Abstract:
The specific activities of [superscript226]Ra, [superscript228]Ra and [superscript40]K in building material samples were measured. The samples of building materials include 4 types of Portland cement Type-1, rocks and sands from various places. The radium equivalent activities (Ra [subscript eq], absorbed dose rate (D) and hazard index (H[subscriptex], H[subscript in] ) were also calculated. The results showed that the specific activities of the three radionuclides [superscript226]Ra, [superscript228]Ra and [superscritp40]K in portland cement Type-1samples range from 10.92+-0.44 Bq kg[superscript-1] - 75.21+-2.23 Bq kg[superscript-1], 14.27+- 0.57 Bq kg[superscript -1] - 18.10+-0.72 Bq kg[superscritp-1] and 18.93+-1.20 Bq kg[superscritp-1] - 120.32+-3.60 Bq kg[superscript-1], respectively. In sand sample range from 25.12+-0.83 Bq kg[superscript -1] - 30.86+-0.99 Bq kg[superscript-1], 35.13+-1.03 Bq kg[superscript-1] - 55.27+-1.25 Bq kg[superscript-1] and 940.30+-21.21 Bq kg[superscritp-1] - 1131.93+-25.36 Bq Kg[superscript -1], respectively. In rock samples range from 13.12+-0.50 Bq kg[superscript-1] - 15.84+-0.58 Bq kg[superscript-1], 24.01+-0.78 Bq kg[superscritp-1] - 29.05+-0.91 Bq kg[superscritp-1] and 302.88+-7.60 Bq kg[superscript-1] - 417.11+-10.01 Bq kg[superscript-1], respectively. It has been found that sand sample taken from Saraburee Province had the maximum values of Ra[subscript eq], D, H[subscript ex] and H[subscript in] as 197.05+-4.73 Bq kg[superscript-1], 0.86+-0.02 mGy y[superscript-1], 0.53 and 0.61, respectively. The radon exhalation from concrete blocks made of these materials were also measured. The highest radon exhalation level was found to be much lower than the action level which set for building materials by US. EPA.