Detection of 210Po by CR-39 from filter papers used in 1984 for measuring radon daughters in a room

The correlation between the environmental level in a room of short lived radon daughter products and the long lived alpha emitting Po-210 decay product was studied using CR-39 track detectors. Filter papers were used to collect radon daughters and thus to measure the working levels in-situ. These filters were stored after the experiment, and were used five years later to study the activity of the long-lived alpha emitting daughter, Po-210 (138 days half life). This isotope is separated from the short-lived daughters by Pb-210 (beta emitter with 22 years half life). The CR-39 detectors were placed on the surfaces of different filters for 3 months for two different post-sampling times. The counting results showed very good correlation with the environmental activities of 5 years earlier. (author)