Measurements of indoor gamma radiation dose in At-Taif city, Saudi Arabia using CaSO4:Dy (TLD-900)

This paper describes measurements of indoor gamma radiation dose in At-Taif city, Kingdom of Saudi Arabia. CaSO(4):Dy thermoluminescence dosemeters were used for the detection of gamma radiation in 250 houses within the city. The values of indoor gamma radiation dose rate measured ranged between 90 and 221 nGy h(-1) for the time interval from September 2002 to September 2003. The measured dose varied with the type of house and season of the year. The highest average value 192 +/- 7 nGy h(-1) was measured inside apartments made of cement and brick (157-221 nGy h(-1)), and the lowest average value 92 +/- 6 nGy h(-1) in mud houses (58-117 nGy h(-1)). Intermediate values 154 +/- 5 nGy h(-1) (128-177 nGy h(-1)) and 167 +/- 9 nGy h(-1) (144-185 nGy h(-1)) were observed in large halls and villas, respectively. The average indoor gamma radiation dose rate received by the population of At-Taif city is 138 nGy h(-1) and its corresponding annual dose is 1211 muGy y(-1). The calculated mean effective dose to At-Taif city population, assuming an indoor occupancy factor of 80%, is 970 muSv y(-1).