Cancer Mortality in Populations in Kazakhstan Subjected to Irradiation from Nuclear Weapons Testing in China; Technical rept. Jan-Dec 2007

摘要

From 1964 to 1981, 24 surface and atmospheric nuclear explosions were conducted in China at the Lop Nor Test Site. As a result of these tests, freshly produced fission products appeared in objects in the environment and in milk in the population points of the Makanchy, Urdzhar, and Taskesken Districts of the Semipalatinsk Province, Kazakhstan, located 900-1,100 km away from the Chinese Test Site. The contamination levels varied within very wide ranges. The radionuclides, in transferring from objects in the environment into food products, led to biological effects on the human body. In 1984 the medical statistics authorities began to record a significant rise in fatal cases of cancer among the populations of the above-noted districts; this rise significantly exceeded the dynamics of cancer distribution in preceding years. Especially significant increases in fatal cancer cases were registered in such primary sites as breast and lung cancer. The purpose of this work was to estimate the effective radiation doses to the population of the southern portions of the Semipalatinsk Province as a result of nuclear weapons tests in China, and to establish a link in the excess cases of malignant cancer with irradiation of the population. In 11 cases, taking the wind into consideration, the Makanchy, Urdzhar, and Taskesken districts were contaminated by fission products. The radiation situation was reconstructed based on archival materials and measurements of the radioactivity in objects found in the environment and in locally produced food products. The internal radiation doses were calculated based on the explosion parameters with regard to the time they were conducted and according to the results of measuring of milk samples taken in specific population points.