Long-term determination of airborne concentrations of unattached and attached radon progeny using stacked LR 115 detector with multi-step etching

We developed the theoretical basis for long-term determination of airborne concentrations of unattached and attached radon progeny. The work was separated into two parts. First, we showed that (stacked and multiply etched) LR 115 detectors could be used to determine airborne concentrations of the short-lived radon progeny, ²¹⁸Po and ²¹⁴Bi. The equilibrium factor F between radon and its progeny could then be determined through the use of the reduced equilibrium factor F_red. The airborne concentrations of ²¹⁴Pb could then be determined. Second, we developed a method based on the airborne concentrations of ²¹⁸Po, ²¹⁴Pb and ²¹⁴Bi to determine the parameters of the Jacobi room model, viz., the ventilation rate λ_v, aerosol attachment rate λ_a, deposition rate of unattached progeny λ_d^u and the deposition rate of attached progeny λ_d^u. With these parameters, the unattached fraction f_p of the potential alpha energy concentration could also be determined. Knowledge of f_p, together with F, would enable more accurate determination of the effective dose in the human lung. © 2009 Elsevier B.V. All rights reserved.