title: Natural radioactivity and gamma dose from Sri Lankan clay bricks used in building construction.
abstract: The specific radioactivity concentrations of 226Ra, 232Th and 40K have been determined by gamma ray spectrometry with an HPGe detector in clay brick samples from kiln sites located in 17 towns. The average values of the measured activities are 35, 72, and 585 Bq kg(-1), respectively, for the above radionuclides. The average estimated radium equivalent concentration is 183 Bq kg(-1) and is comparable with reported values for many countries in the world. This value and the value obtained from the criteria formula suggest that the use of local clay bricks do not pose a radiological hazard. The calculated average absorbed dose rate in air within buildings was found to be 102 nGy h(-1) while the population weighted indoor annual effective dose was 0.20 mSv.
authors.affiliation: Radioisotope Centre, University of Colombo, Sri Lanka.
authors.forename: R
authors.initials: R
authors.lastname: Hewamanna
authors.forename: C S
authors.initials: CS
authors.lastname: Sumithrarachchi
authors.forename: P
authors.initials: P
authors.lastname: Mahawatte
authors.forename: H L
authors.initials: HL
authors.lastname: Nanayakkara
authors.forename: H C
authors.initials: HC
authors.lastname: Ratnayake
mesh_terms: D000396:Air Pollutants, Radioactive / Q000009:adverse effects / Q000032:analysis; D000538:Aluminum Silicates; D000077215:Clay; D003252:Construction Materials; D005720:Gamma Rays / Q000009:adverse effects*; D006801:Humans; D011197:Potassium Radioisotopes / Q000009:adverse effects / Q000032:analysis; D011829:Radiation Dosage; D011883:Radium / Q000009:adverse effects / Q000032:analysis; D013051:Spectrometry, Gamma; D013188:Sri Lanka; D013910:Thorium / Q000009:adverse effects / Q000032:analysis
chemical_list: D000396:Air Pollutants, Radioactive; D000538:Aluminum Silicates; D011197:Potassium Radioisotopes; D013910:Thorium; D000077215:Clay; D011883:Radium