What biological effect may occur immediately after high radiation exposure?

Acute radiation syndrome (ARS) occurs immediately after high radiation exposure and is characterized by a set of symptoms that manifest within hours to days following the exposure. This syndrome can develop when an individual receives a significant dose of radiation in a short period, typically affecting the bone marrow, gastrointestinal tract, and central nervous system.

The symptoms of ARS can include nausea, vomiting, fatigue, and a decrease in blood cell counts due to bone marrow suppression. Prompt medical intervention is crucial in managing ARS, as the severity of symptoms can vary depending on the level of radiation exposure.

In contrast, delayed radiation syndrome refers to effects that occur after a longer latency period following exposure, while chronic radiation exposure describes long-term effects of low doses of radiation over time, which would not manifest immediately. Minor skin irritation may occur after radiation exposure but does not encompass the spectrum of systemic effects seen in ARS. Therefore, the most appropriate choice for the immediate biological effect following high radiation exposure is acute radiation syndrome.