What factor primarily affects the intensity of radiation exposure at a given distance?

The intensity of radiation exposure at a given distance is primarily affected by the distance from the source. As the distance from a radiation source increases, the intensity of radiation exposure decreases significantly due to the inverse square law. This law states that the intensity of radiation is inversely proportional to the square of the distance from the source. Therefore, doubling the distance from the source results in a radiation intensity that is one-fourth as strong, while tripling the distance reduces it to one-ninth, and so on.

Understanding this principle is crucial for maintaining safety in environments where radiation is present, as it underscores the importance of maintaining a safe distance from radioactive sources to minimize exposure. This relationship highlights why, in practice, techniques such as using longer tools, setting up barriers, or employing shielding are fundamental safety measures in industrial radiography.