ปีที่ ๓๒ ฉบับที่ ๓ กรกฎาคม-กันยายน ๒๕๕๐

«“√ “√ √“™∫— ≥±‘ µ¬ ∂“π ‰æ±Ÿ √¬å «√√≥æß…å ·≈–§≥– 573 ªï ∑’Ë ÛÚ ©∫— ∫∑’Ë Û °.§.-°.¬. Úıı Abstract Determination of Radon Gas Emanating from Concrete Slabs Containing Phosphogypsum Paitoon Wanabongse Udorn Youngchuay Jantanee Jamsangtong Thailand Institute of Nuclear Technology, Vibhavadi Rangsit Road, Chatuchak District, Bangkok 10900 Touchaphong Srisuwan Thammasat University, Rangsit Campus, Phaholyothin Road, Klong Luang District, Pathumthani 12120 Somchai Bovornkitti Fellow of the Academy of Science, The Royal Institute, Thailand Phosphogypsum (Pg), an industrial by-product of a fertilizer production plant, was utilized as adjuvant material in concrete slabs used as building materials. This study was carried out in order to assess the amounts of radon gas emanating from various types of the Pg-containing concrete slabs, namely, plain slabs, slabs surfaced with cement, slabs surfaced with cement and covered with wallpaper or with plastic/oil paints, compared with that emanating from concrete slabs without Pg. The findings revealed that the non-surfaced Pg slabs emitted the highest amounts of radon, while the plain non-Pg slabs emanated the least. The emanation activity of radon from the concrete slabs was ameliorated to a certain extent by surfacing the slabs with cement, or by lining cemented and covered slabs with wallpaper or paint on top of the cemented surface. Slabs covered with plastic paint showed the highest suppression of radon emanation. Key words : radon, concrete slab, phosphogypsum, wallpaper, paint