C. Dose Estimation from Residual and Fallout Radioactivity 1. Areal Surveys

Review of Thirty Years Study of Hiroshima and Nagasaki Atomic Bomb Survivors I. DOSIMETRY

Abstract

External dose rates and cumulative doses for early entrants from areal surveys and simulated experiments are reviewed. The average cumulative doses to infinity at the hypocenters were 101 rad in Hiroshima and 32 rad in Nagasaki, with a variation of about 60 percent.
Radioactive fallout areas nearly matched the “black rain” areas in Nagasaki and in Hiroshima. Radioactivity in the fallout areas was affected by radioactive decay and by the leaching and dissipation by rains. Considering these factors, the cumulative dose to infinity in the fallout area of Hiroshima was estimated to be 13 rad, excluding internal radiation doses from inhaled and ingested radionuclides. Attempts to estimate radiation dose from internally deposited radionuclides are also described.