Uranium isotopes in food and effect on health of Southern Kazakhstan citizens.

Natural uranium isotopes were determined in food products of the Kyzylorda region in Kazakhstan. This region is characterised by the influence of the uranium industry, as up to 15% of the world uranium reserves are concentrated in this part of Kazakhstan and the adjacent territory of Kyrgyzstan. The food products most consumed by locals were selected for this survey. Special attention was paid to the analysis of edible and non-edible parts of food products and the assessment of a possible increase in risk due to consumption of non-edible parts. The highest content of uranium, of 80.2 µg/kg, was found in the edible part of the carrot. The highest activity concentrations of uranium isotopes are found in carrot, potato and onion, as edible parts of these vegetables are grown in the soil. All estimated cancer risks for uranium isotopes range from 10-14 to 10-12, which are insignificant values.

Uranium series radionuclides in surface waters from the Shu river (Kazakhstan).

The concentrations of (238)U, (234)U, (226)Ra, (210)Po and (210)Pb have been determined in surface waters collected along the course of the Shu River, lying on the border between Kazakhstan and Kyrgyzstan. In the study area, the river runs through some of the largest uranium deposits worldwide, which were actively exploited during the nuclear weapons and nuclear energy programmes of the former Soviet Union. The data show an increasing trend in uranium concentrations downstream the river from the city of Tokmak to the city of Shu, with good correlation between total uranium concentrations and total dissolved solids. Data on uranium isotopes disequilibrium show the presence of technogenic uranium inputs into the Shu River downstream from the city of Karasu, evidenced by a decrease in the measured (234)U/(238)U isotopic ratio from 1.63 in uncontaminated sites to 1.29 in sites affected by past mining activities.