Radon in Saudi houses

A total of 637 passive radon dosemeters (CR-39 nuclear track detectors in a closed chamber) were used in a survey of 400 houses in Saudi Arabia. The radon concentration was found to vary from 5 to 36 Bq.m^-3 (0.13 to 0.98 pCi.l^-1) with a mean of 16 Bq.m^-3 (0.43 pCi.l^-1). The unoccupied houses showed a concentration of 29 ± 7 Bq.m^-3 (0.78 ± 0.19 pCi.l^-1) double that of the occupied houses, 14 ± 1 Bq.m^-3 (0.39 ± 0.02 pCi.l^-1), in the same area. The radon daughter concentration measured with a Working Level monitor in 17 unoccupied houses was found to vary from 1.35 x 10^-3 to 24 x 10^-3 WL with an average of 6.9 ± 1.4 x 10^-3 WL. The average exhalation rate measured in 37 houses by 95 passive detectors in cans sealed to the walls ranged from 0.013 to 0.044 Bq.m^-2.h^-1 (0.35 to 1.2 pCi.m^-2.h^-1) with an average of 0.021 ± 0.003 Bq.m^-2.h^-1 (0.56 ± 0.09 pCi.m^-2.h^-1). This survey is the first in Saudi Arabia (a hot climate) and can usefully be compared with similar surveys in countries with cold climates.