Environmental Radioactivity In The Plitvice Lakes National Park, Part 2: Living Organisms

We report on a part of a study of the environmental radioactivity in the Plitvice Lakes National Park that was carried out during 2011 and 2012. This part was focused on measuring the activity concentrations of important naturally occurring (40K, 7Be, 238U, 235U, 232Th, 226Ra, 210Pb) and fission produced (90Sr, 134Cs, 137Cs) radionuclides in collected samples of selected living organisms, these being moss, lichen, pine needles, mushrooms, earthworms, and fish. Our results suggest that the radiological load on the local biota was within the limits characteristic of Croatia, exhibiting no indication of negative trends. Only in one moss sample, we found an elevated activity concentration of 137Cs. Taking into account that a low level of radioactivity in inorganic matter from the same environment was found in this study as well, we can conclude that the Plitvice Lakes National Park is a clean area from the point of view of radioecology. (author).