1. Distribution of natural radioactivity and radiological hazard in Saudi Arabia building material used in Jordan market By
Mr. Ismail Abdul Aziz Mohammed Alnkhali
Dr. Mohammad Abu Shayeb
Physics Department , Al Zulfi college of Science

2. Abstract
The concentrations of 226Ra, 232Th and 40K are measured in building material collected from different locations .The collected building materials are analysed using gamma ray spectrometry. The activity concentration of the naturally occurring radionuclides 226Ra, 232Th and 40K in building material it varies from 12.6 to 121.4, 13.6 to 142 and 69.5 to Bqkg_1, respectively. The radium equivalent activity, absorbed dose rate, annual effective dose and hazard index are also calculated for the assessment of radiological risk. The rock formation and chemical properties are responsible for the radionuclides rate in the sample. .

3. Introduction
About 96% of total radiation dose is from natural sources exists in various geological formations such as soils, rocks, sediments, vegetation, water and air, while 4% is of artificial origin.Building materials consist various amounts of natural radioactive nuclides i.e. thorium (232Th), radium (226Ra)and potassium (40K).35, 30 and 400Bqkg-1, respectively is the worldwide average concentration of radium, thorium and potassium. To evaluate the radiation hazards, estimation the natural radioactivity level in soils are very important

4. Numerical Simulation and Algorithms
External hazard index (Hex)
Hex = (CRa/370) + (CTh/259) + (CK/4810)
internal hazard index (Hin).
Hin = (C/185) + ( CTh/259) + (CK/4810)
the indoor air absorbed dose rate (D)
D(nGy h-1 ) = 0.92CRa CTh CK
The annual effective doses outdoor and indoor
Indoor (nSv) = (absorbed dose ) nGyh-1 x 8760h x 0.8 x 0.4SvGy-1
Outdoor (nSv) = (absorbed dose ) nGyh-1 x 8760h x 0.2 x 0.7SvGy-1

6. Maximum radium, thorium and potassium concentration in building material sample at Ma’an and Amman market

7. radium equivalent ratio in building material sample at Ma’an and Amman market0

8. internal hazard index and external hazard index ratio in building material sample at Ma’an and Amman market

9. Conclusion
1. The measurement results of natural radioactivity commonly used in building materials of Ma’an and Amman , Jordan show that the specific activities of 226Ra , 232Th and 40K range from( 12.6 to 121.4, 13.6 to 142 and 69.5 to Bqkg_1) , respectively , which are in the range of Jordan soil values
2. The average values of indoor air absorbed dose rate for all building materials in the range to the world population
and the annual effective dose rate values of roof tile, glazed tile made from fly ash does not exceed the recommended limit of (1mSvy_1).

10. Thank You