presents up-to-date information on radioactivity released to the atmosphere and the ocean after the accident on the Fukushima Dai-ichi nuclear power plant, on the distribution of radionuclides in the world atmosphere and oceans, and their impact on the total environment (man, fauna, and flora). The book will evaluate and discuss the post-Fukushima situation, emphasizing radionuclide impacts on the terrestrial and marine environments, and compare it with the pre-Fukushima sources of radionuclides in the environment. The authors results, as well as knowledge gathered from the literature, will provide up-to-date information on the present status of the topics. is based on the environmental and nuclear research; however, the presentation will be suitable for university-level readers.