄y in Gomel city (around CNPP), 0.060 mSv⁄y in Minsk (around CNPP), 0.00057 mSv⁄y in Semipalatinsk city, and 0.00013 mSv⁄y in Nagasaki, respectively. Our present study revealed that although radiation exposure potency still exists around CNPP, estimated annual dose is below the public dose limit of 1 mSv⁄y (ICRP1991). Also, Lake Balapan in SNTS is still contaminated by artificial radionuclides derived from nuclear tests. Long-term follow-up of environmental monitoring around CNPP and SNTS, as well as evaluation of health effects in the population residing around these areas, will be available, in order to reduce unnecessary exposure of residents.