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