Whole body counting of radon daughters

This paper reports on five adult males that were exposed for one hour to radon and radon daughter products in an exposure chamber and subsequently measured for radon daughter product activity in the chest region by whole body counting methods. The gamma-ray detection rate was approximated by a single exponential with a 35 minute half period, consistent with the physical decay of a mixture of RaB and RaC. About half of the deposited activity was associated with internal deposition and half with external deposition on clothing, skin and hair. The average counting rate from radon daughters on clothing was 10 times the average from skin and hair. Under as well as outer clothing contributed substantially to the counting rate. A strong correlation was found between internal and external deposition indicating that total activity provides a useful index of internal deposition