Equivalent dose rate of ionizing radiation above water reservoirs in Vilnius

The paper discusses search of possible pollution sources of natural radionuclides; the measuring method (using the GPS system) of the equivalent dose rate of the environment is introduced; the equivalent dose rate of water reservoirs of Vilnius is measured; the values and variations of equivalent dose rate are evaluated; it is found that the values cover the range from 10 nSv/h to 85 nSv/h; it is noticed that the values measured above water are distinctly less than the equivalent dose rate above the soil surface; comparative analysis between the equivalent dose rate of open water reservoirs of Vilnius and other rivers and lakes of Lithuania is carried out.