Indoor 222Rn measurements in Swaziland with the solid state nuclear track detector

CR-39 is very useful in the detection of alpha particles from disintegration of radon and radon daughters. Radon measurements were performed in 57 houses of different types in Swaziland. Using the calibrated sensitivity coefficient of the CR-39 detector, and the measured track densities (bare and filtered), the average value of ground floor radon concentration C0 = 69 Bq m−3, equilibrium factor F = 0.54 and effective dose equivalent HE = 2.84 mSv year−1 were obtained. The radon levels were found to be higher during winter than summer months. In the apartment buildings there was a 30% decrease in radon levels from the ground to the first floor and from the first to the second floor.