▁H iro sh ima ▁and ▁Nag as aki ▁to ▁see ▁what ▁work ▁was ▁being ▁done . ▁They ▁found ▁that ▁the ▁Japanese ▁had ▁a ▁well - organ ized ▁medical ▁group ▁under ▁the ▁Japanese ▁National ▁Research ▁Council , ▁who ▁were ▁carrying ▁out ▁studies ▁on ▁both ▁immediate ▁and ▁delayed ▁atomic ▁bomb ▁damage ▁in ▁surv iv ors . ▁It ’ s ▁almost ▁impossible ▁to ▁get ▁an ▁exact ▁figure ▁of ▁how ▁many ▁people ▁were ▁killed ▁in ▁the ▁two ▁bomb ings , ▁because ▁both ▁cities ▁had ▁people ▁who ▁had ▁ev acu ated ▁since ▁it ▁was ▁a ▁time ▁of ▁war . ▁H iro sh ima ▁expected ▁bomb ings , ▁since ▁they ▁were ▁an ▁important ▁military ▁supply ▁center , ▁so ▁many ▁people ▁had ▁left ▁the ▁area . ▁There ▁were ▁also ▁people ▁from ▁surrounding ▁areas ▁who ▁would ▁come ▁into ▁the ▁city ▁on ▁an ▁irregular ▁basis ▁to ▁serve ▁in ▁work ▁cre ws . ▁Robert ▁Hol mes , ▁who ▁was ▁director ▁of ▁the ▁AB CC ▁from ▁ 1 9 5 4 - 1 9 5 7 , ▁said ▁that ▁"[ the ▁surv iv ors ] ▁are ▁the ▁most ▁important ▁people ▁living " ▁ ▁The ▁AB CC ▁also ▁drew ▁on ▁the ▁work ▁of ▁Chinese ▁scient ists , ▁who ▁were ▁already ▁studying ▁the ▁surv iv ors ▁in ▁the ▁time ▁before ▁the ▁AB CC ▁arrived ▁in ▁Japan , ▁so ▁there ▁was ▁information ▁from ▁both ▁American ▁and ▁Chinese ▁officials . ▁Mas ao ▁T su zu ki ▁was ▁the ▁leading ▁Japanese ▁authority ▁on ▁the ▁bi ological ▁effects ▁of ▁radiation . ▁He ▁said ▁there ▁were ▁four ▁causes ▁of ▁injury ▁in