Effect of Extensive Use of Granite Countertops on the γ-Radiation Dose to Occupants of the New Buildings of King Abdulaziz University

Exposure dose due to γ-radiation was measured in the new buildings of King Abdulaziz University using an advanced car-borne monitoring system to evaluate the effect of the extensive use of granites on the exposure dose rate to occupants. The measurements were conducted inside and outside the new buildings. For comparison, measurements inside the old buildings of limited granite use were conducted. The results indicated that the average exposure dose rate in the corridors of granite countertops was 0.115 μSv/h compared to 0.093 μSv/h in corridors of marble floors in the old buildings. About 4.2% increase in the annual effective dose due granite use was estimated. A maximum excess fatal cancer risk to an individual working in the new buildings due to exposure to excess γ-radiation from granite countertops was estimated by 1.4x10-6. The obtained results are discussed in detail and some conclusions are drawn.