Radionuclide content in some building materials and gamma dose rate in dwellings in Cuba.

摘要

Naturally occurring radionuclides in building materials are one of the sources of radiation exposure ofthe population. This study was undertaken with the purpose of determining radioactivity in some Cuban buildingmaterials and for assessing the annual effective dose to Cuban population due external gamma exposure indwellings for typical Cuban room model. Forty four samples of raw materials and building products werecollected in some Cuban provinces. The activity concentrations of natural radionuclides were determined bygamma ray spectrometry using a p-type coaxial high purity germanium detector and their mean values are in theranges: 9 to 857 Bq.kg~(-1) for 40K; 6 to 57 Bq.kg~(-1) for ~(226)Ra; and 1.2 to 22 Bq.kg~(-1) for 232Th. The radium equivalentactivity in the 44 samples varied from 4 Bq.kg~(-1) (wood) to 272 Bq.kg~(-1) (brick). A high pressure ionisation chamberwas used for measuring of the indoor absorbed dose rate in 543 dwellings and workplaces in five Cubanprovinces. The average absorbed dose rates in air ranged from 43 nGy.h~(-1) (Holguín) to 73 nGy.h~(-1) (Camagüey)and the corresponding population-weighted annual effective dose due to terrestrial gamma radiation was estimatedto be 145 ± 40 μSv. This dose value is 16% higher than the calculated value for typical room geometry of Cubanhouse.