Influence of Short-Lived Radon-222 Daughters Present in Atmosphere on Natural Environmental Gamma-Radiation Field

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Measurements were simultaneously made of the concentrations of short-lived ²²²Rn daughter radionuclides present in the atmosphere at elevation of 1, 10 and 100 m above ground level, of the count rate of unscattered r-rays, and of the exposure rate, the latter two measurements limited to readings at 1 m above ground. The resulting data revealed close correlation of the short-lived ²²²Rn daughter concentrations in the atmosphere with the values at 1 m elevation of the peak count rate for 609 keV ²¹⁴Bi r-rays and of the exposure rate. The exposure rate at 1 m elevation attributable to the short-lived ²²²Rn daughters in the atmosphere was found to have been limited to at most 10% of the total exposure rate during the period of observation covered in the present study.