Assessment of contamination of the Issyk-Kul' valley natural waters with uranium mine wastes

Abstract
The Lake Issyk-Kul' of the central Tyan-Shan is characterized by increased natural uranium content. Uranium-carbon deposit situated on the southern bank of the Lake can be the reason of chemical and radioactive contamination of this unique basin by exploitation wastes. ln order to estimate possible danger, a project "Assessment and prognosis of environmental changes in Lake Issyk-Kul' (Kyrghyzstan)" was developed and supported by the Program ofthe European Commission "Copernicus-2" (2001-2003). According to this project the water assays were sampled from different depths near the banks of the Lake and from low-debit sources draining the dumping grounds of the uranium-carbon deposit. Elemental and isotopic examinations of these water samples were performed using an ELEMENT HR-ICP-MS (Finnigan Mat). The results obtained are the evidence that the ecological status of the Lake Issyk-Kul'is not damaged at present. Wastewaters from the uranium-carbon mine do not make decisive contribution into the natural radioactive background.