Ecological Systems and Devices Annotation << Back INTERNAL AND EXTERNAL EXPOSURE OF A PERSON TO A RADIATION BACKGROUND G.N. Akhobadze Statistics data on natural radiation depending on geographical points of Earth are given. The main ways of how terrestrial radionuclides enter a human body under its internal oneyear radiation are shown. Types of products that add to the radionuclides entry as consequence of nuclear power plant accidents are presented. Properties and impact of the most dangerous inert gas of radon during natural radiation are demonstrated. Radon concentration in the air in different points of Earth and different construction materials is estimated. Methods for decreasing the radon content in living spaces are proposed and an emphasis on the inadmissible use of construction materials of high specifi c radioactivity is made. Quantitative impact on the radiation dose of anthropogenic sources applied in medicine, science, military hardware, and household equipment is shown. Recommendations for reduction of the radiation dose under medical diagnostics and application of more advanced examination technics are given. Some up-to-date radiometric and dosimetry devices meant for controlling the radiation level both for scientifi c purposes and household ones are shortly analyzed. Keywords: dose; Sievert; concentration; isotope; radiation; biota; half-life; dosage meter. DOI: 10.25791/esip.09.2020.1180 Pp. 40-47.