Introduction and Summary

Correlation between the working level of short lived radon daughters and the long lived alpha emitters Po-210 product were studied using CR-39 track detectors.Filter papers used to collect radon daughters and thus to measure the working levels in-situ.Those filters stored after the experiment, and were used after five years to study the activity of the long-lived alpha emitter daughter, Po-210 (138 days half life) of radon.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 surfaces of different filters for 3 months in two different post-sampling times.Counting results showed very good correlation with the working level activities 5 years ago