EVALUATION OF FACTORS INFLUENCING MEASUREMENTS OF ENVIRONMENTAL ~(222)Rn CONCENTRATIONS -1

摘要

A commercially available activated charcoal detector for measuring ~(222)Rn concentrations in air was calibrated with known amounts of ~(222)Rn and examined in terms of air luminescence counts, the optimal elusion time, and the interferences from ~(220)Rn and ~(219)Rn. The results indicate that the detector is simple and reliable for conditions normally encountered indoors. The method has been applied to assay indoor ~(222)Rn concentrations in 387 homes in Tokyo and the adjacent four prefectures, which ranged from 0.7 to 140 Bq/m~3 and averaged 22.7 Bq/m~3.