The Semipalatinsk nuclear test site (STS) in the Republic of Kazakhstan was an important site for testing atomic bombs and other civil and military nuclear devices of the former Soviet Union. Results are presented from investigations on the extent of radiostrontium contamination in soils and vegetation at the technical areas of the STS, where the tests were conducted and in pastures used by farmers for grazing animals or for hay production. Our data are compared with those reported largely in the recent Russian language literature that has been reviewed. The extent of (90)Sr contamination of soil is highly variable over the STS with the highest values associated with the technical areas, particularly the Degelen mountains. Recently measured values in both the present data and the Russian language literature confirm the relatively high current contamination of soil and vegetation in the vicinity of tunnels and associated watercourses in the Degelen area. The proportion of (90)Sr in soil which could not be extracted with 6 M HCl was only an average of 20%, which is low compared to other test site areas and possibly indicates a relatively high mobility in this area, because the (90)Sr is derived from leakage from explosion tunnels along watercourses rather than being associated with fused silicates. A comparison of relative activity concentrations in soil and vegetation suggests that the transfer of (90)Sr to vegetation on the STS is high compared to that of (137)Cs and plutonium.

The Semipalatinsk Test Site in Kazakhstan was one of the major sites used by the USSR for testing nuclear weapons for more than 40 y. Since the early 1990's, responsibility for the site has passed to the Kazakh authorities. There has been a gradual re-establishment of agricultural use such as horse and sheep farming. Therefore, it has become important to evaluate the current and future risk to people living on and using the contaminated area. Internal dose assessment is one of the main components of the total dose when deriving risk factors for population living within the test site. Internal doses based on food monitoring and whole body measurements were calculated for adults and are in the range of 13-500 microSv y(-1) due to radiocesium and radiostrontium.

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