This study is based on a registry containing medical and dosimetric da
ta of the employees who began working at different plants of the Mayak
nuclear complex between 1948 and 1958 who developed chronic radiation
sickness, Mayak is the first nuclear weapons plutonium production ent
erprise built in Russia and includes nuclear reactors, a radiochemical
plant for plutonium separation, and a plutonium production plant, Wor
kers whose employment began between 1948 and 1958 exhibited a 6-28% in
cidence of chronic radiation sickness at the different facilities, The
re were no cases of chronic radiation sickness among those who began w
orking after 1958, Data on doses of external whole-body gamma-irradiat
ion and mortality in workers with chronic radiation sickness are prese
nted.