▁prior ▁to ▁the ▁det on ation ▁and ▁pract iced ▁medicine ▁in ▁communities ▁with ▁poor ▁health ▁care ▁without ▁a ▁permit . ▁ ▁After ▁the ▁det on ation ▁occurred , ▁he ▁was ▁one ▁of ▁the ▁first ▁to ▁observe , ▁document ▁and ▁attempt ▁to ▁treat ▁" atomic ▁bomb ▁sick ness ", ▁now ▁known ▁as ▁ac ute ▁radiation ▁synd rome . ▁Ter uf umi ▁S as aki ▁led ▁int ensive ▁research ▁into ▁the ▁synd rome ▁in ▁the ▁weeks ▁and ▁months ▁post - det on ation , ▁leading ▁to ▁the ▁establishment ▁of ▁three ▁recorded ▁stages ▁of ▁the ▁synd rome . ▁Within ▁ 2 5 – 3 0 ▁days ▁of ▁the ▁explos ion , ▁S as aki ▁noticed ▁a ▁sharp ▁drop ▁in ▁white ▁blood ▁cell ▁count ▁and ▁established ▁this ▁drop , ▁along ▁with ▁sympt oms ▁of ▁fe ver , ▁as ▁pro gn ost ic ▁standards ▁for ▁Ac ute ▁Rad iation ▁Sy nd rome . ▁In ▁the ▁years ▁after ward ▁he ▁would ▁become ▁one ▁of ▁the ▁leading ▁sur ge ons ▁continu ing ▁to ▁document ▁and ▁treat ▁the ▁H ib ak ush a ▁( expl os ion - aff ected ) ▁community , ▁serving ▁as ▁an ▁important ▁source ▁of ▁knowledge ▁for ▁the ▁At omic ▁Bomb ▁Cas ual ty ▁Commission , ▁and ▁later ▁Rad iation ▁Effect s ▁Research ▁Foundation , ▁who ▁began ▁and ▁continue ▁the ▁Life ▁Span ▁Study ▁of ▁atomic ▁bomb ▁surv iv ors , ▁respectively . ▁ ▁D os age ▁▁ ▁The ▁g amma ▁ray ▁do se ▁received ▁by ▁a ▁set ▁of ▁phot ographic ▁film , ▁and ▁therefore ▁those ▁within ▁the