A registry for exposure and population health in the Altai region affectedby fallout from the Semipalatinsk nuclear test site

A registry of the rural population in the Altai region exposed to fallout f rom nuclear tests at the Semi-palatinsk test site (STS) was established mor e than four decades after the first Soviet nuclear explosion on August 29, 1949. Information about individuals living in an exposed and a control area was collected using all available local sources, such as kolkhoz documenta tion, school registries, medical treatment records and interviews with resi dents. As a result, a database comprising an exposed group of 39179 individ uals from 53 Altai region villages, 6769 external and 3303 internal control s was compiled. For several settlements, effective dose estimates reached t he level of 1.5 Sv, while the average effective dose estimate in the expose d group was 340 mSv. Dosimetric data, vital status information and health r ecords gathered at rayon and village medical facilities are held in the reg istry. Cause-of-death information for deceased residents is obtained from d eath registration forms archived at the Altai region vital statistics offic e. At present, a follow-up of approximately 40% of the population exposed i n 1949 has been done. More will be added by searching for migrants to the l arger towns of the Altai region, i.e. Barnaul, Rubtsovsk and Biisk. In orde r to assess the influence of radiation exposure, analytical studies with a case-control design for stomach and lung cancer are currently being prepare d. The number of known cases is sufficient to detect an odds ratio of 1.5 a t the 95% confidence level. Epidemiological studies in populations affected by fallout from STS may be equally important to the atomic bomb survivors' study for the direct quantification of radiation effects. The range of exp osure rates experienced will extend the acute high-dose-rate findings from Hiroshima/Nagasaki towards acute and protracted lower exposures, which are more relevant for radiation protection issues.