Which condition is characterized by acute symptoms occurring within hours of exposure and lasting for 1-2 days?

The condition characterized by acute symptoms that occur within hours of exposure and last for 1-2 days is known as prodromal syndrome. This syndrome typically manifests shortly after a significant radiation exposure and includes symptoms such as nausea, vomiting, fatigue, and other non-specific initial symptoms. These effects are often transient and indicative of the body's immediate response to radiation.

In the context of radiation exposure, prodromal syndrome arises from the rapid onset of cellular damage due to acute radiation sickness. It serves as an initial warning sign of the impact of radiation on the body, allowing for further evaluation and necessary medical intervention.

The other options represent conditions with different characteristics and timelines. For instance, cataracts develop as a long-term consequence of radiation exposure and do not present with acute symptoms shortly after exposure. Centrifugal syndrome and hematologic syndrome refer to specific clinical presentations or complications resulting from radiation but do not fit the acute time frame of symptoms described in the question.