Abstract
The ambient dose equivalent, H*(10), and the directional dose equivalent, H'(0.07), for indoor and outdoor natural exposure are measured in the Riyadh region, Saudi Arabia. The indoor H*(10) rate varies from 61 to 135 nSv h(-1), while it is in the range of 57-105 nSv h(-1) for the outdoor. The indoor and outdoor rates of H'(0.07) are in the range of 67-142 nSv h(-1) and 59-110 nSv h(-1), respectively. The indoor-to-outdoor ratio of H*(10) is between 0.92 and 1.39, and it is 0.90-1.54 for H'(0.07). The ratio H'(0.07) to H*(10) lies between 1.0 and 1.22 for indoor, while it is 0.97-1.20 for the outdoor.