Measurement of Indoor Radon-222 andRadon-220 Concentrations in Central Japan

摘要

A passive-type radon/thoron detector was used for measuring indoor radon and thoronconcentrations at 90 dwellings in Aichi and Gifu prefectures in central Japan during 90 days fromDecember, 2006 to March, 2007. The radon and thoron concentrations were 21.1 Bq/m3 and 25.1 Bq/m3,respectively. The dose due to radon and thoron in dwellings was roughly evaluated as 0.7 mSv/y and 2.4mSv/y, respectively. The examination of the geological factor and house condition having an effect onindoor radon concentration was performed.