Which of the following is classified as a prompt somatic effect?

Prompt somatic effects are biological responses that occur shortly after exposure to ionizing radiation, typically within a few minutes to days. Skin redness, medically known as erythema, is a classic example of a prompt somatic effect. It arises from radiation-induced damage to skin cells, leading to an inflammatory response that manifests as erythema. This immediate response highlights the acute effects of radiation exposure on living tissue.

In contrast, cancer is classified as a late somatic effect as it often develops over a longer period, making it a long-term consequence of radiation exposure. Genetic damage pertains to changes in DNA that can be passed to future generations but do not have immediate somatic effects. Cataracts, while they can be caused by radiation, are also considered a later somatic effect, with symptoms often not appearing until years after exposure. Therefore, among the options provided, skin redness stands out as the prompt somatic effect due to its quick manifestation following radiation exposure.