Mapping indoor radon-222 in Denmark: design and test of the statistical model used in the second nationwide survey.

In Denmark, a new survey of indoor radon-222 has been carried out, 1-year alpha track measurements (CR-39) have been made in 3019 single-family houses. There are from 3 to 23 house measurements in each of the 275 municipalities. Within each municipality, houses have been selected randomly.

Determining 222Rn diffusion lengths in soils and sediments.

Radon-222 diffusion length has been measured for 28 Danish soils and sediments. Samples were placed in a diffusion column connected to a 222Rn reservoir and the transport of 222Rn through the column was measured. The diffusion length was found by comparing the measured data to time-dependent diffusion theory.

Measurement of the emanation of radon-222 from Danish soils.

The radon-222 emanation from 70 samples of Danish soils, subsoils, and sedimentary rocks has been measured. Two methods have been employed. The first one is to follow the growth of the radon concentration in a radon-tight sample container by transferring small air samples to a scintillation flask detection system.