Which of the following is a primary factor in determining the risk of radiation exposure?

The primary factor in determining the risk of radiation exposure is related to both the distance from the radiation source and the duration of exposure. This principle is fundamental in radiation safety; as the distance from a source of radiation increases, the intensity of exposure decreases significantly due to the inverse square law. This means that even a small increase in distance can lead to a substantial decrease in radiation dose received.

Additionally, the duration of exposure is equally critical. The longer an individual is exposed to radiation, the greater the cumulative dose they will receive. Both distance and time together are important components in assessing the overall risk of exposure in radiation safety practices. They influence how much radiation a person is exposed to and help establish protocols to minimize exposure risks in various settings.

The type of equipment used, color of the radiation source, and time of day do not significantly influence the risk of exposure in the same way. Equipment matters regarding its effectiveness and safety compliance but does not inherently alter the basic risk related to distance and time. The color of the radiation source is irrelevant, as radiation itself is not visible. Similarly, the time of day does not affect the exposure levels unless it relates to the operational schedule of specific equipment, which is not a direct risk factor.