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Health Effects of Exposure to Radon: BEIR VI
TABLE B-13 Properties of the 220Rn decay chain
Type of Radiation
Radiation Energies (Move)
0.67, 0.93, 1.55, 2.27
1.796, 1.28, 1.52
2.6146, 0.5831, 0.5107
across the volume of a room because of the short half-life. Consequently, it is difficult to define representative values of 220Rn. Thus, most of the available measurements have been made of the 220Rn progeny rather than 220Rn. The available data for the ratio of PAEC arising from 220Rn decay products to that from 222Rn are summarized in Table B-14. Rannou (1987) has examined the variation of the PAEC(220Rn) as the PAEC(222Rn) changes and found that
PAEC(220Rn) = PAEC (222Rn)0.4 (4)
so that the exposure from the 222Rn progeny increases more rapidly than the 220Rn decay products. Thus, for dwellings with high 222Rn concentrations, it appears
TABLE B-14 Approximate ratio of PAEC for 220Rn progeny to 222Rn progeny at various locations (Schery 1990)