Knowledge of the precise life-time radon history in houses is essential for epidemiologists, mitigation professionals and house-owners. For radon dosimetry and to make a reasonable health-risk study similar information about the indoor aerosol environment is necessary. For this purpose a combined data analysis from measurements of the 210Po activity implanted in glass-surfaces as well as trapped in
spongy materials is proposed. This analysis technique provides a characterization of the average indoor
aerosol-particle environment. As a consequence, a radon dose
estimation improves by a factor of about 3 compared to the commonly applied single surface-activity analysis