International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2557

Full Length Research Paper

Unattached fractions and aerosol attached of radon progeny in indoor air

M. Mohery1,2*, A. El-Hussein1 and S. H. Alddin3 and S. Al Howaity1
  1Physics Department, Faculty of Science, North Jeddah, King Abdulaziz University, Jeddah, Saudi Arabia. 2Physics Department, Faculty of Science, Sohag University, Sohag, Egypt. 3Physics Department, Girls Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
Email: [email protected]

  •  Accepted: 28 May 2012
  •  Published: 26 July 2012



The present study summarizes the experimental data on the activity concentrations of222Rn gas , unattached  and attached  short-lived222Rn progeny 218Po, 214Pb and 214Po in indoor air of Jeddah City, K.S.A. Jeddah  city  lies on the eastern bank of the red sea, South West the Kingdom of Saudi Arabia. The city is located between latitudes 21° 27\ and 21° 30\ N, longitudes 39° 9\ and 31° 12\ E. By means of theoretical model calculation, the unattached fraction (fP) of 218Po, 214Pb of potential alpha energy of 222Rn progeny, the equilibrium factor (F), the attachment rate (X) to aerosol particles in the room air, the attachment coefficient (B) and the deposition rates of unattached (qf) and attached (qa) of 222Rn progeny on walls and other surfaces were calculated. The measurements were performed at different days in three different rooms of same size at low and moderate ventilation rates. An electrostatic precipitation method and a single wire-screen diffusion battery technique were both employed for the determination of 222Rn gas concentration and its unattached progeny, respectively. At low ventilation rate (υ ≤ 0.4 h–1) a mean unattached fraction (fP) of 0.096±0.01 was obtained at a mean aerosol particle concentration (Z) of 2.6×103 cm–3 and at a mean equilibrium factor (F) of 0.34 ± 0.02. The mean deposition rates of unattached (qf) and attached (qa222Rn progeny were found to be 94±13 h–1 and 0.12±0.05 h–1, respectively. The values of the recoil factor were neglected. At moderate ventilation rate of υ = 0.5 h–1 a mean value of fP = 0.059±0.006 was obtained at a mean aerosol concentration Z = 29×103 cm–3 and at a mean F = 0.24±0.014. In this case the mean value of the recoil factor was found to be 0.54±0.18.      


Key words: Unattached fraction, aerosol attached, theoretical model calculation, radon progeny.