The duration for which radiation persists in the air after a nuclear bomb detonation depends on the specific type of radiation released, the altitude of the detonation, and other factors.
There are two primary types of radiation of concern in this context: initial radiation and residual radiation.
Initial Radiation: Initial radiation consists of high-energy gamma rays and neutron radiation released during the first minute following a nuclear explosion. This radiation dissipates relatively quickly. Within minutes to hours, the initial radiation levels decrease significantly, making it unsafe for immediate exposure but less hazardous over time.
Residual Radiation: Residual radiation refers to the radioactive fallout that occurs after a nuclear explosion. It includes both short-lived and long-lived radioactive isotopes. Short-lived isotopes decay relatively quickly, while long-lived isotopes persist for longer periods.
The dispersion and fallout of residual radiation depend on various factors, such as weather conditions, wind patterns, and the type of detonation (airburst, surface burst, etc.). Fallout can contaminate the air, soil, and water in the vicinity of the explosion.
The time duration for which residual radiation remains in the air varies widely. It can range from a few hours to several days or even longer for some isotopes. However, it's important to note that the radiation levels typically decrease rapidly with distance from the blast site.
To assess the specific duration and impact of radiation in a particular scenario, it's crucial to consider expert analysis and data from relevant sources, such as government agencies specializing in nuclear emergencies, radiation protection organizations, and scientific studies.