How many REMs of radiation were in the atomic bombs dropped on japan?

The atomic bombs dropped on Hiroshima and Nagasaki in August 1945 released significant amounts of radiation, but quantifying it in REM (Roentgen Equivalent Man) can be complex. Estimates suggest that the immediate radiation exposure for those near the epicenter of the blasts was around 300 REM or more, with varying doses experienced by survivors further away. Long-term effects from residual radiation and fallout also contributed to increased cancer risks and other health issues among the survivors.