The time modes of neutron activation analysis of samples of natural environments were experimentally optimized based on the nuclear-physical characteristics of the studied and "interfering" radionuclides. The detection limit and the accuracy of element detection were chosen as criteria for optimizing the method. The analysis of metrological parameters of neutron activation analysis allowed us to conclude that the detection limit is low, reproducibility is satisfactory and correctness is correct, which favors the use of the method in quality control of various natural environments. Keywords: objects of the natural environment, atmospheric aerosols, environmental pollution, neutron activation analysis, optimization of time modes, determination limit, gamma radiation, gamma spectrometry, half-life, radionuclide activity, element isotope, analysis error, radioactive decay, analytical peak, determination accuracy, statistical error, photo peak area. "interfering" radionuclides,

www.easij.com Special Issue, Issue#2, Volume#2, August 2020.