Thoron concentration, aerosol characteristics of super(212)Pb and estimation of equivalent dose

The thoron gas ([sup 220]Rn) activity concentration as well as activity size distribution of unattached and attached [sup 212]Pb to aerosol particles was measured in the open air of Jeddah City, Kingdom of Saudi Arabia. An electroprecipitation method was applied for measuring the 220Rn concentration. A mean activity concentration of 220Rn was determined to be 1.80 + or - 0.47 Bq m[sup -3]. The unattached activities of [sup 212]Pb were collected using the wire screen diffusion battery technique while a low-pressure cascade impactor collected the attached activities. With a dosimetric model calculation (ICRP, 1994) the total and regional deposition fractions, total and regional equivalent doses could be evaluated considering the obtained parameters of the activity size distributions. This paper talks about the thoron concentration, aerosol characteristics of [sup 212]Pb and estimation of equivalent dose.