Which of the following is an example of a prompt somatic effect?

Prompt somatic effects are those biological effects that occur shortly after exposure to radiation, typically within hours to days. Hair loss is a classic example of a prompt somatic effect because it can manifest fairly quickly following high-dose radiation exposure, particularly in cases where the radiation affects the scalp and hair follicles.

In contrast, the development of cancer, birth defects, and delayed growth are classified as delayed effects. These outcomes usually arise after a longer latency period following radiation exposure. For instance, cancer can take years or even decades to develop, making it a delayed effect rather than a prompt one. Similarly, birth defects often occur as a result of exposure during critical periods of fetal development, which also does not fall under the category of prompt effects. Delayed growth is associated with long-term exposure and impacts that can develop gradually, rather than immediately.

Thus, hair loss accurately represents a prompt somatic effect due to its relatively rapid onset following significant radiation exposure.