SICH-9.1--a unique whole-body counting system for measuring SR-90 via bremsstrahlung. The main results from a long-term investigation of the Techa River population.

A unique body counting system (SICH-9.1) has been constructed which allows an in vivo determination of body burdens of Sr-90 with high accuracy. To date about half of the population residing in the Techa River basin has been examined using this counting system. The information on the dependence of Sr-90 content in the human body on time, age and sex presents a unique basis for studies of metabolism of this element. The data base containing the findings of the above-described measurements has established a foundation for the reconstruction of individual and collective doses in the Techa River population.