Radon-222 and progeny measurements in "typical" East Tennessee residences

Modified Wrenn chambers for continuous monitoring of 222Rn, featuring several improvements including a computer-assisted electronics package, have been developed at the Oak Ridge National Laboratory. A field test of these instruments was conducted by placing them in the homes of staff members. Field testing was conducted in seven houses for periods ranging from 4 to 18 days. During this testing period, the 222Rn concentration in these houses was monitored continuously. Radon-222 concentrations in the basements of three of the seven houses were in excess of 100 Bq/m3 almost continuously. One residence had instantaneous concentrations approaching 1000 Bq/m3. Samples of soil and building materials from these residences indicated that 226Ra concentrations were in the normal range (40 Bq/kg). Radon progeny measurements were made in five of these houses on a "typical" day. Results obtained were as follows: for basements, a geometric mean of 0.016 WL (geometric S.D. of 2.9); for upper floors a geometric mean of 0.014 WL (geometric S.D. of 2.9). This paper summarizes the results obtained in the field test.